TechWiki - User contributions [en-gb]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:47:21Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original_backplate_removed.jpg]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New_backplate_dimensions.jpg]]

[[File:New_backplate_ready_for_fitting.jpg]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fittings.jpg]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulica_connected.jpg]]

[[File:Location_of_hydraulic_fittings_outside.jpg]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:19:47Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original_backplate_removed.jpg]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New_backplate_dimensions.jpg]]

[[File:New_backplate_ready_for_fitting.jpg]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fittings.jpg]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulica_connected.jpg]]

[[File:Location_of_hydraulic_fittings_outside.jpg]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:18:05Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original_backplate_removed.jpg]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New_backplate_dimensions.jpg]]

[[File:New_backplate_ready_for_fitting.jpg]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fittings.jpg]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics_connected.jpg]]

[[File:Hydraulics_from_outside.jpg]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:16:40Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original_backplate_removed.jpg]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New_backplate_dimensions.jpg]]

[[File:New_backplate_ready_for_fitting.jpg]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.jpg]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics_connected.jpg]]

[[File:Hydraulics_from_outside.jpg]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:15:06Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original_backplate_removed.jpg]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New_backplate_dimensions.jpg]]

[[File:New_backplate_ready_for_fitting.jpg]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:13:48Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_house.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:10:13Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling_clutch_housing.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:08:12Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before_drilling.jpg]]

After drilling:

[[File:After_drilling.jpg]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:07:22Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.jpg]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:05:22Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:Flange_dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:03:11Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The_SAAB_type_flange_dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:01:59Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T14:01:05Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:59:52Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

https://wiki.seloc.tv/images/thumb/0/08/The_SAAB_type_concentric_clutch_cylinder.jpg/90px-The_SAAB_type_concentric_clutch_cylinder.jpg

[[File:The SAAB type concentric clutch cylinder.JPG]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

File:A PG1 gearbox fitted with SAAB concentric clutch cylinder.jpg

2022-08-05T13:52:10Z

EliseS1 man:

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:50:27Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A_PG1_gearbox_fitted_with_SAAB_concentric_clutch_cylinder.jpg]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

[[File:The SAAB type concentric clutch cylinder.JPG]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:46:23Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A PG1 gearbox fitted with SAAB concentric clutch cylinder.JPG]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

[[File:The SAAB type concentric clutch cylinder.JPG]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

'''Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:41:28Z

EliseS1 man:

'''Get a smooth and a well proven solution using a SAAB cylinder'''

The Powertrain PG1 gearbox of Rover origin is renowned for its strength and to be easy to work on. It was fitted to the Lotus Elise S1 but first and foremost to a lot of Rover cars.

The clutch is operated by an external hydraulic slave cylinder acting on a lever rotating a shaft. The shaft extends into the clutch housing where it swings a fork acting on a clutch release bearing. The quite long transmission route with levers, bearings and brackets underway adding flex and friction from the cylinder to the release bearing is not ideal.

Most modern cars use a concentric slave cylinder fitted around the gearbox input shaft and the cylinder acts directly on the release bearing. Swedish car manufacturer SAAB was among the first to use this simple but effective solution in mass produced cars, for instance on the SAAB 900 Combi Coupe from 1985. It was used on some Opel/Vauxhall models as well.

[[File:A PG1 gearbox fitted with SAAB concentric clutch cylinder.JPG]]

Likewise some gearbox companies design their racing transmissions for use of the SAAB pattern clutch cylinder.

[[File:The SAAB type concentric clutch cylinder.JPG]]

The SAAB concentric clutch cylinder (part no 4776308) is no longer available as an original spare part but a lot of aftermarket part manufacturers still produce it. Some fabricate it with a cast iron body and others with an aluminum body, the latter being the lightest and most attractive for lightweight Lotus use.

Both AP Racing and Tilton produce similar lightweight clutch cylinders of very high quality. But with a very high price tag as well.

For my own use I have fitted and tested the Quinton Hazell clutch cylinder, part no. CSC 008, which is of the lightweight aluminum type, both on my former Lotus Elan Sprint and on my current Elise S1. In both cases the clutch pedal became lighter and the clutch grip point more consistent and well defined.

