Z07coupe

I'm running a 90 coupe for track days, Superram 383 and lowered. Front: 91/2 x 17 wearing 275/40/17 V700 Victoracers. Rear: 11 x 17 wearing 315/35/17 Victoracers. My mistake last week was too much tire pressure resulting in lack of traction. Cold pressures were 37# F & R. (Outside temps were mid to high 40's). I have no experience in studying tire pressures. Now that the outside temps will be 70-95 degrees, where should I begin?
Tire Rack says hot tire temps between 35 and 40.
Kumho has no advice.
Forum members, from what I have found, start the front at 29#, and rear between 23# and 27#.
On a sunny 70 degree day, how much of a tire pressure increase am I looking at between cold and hot?
I will run primarily on technical tracks resulting in speeds maxing out at 115 mph.
Any assistance will be greatly appreciated.

Sidney004

I ran the Victoracers at 36 Hot Front, 34 Hot Rear. I cured the lack of traction on the Victoracers by switching to V710's, but those pressures should be in the ballpark. Measure and adjust them immediately after a session.

davidfarmer

10psi is a good guess for pressure gain, but it will vary depending on temperature, and the amount of moisture inside of your tires (from mounting "lube" and compressed wet air from tire shops tanks). After your first session, bleed them down if you overshot, then check them periodically.

If you have an OEM alignement, you may need a bit higher pressures to keep the outside edge from excessively wearing. Aggressive alignments allow you to run slightly less pressure.

Bill Dearborn

If the moisture level is bad enough it will seem like you cannot control the tire pressure. I had a V700 that kept increasing its pressure to 42 psi. This was after bleeding 2 lbs out 3 separate times. Finally we bled all of the air out of the tire and refilled it to get control of the pressure.

On my C5 I would get ~ 10 psi increase from cold to hot with the V700s.

Bill

Z07coupe

Thanks Guys,
I learned something from each of you. This weekend we will pay close attention to tires and pressures.