Geo Setups

2006-08-24T17:58:23Z

SteveB: /* Some standard Geo settings */

== Some standard Geo settings ==

<table x:str border=0 cellpadding=0 cellspacing=0 width=655 style='border-collapse:
collapse;table-layout:fixed;width:493pt'>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl24 width=158 style='height:12.75pt;width:119pt'>Geometry</td>
<td class=xl25 width=122 style='width:92pt'>Standard S1 & S2</td>
<td class=xl25 width=125 style='width:94pt'>S2 135R</td>
<td class=xl25 width=125 style='width:94pt'>340R Road</td>
<td class=xl25 width=125 style='width:94pt'>340R Track</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Ride Height F/R</td>
<td class=xl27>130/130mm</td>
<td class=xl27>120/120mm</td>
<td class=xl27>100/110mm</td>
<td class=xl27>100/110mm</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Steering axis inclination</td>
<td class=xl27>12°</td>
<td class=xl27>12°</td>
<td class=xl27>12°</td>
<td class=xl27>12°</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Front Castor</td>
<td class=xl27 x:str="'+3.8°">+3.8°</td>
<td class=xl27 x:str="'+3.7°">+3.7°</td>
<td class=xl27 x:str="'+3.8°">+3.8°</td>
<td class=xl27 x:str="'+3.8°">+3.8°</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Front Camber</td>
<td class=xl27 x:str="'-0.1°">-0.1°</td>
<td class=xl27>0°</td>
<td class=xl27 x:str="-0.5° ">-0.5° </td>
<td class=xl27 x:str="'-1.8° ">-1.8° </td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Front alignment/toe</td>
<td class=xl27 x:str="'0.2mm OUT Overall">0.2mm OUT Overall</td>
<td class=xl27>0 mm</td>
<td class=xl27>0.2mm OUT overall</td>
<td class=xl27>0.5mm OUT overall</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Rear Camber</td>
<td class=xl27 x:str="'-1.8°">-1.8°</td>
<td class=xl27 x:str="'-1.8°">-1.8°</td>
<td class=xl27 x:str="'-2.0° ">-2.0° </td>
<td class=xl27 x:str="'-2.7° ">-2.7° </td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Rear alignment/toe</td>
<td class=xl27 x:str="'1.2mm IN Overall">1.2mm IN each side</td>
<td class=xl27>1.2mm IN each side</td>
<td class=xl27>1.5mm IN each side</td>
<td class=xl27>2.5mm IN each side</td>
</tr>
<tr height=17 style='height:12.75pt'>
<td height=17 class=xl26 style='height:12.75pt'>Bump Steer</td>
<td class=xl27></td>
<td class=xl27>2.0° to 2.5° toe in</td>
<td class=xl28></td>
<td class=xl27></td>
</tr>
<tr height=0 style='display:none'>
<td width=158 style='width:119pt'></td>
<td width=122 style='width:92pt'></td>
<td width=125 style='width:94pt'></td>
<td width=125 style='width:94pt'></td>
<td width=125 style='width:94pt'></td>
</tr>
</table>
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 privide a setup sheet showing Castor, camber and toe for £15

If you dont have the S1 or S2 service manaual 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. Set the front castor by "counting washers"

3. 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. 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.

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Geo Setups