When i had zpt w rated tires i could take it up to 5000 rpms and drop the clutch and get a good launch. But with my z rated tires now i can only take it to about 4350 before i drop it. It also helps to drag the clutch out...burns the hell out of it but it works. I raced a 240 the other day from a stop and got a better launch then him and he has rwd.