Engine/Transmission (1998.5 - 2002) Straight Exhuast

[PMurphy56]

Since we live in a rural area, my son talked me into cutting the muffler out

and welding a straight piece of pipe for better exhuast flow. A friend has said it will through off the computer which is programmed for muffler back pressure. Sounds kinda lame to me but I thought I would through this out to see response.





02 3500 sport 6 spd. 3. 55 stock.

 

[dslmacdown]

Don't believe it! Cut that muffler off and you will love the way it sounds. I used the kit from Geno's and can't hear a difference inside the cab but outside everybody says it sounds like a big rig. In stock form it won't make much difference but will help with power mods.

 

[DManey]

The straight pipe got my turbo spooling up quicker and I actually saw quite a significant increase in fuel economy, 2-3 mpg.

Derek

 

[Joe Mc]

Removing the muffler wont hurt a thing. Diesel's don't "need" back pressure like gassers. And, as far as an increase in fuel economy . . . I don't know . However, I do know that removal of the turbo silencer ring is directly related to increased pressure on the right foot due to the noise entering the right ear which sends the "increase pressure" signal to the right foot which . . . it's a vicious cycle :-laf - ultimately ending up with reduced fuel economy and increased eeehaaaw factor :-laf :-laf

 

[johncameron]

Make sure you leave the resonator in place. Without the resonator it is a drone pig but with it the in-cab noise is almost the same as stock. I took both off and 3 weeks later I was back at the shop putting the resonator back on as I couldn't stand the drone. I was all smiles for over a year with my straightpiped 3 inch system. Now I have a 4 inch straightpipe with a tiny resonator and it really sounds like a big rig now!!



John

 

[JHerrlich]

I personally found that the straight piped 3" was a little obnoxious. I actually got pulled over for being too loud. It's not too bad when you take it easy, but when you get on it, people cover their ears.



Since going to the 5", sounds much better...



And to the original question, turbo itself creates back pressure. Your computer won't know and isn't able to tell the difference anyway.

 

[RJPotts]

I agree. Backpressure is the enemy in a turbocharged diesel. The less you have (within reason) the better. And there is nothing the computer can read that will make the truck run poorly or throw any codes with less backpressure. You could take the exhaust completely off (not recommended) and the computer could care less. Until it melted of course. And as JHerrlich said, the turbo alone creates any "necessary" backpressure.

I say forget about the muffler, remove the whole exhaust system and replace it with a 4" system and get some stacks. No muffler, no resonator, give it h*ll.

-R. J.

 

[kelly4463]

Straight pipe to 6" stack's sound's the best,let the coal roll :-laf :-laf :-laf

 

[WyattEarp]

well i got my 4" pipe on tuesday installed it today... not sure how im going to work the hanging of the pipe, sort of riged up right now but is together, I ran 4" pipe a 5 1/2 foot peice from the resonator back, connected with a 8"inch 4OD-4OD connector, sounds just like the MEK kit i got from Genos back 3yrs ago and actually was cheaper for me...

Is there a place to get a turndown with a 5"OD to connect to the end of the pipe, Nope i didn't get it bent, no place around here deals or bends pipe thats over 3"... . Any suggestions on that. . i need a turndown or i may end up melting the back of my bumper where the plastic part is. . :-laf

 

[kelly4463]

I got all my pipes and clamps elbows from a big truck parts shop good luck

 

[bmoeller]

The turbo creates back-pressure. After the turbo, you want to keep back pressure to a minimum.

 

[WyattEarp]

I meant to say that my connector was 4" ID on both ends got that mixed up. . I have checked with one place in MI. . but im unsure as to how their site reads, may have to do some more checking around to find one. . But i would need a 4" ID turndown i believe to go over my newly installed 4" pipe, correct?

 

[Kissfan113]

i am really happy with 3 inch to 4 inch to 5 inch y pipe and stacks, can't wait to get 4 inch all the way to the y pipe though. I know it completely cut out all the drone when i went to stacks, no resonator and no muffler, staight piped, stacked and lovin it!!!

 

[Katmandu]

Don't believe it! Cut that muffler off and you will love the way it sounds.

I totally agree!! Sounds like a Freightliner!

 

[Katmandu]

I do know that removal of the turbo silencer ring is directly related to increased pressure on the right foot due to the noise entering the right ear which sends the "increase pressure" signal to the right foot which . . . it's a vicious cycle :-laf - ultimately ending up with reduced fuel economy and increased eeehaaaw factor :-laf :-laf

I haven't yet heard the whistling effect of removing the silencer.



Does it whistle out the exhaust like a Military (2 1/4 ton) Duece and a 1/4 ??



If so, I WANT that type of whistle !!!

 

[Katmandu]

I got all my pipes and clamps elbows from a big truck parts shop good luck

How much was it ??

 

[wtfd6]

i dont have stacks. but my 4 inch tail pipes with no muffler sound great. i love hearing the turbo sound at idle.


mark

 

[Cummins724]

Is there a place to get a turndown with a 5"OD to connect to the end of the pipe,

]

I have a 4 inch exhaust, called summit & ordered a bullydog turndown for $60. 00. It looks awesome & stainless steel too, can't go wrong.

 

[Joe Mc]

I haven't yet heard the whistling effect of removing the silencer.



Does it whistle out the exhaust like a Military (2 1/4 ton) Duece and a 1/4 ??



If so, I WANT that type of whistle !!!

Kat I hear it as I still have the stock air box with the tube to the fender removed - You only hear it at a cruise between 4 - 8 # when you romp it you only hear it for a brief moment as it goes through the 4 - 8 # range.

 

[C.Solomon]

I love the sound of my straight pipe, it has a nice riiiipppp in 2nd and 3rd.

My buddy has straight 5" and that thing is so sweet sounding when you hammer it down in 3rd.