race setup - total toe or toe per side?
 

dave darling's notes:

Sticky tires, 220# springs/21mm torsions/22mm front sway bar, track w/some autoX:
-2.0 deg camber F
-3.0 deg camber R
~1/16 inch toe-OUT front
~1/16 inch toe-IN rear

Would that be 1/16" toe per side or 1/16" to total?

Also, wouldn't 1/8" toe in at the rear be better for a racecar with the above specs?

thanks,
dr

Total. Measuring the front toe per side is close to (but not completely) meaningless. For the rear, each side would get half that.

For a race car, though, you really need to get a pyrometer to be able to set the alignment and tire pressures accurately. The above are "general hints"--everyone's car and driving style is different, and you can get lower lap times by departing significantly from the suggestions above in some or many cases.

--DD

I recently took ulf to the track. My alignment specs are 1/16 toe, front and rear & -2 deg camber both ends.

At approx 100 mph the back end of the car started moving around...a bunch:eek: This was not under brakeing....straight line acceleration. I *suspect* it is a combination of rear lift and too little toe at that end. As the rear lifts, the toe decreases. Braking will also cause this....rear lift +braking forces pulling the toe out.
Oddly enough, I didn't have braking stability problems when close to the *nasty* speed zone....that has me a bit confused.
Needless to say, before I take the car to the track again, I'll be digging into the rear suspension. There may be something else going on there.

As far as camber is concerned, it's a matter of what your tires like. Both Rspec Kumhos & Hoosiers like some negative camber.
*On my car* -2 at the rear is too much. The insides of the tires are getting hotter than the outsides. The front seems to be spot on.

This shows you why you really do need a pyrometer! The "general hints" are not correct in all cases! Frankly, they're probably wrong at least as often as they're right, in one particular or more.

If you're serious, get yourself a pyrometer and learn how to use it and interpret the readings!

--DD

thanks david,

I was just looking for a baseline setup. We have only run the car once since we finished the chassis.

Will check the temps at the track this weekend.

thanks,
dr