Rob 93ZR-1

Couldn't find help in any archives so, 275 40 17 all four corners w/ - 1 deg camber front, -.75 rear. Anyone have about this setup and what pressures are you running for autox or track?
Thanks in advance!

Vette Track Car

Rob,
I have run SCCA Solo1 and 2 on that exact tire and size for over a year on my 89 with a good bit of success. I usually run any where from 33/33 to 35/35 hot. I have since changed to 17 X 11's and 315 all the way around. With this set up I found the extra bit in the rear created a little push in the front so I dropped the fronts 3 pounds lower and it now hooks up well.

C4racing

For what it's worth, conventional wisdom suggests that you INCREASE front tire pressure to reduce push (understeer), especially for low speed events such as a Solo II. I know it sounds counter-intuitive, but it's true. You might want to try it next time you're on a Solo II course.....

(without getting into lots of theory, this does assume however that the tires are starting out at "street" pressures which are usually under the optimum pressure for maximum adhesion.....the optimum pressure being a complex function of cornering speed, suspension geometry, alignment settings, roll bar stiffness, shock settings, etc.) :crazy:

Buck96LT4

Rob 91Z07,

Here's the set up I run somewhat succesfully in autox with the 275/315 Kumho Victoracer V700's.

FRONT REAR

CAMBER L -1.7 R -1.6 L -1.5 R -1.6
CASTER L 5.0 R 5.1 0
TOE .25 .24

Air pressure is F38/R40.

Buck.

vettmike

We run the following air pressure on our '89 autocross car:

Front = 42 Cold

Rear = 38 Cold

We try maintain these pressure throughout the day.

With these setting we get good even wear and very predictable performance.