I also run the jp's I have a jp4 on my v spec and I get great mileage, but the top end is a little lite. What I was after was a break down on each pipe and what each one was suppose to do. Like how the dynamite pipe's are set up the 007 is high speed and so on. Or even a list that gives cross reference of numbers like the os 2060 is close to the same as a ???