I would wait on those tires. they can mask some driving inconsistentcies. Just for giggles. the Sentra is able to consistently lap sebring (full course) in mid 2's on street tires, and we were only to be about 2 seconds a lap faster on full DOT tires. Loren used to drive the several seconds a lap quicker then me, however this last time I finally understood what he was talking about, and was much faster (
Plus I'm not afraid of looping the car) I would assume our lack of horsepower (we are NOT Much faster then a spec miata in a drag race) should put a Good Rx7 Lap (which is a GREAT track car) about 10 seconds faster regardless of the tires. (Sebring is very horsepower demanding) and takes a lot of laps to drive it as fast as it needs to be driven. turns 1 and 17 are fast 4th gear corners. a REAL race car is in the 1 min time and a GREAT race car can lap the 3.7 mile course in under a min

If you guys are turning 3:15 don't fix the car. get more experence! best thing you can spend money on.