So here is a recipe for fitting the SAAB concentric clutch release cylinder to the Elise with Rover K-series engine and PG1 gearbox.

'''Threaded bolt holes'''

The clutch cylinder needs three M6 threaded mounting holes drilled into the gearbox clutch housing according to the drawing below.

[[File:The SAAB type flange dimensions.JPG]]

It’s advisable to mark up the dimensions on 2 mm steel sheet and thereby make yourself a drill pattern. The centre hole should be 35 mm for the centre spigot and the three holes providing for the M6 threads should be 5 mm.

With the help of a drill press machine drill through your sheet steel drill pattern and 15 mm into the gearbox clutch housing, put a 5 mm plug through the first drilled hole fixing the pattern plate and then advance to the next hole thereby precisely fixing the holes in relation to the centre and to each other. If you know somebody with access to a CNC machining centre it will be a quick operation but if you have the skills and patience you can manage fine with simpler tools.

The Ø 35 mm hollow centre spigot for the old release bearing is machined down to a length of 3 mm to accommodate the new clutch cylinder.

Before drilling:

[[File:Before drilling.JPG]]

After drilling:

[[File:After drilling.JPG]]

'''Clutch cylinder backplate'''

The clutch cylinder itself has to be disassembled.
The back plate is fixed by small deformations of the Ø 59 mm edge of the aluminum. These deformations should be carefully and gently tapped back with a blunt and rounded small chisel. You can then remove the back plate.

[[File:Original backplate removed.JPG]]

The original backplate is substituted by a fabricated one with the below dimensions to provide for centration of the clutch cylinder on the remaining Ø 35 mm spigot.

[[File:New backplate dimensions.JPG]]

[[File:New backplate ready for fitting.JPG]]

The new backplate is carefully fixed by tapping the edges of the aluminium over the 45º chamfer pointing to the rear.

From a M6 threaded bar 3 suitable long stud bolts are cut, carefully deburred and turned into the M6 threaded holes in the clutch housing. The clutch cylinder is placed over the centre spigot and over the stud bolts. The distance between the edges of the clutch housing and the clutch cylinder back flange is measured carefully. Three long M6 nuts are cut to exactly this length and fitted over the stud bolts to provide base for the fixation of the clutch cylinder.

Ideally the backplate should be in light tension when the nuts on the front side of the clutch cylinder are tightened. Then the forces are fed into the recess at the base of the cut-down
Ø 35 mm spigot and not through the three bolts.

***Hydraulics'''

The brake/clutch fluid activating the clutch cylinder will have to be routed through the clutch housing. A bleed line pass-through should also be provided for.

The clutch cylinder has no connection for a bleed line. It’s possible to remove a small steel ball blocking a drilling, cut a M6 thread in place and thereby establish a connection for a bleed line.

You can buy suitable fittings for passing through the clutch housing. Or you can ask somebody with a lathe to fabricate some for you.

[[File:Fitting.JPG]]

The holes for hydraulic fittings passing through the clutch housing should be drilled in places carefully selected with respect to the clutch pressure plate passing close by on the inside and to assure access form the outside as well.

[[File:Hydraulics connected.JPG]]

[[File:Hydraulics from outside.JPG]]

So with the above relatively simple and straightforward modifications and the relatively cheap SAAB clutch cylinder you can convert your PG1 gearbox to use a modern, light, simple, reliable and well-functioning concentric clutch release cylinder mechanism.

