I have an camaro z-28 m6 baisly stock and am having problems with quarter times. All I have is a K&n air filter and am waiting for my slp lid. I have the ls1. It is to be said that the ls1 f-body can run 13.5's bone stock. Well I didnt even brake into the 13's. My best run was 14.071 @102.96 My Reac time was .0778. I think its my launch What is a good rpm for the launch. Im letting out at about 1800RPM's. I wasnt to happy with my et at all. I even have the hurst short throw factory option I dont know what the deal is.