c4danc

Okay so here is my story. I have been autocrossing my stock C4 vette for about a year now. i was on the stock rims and kuhmo ecsta spt tires. I finally have money to upgrade my car. i recently borrowed a friends camaro rims that suprisingly fit well on my vette. i was running 17X 9.5 on the front and 17X 11 on the backs. I also took all the shims out of the front upper a arm for traction. With this combo i was able to get a large improvement on the way the front tires grip. However, I now have a huge ammount of oversteer. I spin out at half throttle in a corner which has never happened before.

I know that there are guys running 17x11s on all 4 corners. what backspacing do you need to run those rims? Also what should my allingment be front and rear? Was i wrong to pull out all those shims?

StealthLT4

50mm offset (Grand Sport) is needed for 17x11 on all 4 corners. I forget the backspacing of that combo, but you can figure it out. Alignment will depend on several factors, but count on as much negative camber as you can possibly get on the front, and about -1.5* in the rear to start out with. Some slight toe out in the front can help with turn-in if it's a dedicated AutoX car (don't do that on a street car...), with slight toe-in in the rear.

Check out this chart for more info, and more setups: http://www.vbandp.com/instructions/h...ruct/align.htm

vincent ashton

I have also run the ZR1 offset on all fours with no problems.

worldsaway

My '87 C4 has kumho V710 295/17" front/315/18" rear on C5 wheels. I'll be switching to 18" fronts as soon as these wear out. If you can find C5 magnesiums they lightweight without costing like CCW's. My C4 has mild understeer, and I'd rather have mild oversteer. I think going with the square tire setup (315 f/r) is gonna give more grip up front. It'll fix my understeer, I don't think it's gonna help your oversteer. Ed

BrianCunningham

OP what class/club are you running in/with?