I did some searching but couldn't find anything "conclusive" enough to make me happy.
My car is going in for a cam swap and to get the 2-3 not shift at WOT fixed. We are going to do some dyno testing with my exhaust on the engine dyno, from my headers & my exhaust all the way back.
The guy who runs the shop tried to get me to go with spin techs and and x pipe and my first reaction was loud and yuck, I've never heard an x-pipe so no deal.
Then I said I like my big hemi super turbo mufflers, because they are quiet. I was considering adding an H pipe for a little more quiet and a little more power. But here is the question-- is the H pipe going to kill the exhaust pulses from each tailpipe? If so, what are we talking at the 1/4 mile track here? a tenth?
I love that pop from each 3" tailpipe, and if the H means thats gonna go, I may decide not to. I have a 3mb .mov of my car idling for 10 or 15 seconds, but I don't know where I would host it. I bought webspace and a domain name, but its gonna take me a few weeks to get that worked out, I don't have time to fiddle with it right now.

Its a 2" primary, 3" exhaust all the way w/ 20" case dynomax hemi super turbos on it, behind a 550+ hp 460, which should be 625+ when the solid roller gets in.

thanks.

i think x-pipes are more mild sounding then h pipes.

i have turbos and an "H" pipe on mine and it still sounds nice at idle, it still has that lumpy cam sound

Jim Hand did some testing with his car and found the x-pipe to be worth about .15 seconds in the quarter over the h-pipe. There was another test on a 10-second Olds that showed the pipe to be as fast as open headers, and a tenth and three mph over mufflers and an h-pipe. A tenth of a second at 130 mph is about a car length. There is probably a larger differential using true dual pipes.

http://www.boyleworks.com/ta400/psp/exhaust.html

http://www.timskelton.com/valkyrie/tech/images/h_pipes.pdf

answered own question-- found some sound clips.

Matt

Matt, too bad you couldn;t make it up to Lebanon last year. I run the X with 3,5" headpieps and 3" Magnaflows that are probably identical to your STs. You could have heard your system with a X pipe. With quiet muflers, the " Xsound " is very subdued.