Hey guys just switched the radials off my Challenger and went back to the biasply slicks. I put ten passes on them Saturday during the bracket race but never really got them broke in. They are still smooth on 90% of the tire like it has never touched the track. They weren't hooking very good either as my 60' was off about .08 all day until the semi's where it picked up .04 in the 60'. My real question is, how can you tell if you have to much air pressure or not enough? I started off with 12psi, then 11, then 10 with no real changes in performance. The center of the tire still has the mold strip down it like it has never touched.