Chassis and suspension setup

ARRC can offer a full range of setup services for all kinds of cars although the most common are shown below. All these examples are for front suspension but could equally be applied to independent rears.

Front wheel camber


Basic setup such as ride height can be done with nothing more than a level surface and a ruler but some items of equipment make subsequent adjustments easier. The first of these is a camber gauge.

Set against the bulge of the tyre the small dial at the bottom is turned until the bubble in the level is between two lines and the camber can be read directly. Adjustment maybe by shims in the suspension mounts, spherical joints in the suspension or by bending the axle if it's a beam.
 

Front wheel castor


A more complex adjustment and a more complex piece of kit.

First the wheel is turned to 20 degrees lock in one direction and the castor dial set to zero with the bubble between two lines.

 

Then the wheel is turned to 20 degrees on the opposite lock. The dial is re-adjusted to put the bubble between the lines again and the castor can be read directly. Once again this can be adjusted by shims or links.

It's often the case that these two adjustments have to be repeated as few suspension setups allow them to be changed independently.

Tracking


We use a traditional optical instrument for tracking.

This has two frames which are set against the wheels.
The desired toe-in or toe-out is set on a dial .....

.... and the steering adjusted until the viewfinder sees the mirror image in the correct position.

In a very few cases castor and camber may need to re-adjusted after tracking and then the tracking adjustment fine tuned.

Corner Weights


A final adjustment might be for corner weights, either to allow for the driver or to add pre-load. The use of four linked scales makes this job relatively easy although some suspension setups don't really allow for any adjustment.

For drag racing in particular four-link setup is greatly aided by use of a CAE package to compute the optimum arrangement.

Date  25-Oct-2011
Pictures by

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