You won't be able to tell much from my 60fts...they suck...the tires break loose a little as soon as I hit the transbrake...but I leave at anywhere between 7-10 PSI...1.55-1.58 60fts...I did manage to get a 1.51 with this combo leaving at around 10 PSI but haven't been able to do it again...track must have been prepared especially good when I did that...I'm currently working on some suspension changes to remedy the problem...I should be in the 1.4's...