Hi all,

I race my '12 MCS hardtop in D-Stock. It is completely stock, but does have the sport suspension, shocks, and swaybar.

My question is this: I have the crappy ContiProContact SSR all-season runflats, in 205-45-17. Door sticker says to run them around 38.

If I want maximum handling capability/traction, what pressure should I set them to? Stock pressure? Overinflate? Underinflate?

Thanks.

 

For normal tires you'd add 6-11 pounds. For run-flats I haven't a clue.

Mark the edge of the treads with chalk or white shoe polish to make sure the tires aren't rolling over onto the sidewalls with too little pressure. Determination of the best pressure requires a pyrometer or a whole lot of testing.

As a point of interest, the answers for optimum handling and traction are different. Lower pressures give you better grip during acceleration while higher pressures give you better handling. Better handling trumps better acceleration with an experienced driver. Or at least that is so for normal tires.

Pump the pressures up a bit and enjoy yourself.

 

From what I understand the runflats will do better with some extra pressure. I would bump the pressure by the amounts hsautocrosser suggests.

I would also change the camber by pulling the white plastic plug on the top of the front strut tower and move the strut in by the amount the slots in the tower allow and then reset the toe-in. This is all legal in stock class.

Enjoy

 

Thanks. I will increase the pressure slightly. The biggest problem I've had is trying to accelerate uphill while in a sweeper. Despite trying to be easy on the throttle, I just spin my tires the entire time.

 

The run flats don't have the traction that an extreme performance tire has and wheel spin will be an issue. Does your car have DTC; are you spinning just one wheel?