What PSI Your Tyres Are

[Muzz]

The reason we run higher Psi on the tyres on the track or twisties is to strengthen the sidewalls due to the stress when doing hard cornering..

The general rule is to leave like a 25% window, say a tyre's maximum Psi load is 60Psi, the 25% window will be 45 - 60 Psi... So that 15 Psi range is where you will experiment and find out which Psi in that range will allow you to perform at it's best.. After that, you fine tune it to like 1-2 Psi range... Takes some work but heck, it's good for cars with no suspension mods!

id have to disagree, you obviously dont want the tyre to be rolling/folding over during hard cornering, but once your above the tyre pressure that keeps the tyre in correct formation, adding more pressure isnt going to magicaly improve performance/grip of the tyre.

You will greatly reduce the area of the contact patch, which isnt worth the trade off for less sidewall flex, which isnt always a desirable thing in road racing anyways. You will also overwork the centre of the tyres tread.

Dont use some extremly poor rule of thumb, that seems to work against the recomended tyre pressures of most tyres, use the manurfactures actual info for the tyre.

ie, Toyo RA1

Air Pressures Recomendations:
Dry Conditions
Front Drive - Starting minimum 24 psi.
Rear Drive - Starting minimum 18 psi.
Goal - 41 to 43 psi (hot)
Wet: (heavy water layer)
Front Drive - Starting minimum 28-30 psi.
Rear Drive - Starting minimum 22-24 psi.

Front Drive - Starting minimum 18-20 psi.
Rear Drive - Starting minimum 12-14 psi.

To pump your tyres up to 45-60psi cold, and only play around in that range is crazy, track car or street car. If you want less sidewall flex use a tyre with stiffer sidewalls.

http://www.tirerack.com/about/techcenter.jsp the first 5 links are reguarding tyre pressures.