Tire presure for superformance on street

[LENSJADE]

HEY OWNERS WHAT FEELS GOOD I HAVE A SUPERFORMANCE WITH SMALL BLOCK HAVE MICH PILOTS IN FRONT AND REAR 270/40/17 FRONT 335/35/17 REAR WHATS A GOOD TIRE PRESURE FOR STREET DRIVEING AND SOME BACK ROADS THANKS

LEN

[vatdevil]

For street, 18 psi works best for me. 24 for autocross.

[Sawdust]

I run 18lbs front & rear with no problems.

Stu.

[jhv48]

I run 22.5 pounds both front and rear.

For you guys running 18 pounds, don't you notice flat spots after the car has been parked for a week or two on cold concrete? Front end shakes like they are out of balance? My Kumhos take about 5 miles of driving to smooth out after a week on cold concrete. In the summer, they smooth out after a mile or so.

[Sawdust]

I have never noticed flat spots or front end shakes

[madmaxx]

another question is does pressure very based on tire size, is 15" tires take same pressure as 17" tires

[vatdevil]

I use chalk or other means to mark the tire, then drive normally to verify complete tread contact. Keep lowering pressure until full contact. Do the same process when auto crossing. Running 275 and 315s on 18 inch rims.

[scootter]

I have the same 17" tires on my Superformance. 335 rears and 270 fronts. I run 24 PSI front and rear.
Scott

[289fia_cobra]

The "general" rule I've used is 1-PSI for every 100 lbs. But the chalk method tends to be a good method during autocross since you have to adjust your psi's just before every run and usually start off higher than street.

For street, since I corner weighted my FFR to 2500 lbs ( 2496 officially but I gained 10 pounds since!) I set my pressure to 25psi front and rear.