[[Category:Transmission]]
[[Category:Lotus Elise]]

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:26:46Z

EliseS1 man:

File:The SAAB type concentric clutch cylinder.jpg

2022-08-05T13:10:37Z

EliseS1 man:

File:Original backplate removed.jpg

2022-08-05T13:10:18Z

EliseS1 man:

File:New backplate ready for fitting.jpg

2022-08-05T13:09:51Z

EliseS1 man:

File:New backplate dimensions.jpg

2022-08-05T13:09:29Z

EliseS1 man:

File:Location of hydraulic fittings outside.jpg

2022-08-05T13:09:07Z

EliseS1 man:

File:Hydraulica connected.jpg

2022-08-05T13:08:45Z

EliseS1 man:

File:Flange dimensions.jpg

2022-08-05T13:08:24Z

EliseS1 man:

File:Fittings.jpg

2022-08-05T13:08:05Z

EliseS1 man:

File:Before drilling.jpg

2022-08-05T13:07:38Z

EliseS1 man:

File:After drilling clutch house.jpg

2022-08-05T13:06:52Z

EliseS1 man:

How to fit a concentric clutch cylinder to the Lotus/Rover Powertrain PG1 gearbox

2022-08-05T13:02:41Z

EliseS1 man: Created page with "'''Get a smooth and a well proven solution using a SAAB cylinder'''"

'''Get a smooth and a well proven solution using a SAAB cylinder'''

Toe alignment using straight edges

2020-04-19T20:26:40Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

The depth gauge of an electronic caliper can be used to measure distance from straight edge to rim fore and aft on the rim and the difference is the toe. You can even zero the caliper on the measurement fore and then you have the resulting toe when you measure aft on the rim.

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm in this case one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

[[Category:Suspension]]
[[Category:Lotus Elise]]
[[Category:S1]]

Toe alignment using straight edges

2020-04-19T20:24:49Z

EliseS1 man:

Toe alignment using straight edges

2020-04-18T22:01:30Z

EliseS1 man:

Toe alignment using straight edges

2020-04-18T21:41:05Z

EliseS1 man:

Toe alignment using straight edges

2020-04-18T21:39:26Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

The depth gauge of an electronic caliper can be used to measure distance from straight edge to rim fore and aft on the rim and the difference is the toe. You can even zero the caliper on the measurement fore and then you have the resulting toe when you measure aft on the rim.

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:37:56Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

The depth gauge of an electronic caliper can be used to measure distance from straight edge to rim fore and aft on the rim and the difference is the toe. You can even zero the caliper on the measurement fore and then you have the resulting toe when you measure aft on the rim.

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:35:19Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

The depth gauge of an electronic caliper can be used to measure distance from straight edge to rim fore and aft on the rim and the difference is the toe. You can even zero the caliper on the measurement fore and then you have the resulting toe when you measure aft on the rim.

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:33:05Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

The depth gauge of an electronic caliper can be used to measure distance from straight edge to rim fore and aft on the rim and the difference is the toe. You can even zero the caliper on the measurement fore and then you have the resulting toe when you measure aft on the rim.

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:25:32Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is this simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example but you can edit the numbers below with you cars requirements.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:23:24Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 and the 340R toe requirements are used in this example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:19:09Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of Lotus suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:18:24Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

# Two 4 meter long builders straight edges
# Four 5 liter sprinkler fluid bottles

And the setup is simple:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:14:55Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

In this case the car is set up with the 340R-settings for track use and they are according to the Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:11:47Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the grey ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:10:18Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the white ½ mm plastic foil between rear sidewall and straight edge used for checking gap.

[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.

Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:08:11Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

Note the white 4 mm plastic block between rear sidewall and straight edge used for checking gap.
[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

Note the white ½ mm plastic foil between rear sidewall and straight edge used for checking gap.
[[File:Toe_rear.jpg]]

Now the task of checking toe on wheels front and rear is reduced to putting two straight edges along the tyre sidewalls each side and measure gap from rearmost tyre wall to straight edge. So if one has a gap of front 3.9 to 4.1 mm and rear 0.5 to 0.8 mm one is good to go.

Tip 1: Pieces of plastic foil or plastic blocks used for supporting thermo glass in window frames are available in the required thicknesses and are handy and tyre friendly when measuring toe gaps.
Tip 2: Tyre side walls do not always run true. Repeat the gap measurements four times with the car pushed forward ¼ of a wheel revolution in between measurements and take the average of your readings.

Hope you will enjoy the described cheap and adequately precise geo tool!

