when you pull that resonator off you will see that it's not your typical resonator. it's big, heavy and there is lots of resistance. all i'm running on my svt is stock piping, with no mufflers, and a glass pack where the resonator was. i couldn't tell you for sure what kind of H.P. differance it made. it seemed to help out my top-end, plus it's a very distictive sound that i have yet to hear any other car make in sa diego.
