C6 Rake
 

I have a 2005 C6 Z51 and I'm getting CCW Classic wheels & Hoosier A6s for autocross.

Q #1) I'm considering going with same size tire 315x30x18 all around. Will my computer protest in Competition Mode or even with the AH/TC OFF?

Q #2) If no protest from the computer, will the car do better from a handling standpoint with some rake. (Hoosier 285x30x18 F and 315x30x18 R which would be a 1" larger R diameter. The car comes with 1.2" larger diameter stock.)

THANKS for your input. Norm

I haven't researched the trouble codes, but in the C5's, it would have to be off much more than that to cause a problem (9mph diff to cause an error). I think you'll be fine.

I would leave the rake as is, then adjust the rear as needed to add/remove oversteer. The rear will drop relative 1/2", but the suspension will remain in the propper motion range. If too much oversteer, drop the rear a little, too much understeer, raise the rear a little.


**just looked in the manual, I think you'll be fine on the change of tire size. Don't forget the pressure sensor issues...

With 4 tires of equal diameter I was a little concerned that the computer would see that as the rear having some wheelspin (faster rotation relative to stock) in competition mode when cornering.

I was talking to Luke @ TireRack & he said he has heard from reputable racing guys that even with AH/TC completely turned OFF that the computer will still intevene in extreme situations. ? He's heard of major attemps to completely disable the system of those interventions but unsuccessful so far.

I've heard that the C6s like some rake ... I just hate to give up the width of the front tires in order to have the rake. I'm just not sure which is better / worse ... narrower tires in F to keep the rake or wider tires in F with same diameter as rear but no rake.

THANKS for your input, David.

Norm

PS I've read everything on TP sensors and there seems to be conflicting info so I still am not sure what to expect. I plan to use these wheels for autox and stock wheels for track days so it may not be much of an issue with the short autox distances.