6.0, Dual in dual out or two singles?

[Carson92]

Trying to decide on mufflers for my 2500HD. Definitely decided on Magnaflow, but can't decide between two styles. There's dual in-dual out which is basically an internal x-pipe, straight through/flow through. There's also regular old straight through Magnaflows. I've heard it's a good idea to go with 2.5" piping after the mufflers to keep backpressure near stock level, but if I used a 3" in 3" out dual in-dual out would the internal x-pipe maintain enough backpressure? Anyone have similar setups to these that can offer their 2 cents?

[southcarolina12]

well you need some sort of cross over so i would do it with the muffler instead of having a x/h pipe and having 2 mufflers when you can have the 2 mufflers and x pipe in one.

[Rajin Cajun]

i have 3in all the way gives you plenty back pressure. Are you stuck on magnaflow? It personal choice but sound to loud and no throat. I chose 2 single in/ out 40's.

[Carson92]

i have 3in all the way gives you plenty back pressure. Are you stuck on magnaflow? It personal choice but sound to loud and no throat. I chose 2 single in/ out 40's.

I'm set on not having Flowmaster, that is for sure. I feel your backpressure may come from all the little walls inside the muffler, and I definitely don't want that. I want straight flow through, and Magnaflow provides it.

[grayblazer]

I have dual 3" Dynomax Ultraflos on mine. Just cut out the stock dual in-dual out muffler and slapped in the new mufflers. On the outlet side I just fabbed up some extensions that connect to the stock tailpipes, which are dual 3" that Y into a single 3.5". I did not notice any difference in power including when pulling my 9,000 lb. trailer.

[Ironroad9c1]

YOU DON"T WANT BACKPRESSURE!!! why does everyone keep saying that. you want as little backpressure as possible.
Pardon the Import site. but they pretty much lay it out perfect. ..read up.
http://www.nsxprime.com/FAQ/Miscellaneous/exhausttheory.htm

[grayblazer]

YOU DON"T WANT BACKPRESSURE!!! why does everyone keep saying that. you want as little backpressure as possible.
Pardon the Import site. but they pretty much lay it out perfect. ..read up.
http://www.nsxprime.com/FAQ/Miscellaneous/exhausttheory.htm

I agree with you.......but gave up trying to argue my point a long time ago.

[TheBigBlackHD]

Fvck Magnaflow! Go with a Borla XR-1 or Spintech or Corsa (if you can find just the muffler). Magnaflows are nicer than Flowmaster, but there are much better sounding mufflers for the 6.0! Get an x or h pipe (your choice on which), it will help balance the tones and cut down on mid-rpm bubble. Dual or single muffler is up to you, both will sound good. I wouldn't run tips, I'd just run turn downs right off the muffler.

:read:
http://www.fullsizechevy.com/forum/general-discussion/performance/exhaust/464348-official-borla-xr-1-thread.html

[rebelbowtie]

doing a proper h-pipe or x-pipe on the 2500HD you are going to have to rework a lot of your exhaust. its not as simple and slap it in and go, the placement of the cross over pipe is crucial to performance. in my honest opinion though, you need to ditch the entire idea of dual exhaust all together and get a y pipe made after the aft most cat. runa single 3" exhaust with muffler/exit of your choice.

the exhaust system the 6.0 has in the HD application is the exact same exhaust that the 8.1 uses. point of the matter is its over kill.

[Quiksilver]

My Dad has a dual 3" in/out Magnaflow (with dual 3" out the back) in his '01 2500hd 6.0. It sounds great (not overly loud), although there is significant resonance at certian RPMs.

There was no real loss/gain on the "seat of the pants" dyno. As stated above the stock exhaust has very little restriction anyway.

Phil