Yeah, that is a 2-3 year old post. Jim, if I discounted every old post I might not have the 70mm SC pulley that I do have and love. I'm going to throw this fellows response into my mix of info that will take me about 2 months to make a final decision. I believe an X-pipe makes more power than an H-pipe also, something else to confirm. I datalogged 20.6 PSI this morning and of course higher boost across the rpm range so more exhaust gasses to get out of the motor and exhaust system. Just about 50% more than stock. 42% to be exact, still a bit more spent gasses to expel. Again, a start of 60 days of research and interviews when possible! Mark