Re: straight pipe, x pipe or H pipe?
There are so many factors involved, it's almost impossible to say. With an X pipe, the only "tuning" factor you have is the location of the X (how far back from the headers), as that will determine your effective collecter length. With an H, not only do you have the distance from the header, but you also have the diameter and length of the H that will change the resonance frequency of the H, changing the behavior of it through the RPM range. If you have say a 3" diameter H pipe that is only 6-12" long, it will probably perform very similarly to an X pipe. If it is much smaller in diameter or longer, that's when the harmonics start to play a role, and the H could produce more power than the X in one RPM range, but less in others.
'97 F250HD 4x4 460; '85 Ranger, 350hp 289, T5, email@example.com
"If at first the idea is not absurd, then there is no hope for it.” Albert Einstein
Last edited by Motorhead; 03-28-2009 at 12:53 PM.