Camber/Toe/Caster settings for Atuocross

[Forester12]

Hi All,

What are people using for their alignment settings for Autocross?

I have a 1988 951 with 300# front springs and newer koni's on all 4s.

Using Toyo R888R's
255/35/18 front
275/35/18 rear

thanks !

[cda951]

Hi,

Due to the unfortunate camber gain characteristics of the 944's MacPherson strut front suspension, a lot of static negative camber is needed to keep the car from understeering in tight autocross situations and for track events.

Have you refreshed any of the front or rear suspension bushings? How are the front ball joints? These are a weak point on the later 944 aluminum front control arms, especially if the front suspension is lowered too much. For this reason, many PCA auto-X and DE tech forms stipulate a minimum 944 spindle to top of wheel arch measurement.

And you have 300# front springs with stock rear torsion bars? If so, this would be a big mismatch in front and rear spring rates, which will probably lead to understeer not matter what your alignment settings are.

Sorry for all the questions, but this is good information to consider rather than throwing out some arbitrary alignment settings without context.

In any case, if this is a dedicated auto-X car, I would run at least -2.5 degrees camber in front, if not more. A lot of auto-X people like to run a slight amount of front toe-out to improve turn-in, but this will make the front end feel darty on the road, and will accelerate inner edge tire wear, more so than excessive negative camber.

Here are my settings for my 951, which used to see a lot of track time. Has Ground Control coilovers with 500#F/750#R, all spherical suspension bushings, and also has modified front spindles to correct the front roll center for how low the front ride height is (not necessary if you don't go lower than 968 M030 "RoW" specs per the factory manual).

Front:

Camber: -3.0 degrees
Caster: max, which is around 3.2-3.3 degrees on my car.
Toe: zero

Rear:

Camber: -2.5 degrees
Toe: about 0.10 degrees toe-in per side, you need much more with factory rubber trailing arm bushings, more like 0.25 degrees per side!

Hope this helps!

[Forester12]

Thank you very much!