If ya got duals exhaust come on in here!!!

3500duramax · December 25, 2003

I have heard several HD's around here that have duals on them and i want to put the same thing on mine. I have the 8.1. The one i heard, he has them comin out the corners and when he gets on it you can literally feel it pounding your chest and it cackles and everything. thats what i want. what would i use. 2 1/4 pipes and dynomax bullets?? i know 2 1/4 makes it really cackle and raspy. so tell me what you have on your trucks and what it sounds like!! RACK UM!

Mike's 2500HD · December 25, 2003

I have a 2001 2500HD with a 6.0 liter. I have duel 40 series flowmasters coming staight out the the back. I think it is all 3 inch tubing with echo tips in the back. It sounds pretty good. Nothing like a big block. It doesn't seem to have the deep throaty sound of a big block. It seems to be more of a hollow throaty sound. I bought the truck used and it the previous owner had changed the exhaust. I am thinking about stepping down to 2 1/2 inch duel magnaflows. I hear they sound great. BTW...the echo tips seem to reverberate the sound into the truck.

2001 HD · December 25, 2003

I think I read somewhere that the 6.0 and 8.1 use the same factory exhaust. DMAX gets a different system. I think other than the muffler, the factory set-up is pretty free flowing. I'm looking at the Flowmaster dual 3" in /single 3-1/2" "50 series Big Block"out listed under RV(I think). But they list the whole system and not just the muffler. I would like a little more rumble without losing much or any low end. And someday.....ASM Longtube Headers!

Hey Mike, does your system have an X pipe?

Philmo · December 25, 2003

i got an '01 reg. cab 2500 HD w/dual flowmasters. i also got the 8.1 and 6 speed.

jelisfc · December 25, 2003

My '99 5.7L had true duals factory to the muffler. I ran 2 1/2" dual straight pipes off the factory 2" duals. Sounded great except it got a little loud towing.

If you like blatty sounding pipes go 2 1/4" but you'll need good mufflers. I strongly recommend at least 2 1/2". Long time ago I had a big block 4x4 with headers and hand made 2 1/2" straight pipes. Loud doesn't do it justice BUT I could get away with it because the larger pipes deepen the tone.

I've run both out the rear and side exit. Rears seem to be quieter in the cab. Side exit are better if you tow so the sound doesn't bounce off the trailer. That was my problem with the '99.

Good luck.

Mike's 2500HD · December 29, 2003

Sorry for not writing in a while...I have been on leave and unable to get near a computer. I just checked...I don't have an X-pipe. I am currently looking at 2 1/2 pipes and magnaflows. I am not quite sure why GM would run such a large pipe with a small block. The large pipe just takes away from the low end torque.

1BADHD · December 29, 2003

The back pressure is a myth on the new LS1 engines........the bigger the pipe the better. These engines want to breath! Anyway, I have a dual in/out and have 3" dual pipe running the the spare tire area and then dumps there. It sounds great. The 3" pipe gives it a nice low rumble. The Magnaflows are a great choice. You dont need and x-pipe, but the do help when going to true duals. Just to balance out the exhaust pulses. Other than that, unless you really built up your engine, you dont need one.

Woody1 · February 17, 2004

I got Borla cat backs. They have a VERY nice rumble and you can hear the engine going down the road. (Nice low rumble. Puts the wife to sleep on long trips!) When you get on it, anyone around can "feel it" in their chest. Every now and then, I will drop my boys off at the bottom of the drive to bring up the trash cans. I'll gun it and they will grin each and every time. If you go down a steep hill and downshift, manually, it sounds awsome. 3" pipes out each back end behind the wheels.

LikeaRock14 · February 17, 2004

Time for me to put my two cents in

If you're going to run true dual, RUN AN X PIPE OR H PIPE!!!!

If you don't you will be dissapointed. the balance pipe makes it sound a hell of a lot better. Without it, it may just make a loud pop pop pop souind, very uneasy sounding. Some people like this though. With it it will also have a better performance gain and a better mileage increase.

With a 6.0 ltr running true duals, mainly if you tow, go with 2 1/4" out. You won't lose a lot of low end and you will still have a higher rpm increase.

Every engine needs backpressure to gain torque! If you run 3" dual all the way, you will notice a significant decrease in low end, and it will make an echoey sound, especially if you run 3.5" to 4" tips along with that. Flowmasters sound great on the 6.0's, mainly the 50 series and 70 series in my opinion (I'm not a fan of two chambers). The new super 40 should sound aweosme with a 6.0 too. Magnaflows sound great on them too. Another possible setup is a Spin Tech system, w/ dual pro street or sportsman street mufflers. They produce they're own unique sound, theyre chabered (sorta), and they have no interior drone!

When I redo the exhaust on my truck this summer, I'm going to run one of these two setups for my 454:

X pipe, h flo 2.5" cats, dual 50 series stainless delta flow flowmasters or spin tech sportmas street mufflers, 2.5" dual side exit w/ 3.5" rolled tips.

dual ho flo cats, 3" dual in flowmaster 50 or 70 series or spin tech sportsman street, 2.5" dual rear side exit w/ 3.5" rolled tips.

when I first had my 70 series installed, I didn't lose any low end. I gained a noticebale increae up top, mainly while towing. The K&N intake helped a lot down low though. A chip will make this combo of exhaust and intake work great.

but for you, w/ a true dual setup on a 6.0, I'd say run an x pipe BEFORE THE CATS, dual super 40 flowmasters or magnaflow 14 or 18" mufflers, 2.5" dual out with 3.5" tips

Hope i helped a little!

Dolan