Unless you are highly modded, changing from a good hi flow cat setup to an off road pipe will not make much, if any noticeable difference in power and will usually kill some low end torque. This has been proven in many magazine tests and I have proven it to myself on my own car as I went back to a set of hi flows last year after running an off road pipe for about a year and a half. With the cats the car definitely has more low end snap and is slightly quicker in the 1/4. Also around here the penalty for getting caught without cats is severe - cases of $5,000+ fines for removal of emission equipment have happened and to me, its just not worth the risk of getting caught.
------------------
1965 K code coupe - numbers matching - restoration ongoing. 1987 LX notch, 5 spd, stock heads (minor porting) and intake, 65mmTB, 3.55's, ram air, pulleys, shorty's, 2.5" exhaust with cats 13.89@100.25
|