i run on a carpet track here in s.d. it is 60X40 w/ one straight down the 60' side. ave lap times are about 9 to 9.25 sec. in stock sedan. i am gearing down to 22/72. tight enough? last weekend i ran a 76spur w/ a 23 pinion. the car was just a bit faster. it was noticable though! you may even try gearing down a tooth or change your spur to get the equiv of half a tooth change in ratio. sometimes the acceleration is more important than the top end, especially on a very tight track.