JTRANTHA

The first track day i took my vette out with a new set of Kuhmo XS tires. since i was not sure what tire pressure to start with, i started at 34 or so. Then, once i was on the 2nd or 3rd lap, the tire pressure had jumped all the way to 41 degrees. I played with the pressure settings and ended up with a starting point of 25 or so cold.

Then, last month at Infineon, I was going to play with pressures a bit since I did not remember what I had started with last time, I asked an instructor and he said start at 33. Once i got the tires warm, the pressure shot up to 41, the TPMS sensors went off and the car was sliding all over. So, my method seems best but many disagree. (forums, etc)
Should I just stick to what I have been doing since it seems to be working.

I welcome your thoughts.

Thanks, Jason

sgsvette

Start cold 30 front, 29 rear. If pressures rise above 38 hot, bleed down to 38 and remember how many pounds you took out. When starting cold again, start with your new pressure settings.
Before someone other than a Kumho disagrees (and I know someone will), they should know our Corvette school was sponsored by Kumho for 5 long years and we specifically used the XS tire. 12 Corvette's running all day non stop with XS's. Guess where they got their feedback from?

hungryhippo

I start at 27 or 28 cold depending on the weather. Any higher and the car feels sketchy and the abs comes on easily.

TKOGTO

My fronts heat up more than the rears so I have been using 30/32 cold. I figure, right or wrong, the car has a fair amount of understeer built into the stock set up so I make this feeble attempt to dial some of it out.
My goals are to keep the tires from getting greasy and keep some semblance of balance. So far, it's worked well. On avg over 9 days, the psi's end up @ 35.5 LF, 34.7 RF, 35.8 LR and 34.5 RR back in the paddock after a cool down lap (max temps have been 40,39,39,38 respectively). I usually have to bleed a lb or 2 before the 2nd session but rarely in subsequent ones. They usually settle close enough for gov't work to where I want them without adjustment for sessions 2 - 4. Even when the ambient goes up and I am driving harder, the max psi's get lower as the day goes on. I like that.
If it is real hot @ NJMP on Monday, I will start 2lbs lower all around in sessions 1 and 2 and take it from there.

ipuig

stevensa

The real question is, where did you find XS's in stock at?