Trackday tyre pressures

[gazbutS3]

Doing Anglesey on Saturday, any got any ideas as a good starting point for tyre pressures, using pilot sports 3's in 225/40/18?????

[Top Cat]

Not much use now Gaz, but it is down to personal preference on handling characteristics. As you know the pressures go up the hotter the air gets, so it is best to adjust once warm not cold. Somewhere round the recommended cold tyre pressure should see you right. In my car they need dropping by about 4 Psi per corner, and usually a bit more on the outside tyres depending on the direction of the circuit. Dropping the pressures in mine reduces under steer, not sure on a front wheel car. You can also alter the pressures front to back, to reduce or increase oversteer. Again not sure in a front wheel drive car but I am guessing the principals will be the same.
A bit of trial and error throughout  the day should get you to what suits your driving style. Under steer is a bummer and hard to drive around, if your not getting to much of that then I would just not worry to much about pressures and just concentrate on enjoying yourself. 

[tony_danza]

I'd echo that, but road tyres can be a pig to set up, it's trial and error really.

What really helped was having them filled with nitrogen, much less fluctuation in pressure, thus easier to baseline.