Toe alignment using straight edges

2020-04-18T21:01:43Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

[[File:Front_left.jpg]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

[[File:Toe_rear.jpg]]

Toe alignment using straight edges

2020-04-18T20:56:56Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

[[File:Front_left.JPG]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm

[[File:Toe_rear.JPG]]

File:Toe rear.jpg

2020-04-18T20:55:41Z

EliseS1 man:

Toe alignment using straight edges

2020-04-18T20:54:58Z

EliseS1 man:

== A simple method for checking front and rear toe alignment ==
To enjoy the benefit of a Lotus' suspension and its cornering ability it is important that the wheels actually point in the direction that Lotus intended.

The "string method" for checking toe settings is well known and described in this forum.

However I have found that using straight edges can be a little easier to set up and handle if you add a few easy measurements and calculations.

What you will need are these simple tools:

1. Two 4 meter long builders straight edges

2. Four 5 liter sprinkler fluid bottles

And the setup is simple too, like this:

[[File:Straight_edge_left.jpg]] [[File:Straight_edge_right.jpg]]

The sprinkler bottles are placed up against each wheel. The straight edges are placed lying down on top of the sprinkler bottles and the straight edges touches the sidewall of the tyres.
The ends of the straight edges should overhang the front and the rear of the car.

Common 5 liter sprinkler fluid bottles are ideal as they are suitably heavy when filled with fluid, they are level on top and their height conveniently matches the center height of the wheels.

Any material for the straight edges can be used as long as they are straight and don’t bend. It is easy to check edges against one another; turn them round and recheck, they should not show any gaps or twists. Builders straight edges can be bought from builder’s material markets and there are lots to pick from on the internet. I used SVALK aluminum extrusions of 18 x 100 mm, but any sensible straight and stiff ones will do.

Placed against the tyre sidewalls the straight edges are not parallel and do actually toe-in a little.
So we will have to quantify the amount of toe-in of the straight edges which of course will be our references.

An Elise S1 is used as an example.

The distance between the straight edges front and rear is measured as well as the length of the straight edges.
From the drawing below you can see the measurements obtained from a car with standard rims and standard tyre dimensions.

[[File:Measuring_straight_edge_at_tyre_sides-komp.JPG]]

The amount of total toe-in of the straight edges can now be calculated to: 1883-1823=60 mm

[[File:Toe_triangle.JPG]]

So in relation to the car centerline each straight edge has an individual toe-in of: 60/2=30 mm

The toe-in of each straight edge can therefore be calculated to: 30/3998=1/133 mm ⁄ mm

This means that for every mm you go forward along the straight it goes inwards by 1/133 mm.

This is useful when we check the alignment with the straight edges against the requirements set up by Lotus for the toe of the rear and front wheels:

The 340R-settings for track use are according to Lotus service notes:

[[File:Lotus_rear_toe-komp.JPG]] [[File:Lotus_front_toe-komp.JPG]]

So we have

Rear: 2.5 mm toe-in each side; + 0.2, - 0 measured on a 16” rim.
Front: 0.5 mm toe-out overall; +0.2, - 0 measured on the 15” rim.

which translates to individual wheel settings of

Rear: From 2.5 mm to 2.7 mm toe-in each side measured on a 406 mm diameter rim.
Front: From 0.25 mm to 0.35 mm toe-out each side on a 381 mm diameter rim.

'''Toe measured on rim diameter:'''

Locally at each wheel rim we have this situation in relation to the straight edge each side:

[[File:Front_right_wheel_distance-komp.JPG]]

[[File:Right_rear_wheel_distance-komp.JPG]]

'''Toe measured on tyre wall diameter:'''

As the straight edges touch the tyre sidewalls front and rear it is convenient to reduce the task to check the gap from the tyre sidewall to the straight edge.
That requires a translation of the required distances measured at rim diameter to distance measured on tyre sidewall diameter:

Front:
Gap to straight edge measured on
rearmost sidewall of 485 mm diameter:
(3.1→3.2)∙485/381 = 3.9 → 4.1 mm

[[File:Front_left.JPG]]

Rear:
Gap to straight edge measured on rearmost sidewall of 510 mm diameter:
(0.4→0.6)∙510/406 = 0.5 → 0.8 mm