Its a bit subjective and not quite black & white. 225/40/18 - got some potenza s001s for a track day next week (usually run Uniroyals but they don't take well to a dry track) I've searched the meganeRS forums...I've read I should run higher for a track day...then I've read just run higher at the back for better turn in (so 29/32 as opposed to 32/29) Am I better to start high and work down or the other way around? Get a foot pump for the day and play with the pressures?
I dont think higher is right at all. The tyres will heat and the pressure will build. I was always told the rule of 2 2 bar pressure , then experiment from there
You will only need a foot pump at the end of the day to blow them back up , try and keep them all around 32-36 hot
Start like Andy and Steve say close to the handbook pressures and if you feel the car understeers too much then you can play with running the rear a bit higher the front a bit softer etc. Safest bet is always to just bleed down from book pressures to a similar hot pressure which should then stabilise for the rest of your sessions. Don't forget to check after lunch and potentially pump the tyres back up a bit. If at the end of the day if you have been taking more out of the tyres middle then you know you were running a touch too high and can use that as knowledge for next time but I doubt that will be the case as the cars don't run much camber. Keep the sessions short to avoid tyre shredding, seen it to many times where guys get carried away stay out sliding the car around for 40 minutes then wonder why they have shredded off the outside 2" on the tyres.
When I am on track, I have found the sweet spot to be around 25-26psi front and rear when the tyres are cold. Once warmed through they come up to 32-34psi. That said, it will depend on your tyres, the track temperature, your driving style, and even the track itself! IMO, the best idea is to leave them standard (maybe a bit lower) and go out and do a 2-3laps first. One warm-up, one hot, and then one cool down lap (for the engine/turbo). Then come back into the pits check the tyre pressures and drop psi until they are back to the standard pressures you like.
Wow thats alot! In Time Attack i run 24 cold on a warm day takes it up to around 31/32 psi, with mine any higher it effects the tyre too much
True and I/we found 29 psi hot just about perfect on the Porsche for either DZ03g or Cups but both cases mine and yours are track tyres on purpose built/setup track cars, I wouldn't run road tyres on a road car as low as that. (for ref the road tyre pressures on the Porsche are also 36 psi, its remarkable how consistent these things are across many cars except freaks like 911s).
Used to aim for 30psi hot with yoko ad08s on stripped out car.. If yours isn't stripped out or on standard suspension mabey little higher 32ish or you could end up rolling sidewall too much (mine used to on cup springs got a pic of slick off the bead through camp at combe somewhere) depends on tyre too ive never used potenza's. ive been using 28 front and 29 back on my Michelin slicks..( only staggard as its really easy to loose temp on rears of them)
