Track day tyre pressure
Discussion
Drive there on road pressures, lower to 30psi all round when there, check after 1st session aim for 35 hot tops.
Have fun.
End of day pump back up to road pressures- v important will wreck tyres if you don't.
If you track on road recomended pressures in a 911 its horrible, rears will be well over 50psi & skitty as hell.
Have fun.
End of day pump back up to road pressures- v important will wreck tyres if you don't.
If you track on road recomended pressures in a 911 its horrible, rears will be well over 50psi & skitty as hell.
There's no set answer to this - it depends on the tyres and the construction of the sidewall. Putting them down isn't necessarily the correct thing to do, as you may not have enough pressure to support the sidewall, which could fold and well that wouldn't be good would it. Is it R888s or Yoko A048s or another semi-slick track tyre?
If not, I'd suggest starting on standard cold pressures, then do your first session, when you come back try lowering them back to road pressures and go back out. You could then try dropping and then perhaps increasing by about 3 psi and see which feels the best.
If not, I'd suggest starting on standard cold pressures, then do your first session, when you come back try lowering them back to road pressures and go back out. You could then try dropping and then perhaps increasing by about 3 psi and see which feels the best.
I used to track the 996GT3 on PS2s before I moved on to cups. Once geo-ed I found that when hot they needed to be only around 1.5psi lower on the fronts and 2.5psi on the rears below the recommended cold road pressures. I wouldn't go much lower as the sidewalls aren't really stiff enough for it in the way that track rubber is. Before the geo that still had them rolling a bit far over the shoulders (i.e. you will eventually bin them because you have worn out the shoulders long before going down the centre tread depth). That said - until you start carrying some proper speed they are a reasonable compromise and are great in the wet once up to track temperature.
I would warn against dropping hot pressures below cold road pressures for track work. This could lead to excessive side wall movement during cornering - I have witnessed a car pull the tyre off the rim mid corner due to low pressures - it caused the car to flip when the rim dug into the tarmac!
I would suggest starting with standard pressures, do a few laps, then check with your hand across the tread of each tyre. If the edges are much hotter than the centre, increase the pressure a few psi, if the centre is hotter, drop the pressure.
Also, try to monitor how the car feels when you are driving - road tyres can over-heat and lose grip - the car will start to feel loose. Avoiding this will mean you don't go home with a ruined set of tyres.
I would suggest starting with standard pressures, do a few laps, then check with your hand across the tread of each tyre. If the edges are much hotter than the centre, increase the pressure a few psi, if the centre is hotter, drop the pressure.
Also, try to monitor how the car feels when you are driving - road tyres can over-heat and lose grip - the car will start to feel loose. Avoiding this will mean you don't go home with a ruined set of tyres.
Cheers guys,
I'll be taking a small compressor so i'll play around with the pressures, its my 1st track in this car (ive only done 2 other tracks) and from experience, I feel i'm pushing the car to the limits but once Ive had instruction it becomes very clear in actual fact im just dawdling around,
so probably wont be doing too much damage to the tyres anyway. I just thought if theres a difinative answer #i'd do it.
Cant wait, only 2 weeks
I'll be taking a small compressor so i'll play around with the pressures, its my 1st track in this car (ive only done 2 other tracks) and from experience, I feel i'm pushing the car to the limits but once Ive had instruction it becomes very clear in actual fact im just dawdling around,
so probably wont be doing too much damage to the tyres anyway. I just thought if theres a difinative answer #i'd do it. Cant wait, only 2 weeks
checkmate91 said:
I thought you raised the pressures in road tyres for track work, not reduce them. Anyway this has worked for me (FWD) using Conti SC5...
Generally yes, but I found that on a 911 the recommended cold pressures were very conservative and a pound or 2 below worked well for both performance and longevity. Note that due to the tyre width, having the tyres over pressure is the greater danger. This distorts the contact patch and rapidly causes the centre of the tread to overheat. If the rears get above about 44psi on track then the majority of your grip vanishes almost immediately...Just in my experience of PS2s on track of course
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