Hey guys,

I'm going on a timed track session tomorrow with my 997TT and I was wondering if anyone could recommend the ideal tire pressures in PSI for my Pirelli Corsa's (same size as stock). I had a quick practice session today on the track using standard pressure settings (34 front 40 rear) and I didn't notice a huge difference in grip compared to my stock Rosso tires. I've heard some guys using even less than 30 psi on the fronts and close to 30 on the rears.

Can anyone give me a heads up about this? Is it safe to drive on the track with tire pressures that low? Obviously the pressure will increase with temperature increase, but what are the ideal numbers I should stick to??

Any help much appreciated! Preferably before tomorrow!

Thanks!

 

I tried my turbo on a track and to tell you the truth i didnt like it so much... Maybe because I have a tip version.. I found it very heavy car in short corners... start first with the stock psi you have in order to help the tires (not to destroy them) and then after you learn the track a little bit use less psi in order to have better grip...

Also I would recomend having more camber (i dont know how you call it in US in order to protect your tires) and having better grip also or else you are going to destroy them in no time from the out side of the wheel...
I am afraid 997tt is not the best car for track..

 

i am not sure, but i can tell you that if you do a search, that previous threads that were answered by some pretty knowledgeable people who were measuring tire pressures after doing some pretty aggreessive track work have recommended a significant decrease in tire pressure before running it on a track. if i remember correctly, i think it was an 8-10 decrease in psi.

 

Depends on the tires. For Hoosiers I run 34-38 pounds hot. I start at about 28-30 pounds cold

 

If you are heading to the Bahrain track; have one of the BMW performance guys help you out. You could run low and high and see what suits you the best (they have a very accurate gauge too).

 

Ok thanks guys

Yes I was at the Bahrain F1 circuit over the weekend..

I started out with stock pressures, then took them down to about 30 psi front and rear, which did help my lap time actually. I would say I improved by around 2-3 seconds after a few laps with the lower pressures so it does make a difference but of course tire wear suffers. I could probably use them for another track day at best.

I agree that the car is heavy in the corners, but I was wise enough to ask for an instructor session which helped my techniques and lap times. I'm sure I can shave off more seconds with more practice.

 

If you want to get more seat time on the Bahrain Track; I suggest you take the BMW Race professional course. Its a three day course in their Formula BMW FB2 cars; I shaved off over several seconds.

http://www.bmw-performance-bahrain.com/

 

The most accurate way to asses how much pressure to run is to measure the inside, middle, and outside thirds of each tire tread using a contact pyrometer - run about $100 or so. Do this on a hot lap and write down the numbers and compare on each tire. You want to bleed off air or add air so that the temps across the tires are as even as possible. Hotter in the middle = bleed off air. Hotter on the sides = add air.

 

I'm seriously considering taking their 3 day course, I've heard great things about it. Is it a full 3 days? If so, I'll have to find the right time and take time off just for this, but I'm sure it's worth the price they charge.

 

Interesting comment about air use depending on where the heat is (I never knew that).. I'll have to look for one of those tools for the next track day.

Anybody else familiar with this technique?