Removing muffler from exhaust system?

[mcdougald7824]

So I have heard mixed discussion from people in my area and figured that I would post it here to get more feedback…

Like everyone else I’m thinking of ways that I can improve my fuel economy. I have already improved the airflow into the engine so now I’m thinking about the exhaust. A 4” exhaust is not in the budget so I was thinking about removing the muffler from the exhaust system to improve the air flow. But how loud will the sound be coming out the tail pipe? I have heard fords and lil old chevys without their mufflers but still have yet to hear a Cummins running naked.

So my question is: To remove or not to remove the muffler from the exhaust system on my d250…

[92 D/UNIT]

In my opinion not a whole lot sounds better than a straight piped 12 valve.. it wont be extrmely loud and will help it breath a little better.

[ellis93]

Do it! You'll love the sound. I didn't see any gain In milage from it tho.

[JBradley500]

i went from a 3" system with a dynomax free flowing muffler (off of my cousins 358 modified) to a 4" straight pipe when i upgraded turbos. i hated the straight pipe noise. i just recently installed a resonator and i love it. straight piped cummins sound great when they drive by you but they drive me nuts when i have to ride in them.

[rebel horseman]

I straight piped mine a while back and do not regret it one bit. The sound is not obnoxious unless you open all the windows or drive next to a wall that will reflect the sound. It may have helped fuel mileage but it did help performence a little in that the turbo can spool just a little bit easier. I say do it; if you don't like the sound take it to a muffler shop and tell them to weld in a glasspack.

[peobryant]

Heres a video of a truck with a 4" system...

http://www.youtube.com/watch?v=oeEVqWyl9B0

I don't regret straight piping my truck at all. The first day it seemed really loud to me (I drove around with the sliding rear window open all day ) but now, especially with the windows up, you won't even notice it. A 3" system may bea little louder than a 4", but it won't matter a whole lot.

[Renigade]

I have mine straight 3 inch all the way back and just came off a 3500 mile trip. The only complaint I heard was from my wife about she can't hear her cell phone. I explained to her about ear buds. I had a Texas highway patrolman in south Texas that complemented me on the sound of the old cummins

[93oilburner]

when I removed the factory muffler on my w250 i gain 3lbs of boost on the upper end. Now i have the front half 4in and after t-case is 5in up to a single stack. sounds good after turbo spins up but droons at lower revs, might put a 5in resonator in before the stack.

[Mark Nixon]

What's a "muffler"?
Ya' gotta' offset the engine's normal injection noise with an exhaust note, it's only the right thing to do.

Mark.

[1990]

I put a Magnaflow straight through muffler after i tried the straight pipe for a bit.

It's super quiet in the cab and it's not restrictive.

Here's what the muffler sounds like.

[Renigade]

That sounds pretty good. I have a friend that owns a muffler shop and makes his own mufflers and I may just go talk to him just to keep the wife off my back.

[Greenleaf]

I have built a number of exhaust systems for my 90 and 92. Some sound better than others. It really depends upon you.......and where the pipe terminates. In front of the rear tire is a bit extream for sans muffler. Made my head swim. The stacks were too extream as well.

With my 92 stacks made from 4" pipe into 5inch it was so bad I couldn't drive it. However, with a four inch system dumping into a 6X6 steel box "frame" for mounting and supporting the stacks, it was very pleasent.

My 90 now has a tail pipe pointing out the right rear "corner" with a four inch system and no muffler. However, I work with the State Highway Patrol. And one of the guys heard my truck running and came over to look. Under the truck. And said that is a 250.00 fine so I had best get a muffler.

I'm currently building the "Faux Muffler" from 4" pipe and a 7" muffler body. Will look like a muffler to the eye, but won't sound like one.

Yea..I can't wait to have a highway patrol look under that old 90 and see the faux muffler but not hear one.

Oh, my 92 has a resonator, not a muffler. So they think it is.....a muffler. But it ain't