I run 30f/34r hot.

What do you run?

 

you are way underinflated for street driving...those are even low for track temps hot, which are around 36-38f/38-40r

 

Been doing 30/33 (cold) and like it.......taking me to 33/36 warm........ obivously a tad more when more spirited.

 

32/35 cold.

 

why not set to what the owner's manual recommends? tire pressure is supposed to set when cold. I don't recall seeing one tire pressure for street and one for track. thoughts?

 

track pressures are totally different than for the street...agressive track driving will raise the cold pressure 8 to 10 pounds and when street tires get around 40 psi hot they lose grip so cold pressures for the track start out underinflated to allow for 8-10 pounds increase...there is nothing wrong with using the recommended cold pressures for street driving because unless you are Jeremy Clarkson spirited driving is unlikely to exceed 40psi

 

ok good to know. makes sense.

 

so then if you are running the factory street tire, what pressure do you recommend for the track

 

starting cold track pressures will depend on the track conditions/ambient temperature and your driving style...also depends on your experience level because when you first start out you won't be putting that much heat into your tires...if it was a normal day with 70deg temps I would start out in the morning with 28-30f and 30-32r and run 4 or 5 laps and come into the pit and check pressures and go from there..should give you a good baseline...finish the session and check them again as soon as you pit and drop them to your desired hot pressure if they exceed your target..best to not exceed 38-39f and 39-40r hot...check again after each session and adjust if necessary

 

+1.. Sounds like the most sense to me.

 

I use the pressures stated in my Porsche owners manual. If I remember correctly for the RS its (cold) 29 front 33 rear. There is a label somewhere on the door frame that clearly states it. 30f/34r hot seems too low but without knowing the ambient conditions, etc, impossible for me to judge. That's why cold starting pressures are typically used as the starting point for reference.

For the MPSC and my RS, with a nitrogen fill, I start cold with 29f/31r and adjust from there. With compressed air fill I start lower, usually 28f/28r. I try to end up at 34-36f/38-39r (definitely below 40) with my set up. There are a lot of variables but those are reasonable reference points as stated by others.

 

great info guys

thank you so much

 

I thought stock pressures for GT3 cold are 33 front 39 rear...no?

 

For my 2007 GT3 the factory recommended pressures (as shown on the label inside the driver's door) are 29F and 33R.
My car came with the Pirelli P-Zero Corsa's.
Mr. B

 

Thanks! interesting in that a Carrera S with the same size tires the factory pressure is 33/39 except for the 2009-10 997S it's 34/40.....

wonder why the vast difference in factory pressures?