Geo Setups: Difference between revisions

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2. If you dont have the S1 or S2 service manual suspension sections you really should get them as this is only a small part; http://www.sandsmuseum.com/cars/elise/experience/maintenance/alignment/alignment.html  
2. If you dont have the S1 or S2 service manual suspension sections you really should get them as this is only a small part; http://www.sandsmuseum.com/cars/elise/experience/maintenance/alignment/alignment.html  


3. Set the front castor by "shuffeling washers"
3. Set the front castor by "shuffeling washers" on the top wishbone pivots.


4. Set the front and rear camber by adding & removing shims (removing a 1mm shim plate will alter camber by approximately -0.25° at the front and -0.30° at the rear).
4. Set the front and rear camber by adding & removing shims (removing a 1mm shim plate will alter camber by approximately -0.25° at the front and -0.30° at the rear).

Revision as of 19:00, 24 August 2006

Some standard Geo settings

Geometry Standard S1 & S2 S2 135R 340R Road 340R Track
Ride Height F/R 130/130mm 120/120mm 100/110mm 100/110mm
Steering axis inclination 12° 12° 12° 12°
Front Castor +3.8° +3.7° +3.8° +3.8°
Front Camber -0.1° -0.5°  -1.8° 
Front alignment/toe 0.2mm OUT Overall 0 mm 0.2mm OUT overall 0.5mm OUT overall
Rear Camber -1.8° -1.8° -2.0°  -2.7° 
Rear alignment/toe 1.2mm IN each side 1.2mm IN each side 1.5mm IN each side 2.5mm IN each side
Bump Steer 2.0° to 2.5° toe in

converting from mm to degrees; divide the toe in mm by the wheel rim diameter in mm then ARC SIN the answer

Geo setting X does Y

Some guidlines although its dependent on many, many other factors

Increasing front camber from the default -0.1° to -0.5° each side will dramatically improve the understeer although the inside edges of the tyres will wear slightly faster.

Increasing rear camber from the default -1.8° to -2.0° (or higher) makes the car more neutral after you've removed the understeer.

Increasing front toe helps with the sharpness of the turn-in

Increasing rear toe cancells out the rear suspension flex when the tyre is loaded which leads to toe out - so running more toe in compensates for that - you don't want toe out at the rear.

Setting your own geo

Whilst a race prep specialist can charge £200 for a Geo you can DIY castor, camber and toe settings.

1. To baseline your current setup www.alignmycar.co.uk will find a local place with a Hunter alignment system who will provide a setup sheet showing castor, camber and toe for £15

2. If you dont have the S1 or S2 service manual suspension sections you really should get them as this is only a small part; http://www.sandsmuseum.com/cars/elise/experience/maintenance/alignment/alignment.html

3. Set the front castor by "shuffeling washers" on the top wishbone pivots.

4. Set the front and rear camber by adding & removing shims (removing a 1mm shim plate will alter camber by approximately -0.25° at the front and -0.30° at the rear).

5. You could set the toe yourself, but since a quarter turn of the track rod alters toe by 2mm its a damned delicate affair without a real time readout.

6. Back to the alignment centre to check your config for another £15 and set your front and rear toe for another £30. You can now alter the camber without materially affecting toe.

MEMO: Someone else can explain how to set bump steer !