Originally Posted by TrackRat
The "optimal" pressure is TBD. A pyrometer is your friend if you're really interested in "optimal".
Typically you start 5-8 psi higher than BMW calls for an adjust according to the tires performance, your skills, the track, etc.
P.S. Have fun and stay hydrated with the hot temps!
thanks for the response. so 5 psi hgher? i would think keep standard as the tires heat up, no? so if its 35 then start with 40? what happens if they get up over 40, reduce heat betweens runs?