4 inch Exhaust???

11728 Views 19 Replies 8 Participants Last post by Drag Limited, Apr 30, 2018

Burgess159

Discussion Starter · Sep 16, 2017

So, I don't know if all of you are a member as well of the Facebook groups, specifically the 2.8 LWN Duramax Owners. But a new member on there posted a video of his truck, tuned and deleted. Special thing about his is that he went with a 4 inch exhaust. Don't know if was a total straight pipe or had a performance muffler on there or what but I feel it was w/o a muffler.

Wish I could share the video but I don't think there is a way to share just a facebook video, as it will then direct you to the page and if you're not a member, I don't think you will be able to see it. But the truck sounded great. Had a lot better tone than any other truck I've heard so far. Guy said there is no drone while driving at highway speeds either.

He said he went with a Diamond Eye 4 inch down-pipe back exhaust. If you look on Diamond Eye's website, you will find they have no such exhaust for our trucks. I asked him about this, and he said that he customized an exhaust off of a 2nd Gen. Cummins from Diamond Eye to fit his Colorado. Not sure why he chose a 2nd Gen. Cummins though, not sure if they match the length of our trucks frame/ current exhaust system better and have a similar sized down-pipe (Ours is 2.5 inches I believe. 2005 Duramax's have a 3 inch for comparison) opening or what.

This is the 2nd person I have heard who customized a 4 inch exhaust from a bigger truck to fit our trucks. And they both sound great. I think I would consider trying this, as it didn't sound like any extra pipe bending was involved, you just had to do some trimming. Anyone else heard of people doing this and thought about doing it themselves?

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Rockcrawlerdude

· #2 · Sep 16, 2017

I'll try to get someone who has Facebook to pull that up so I can listen to it.

Get one made. Would be awesome.

Any competent diesel shop or exhaust shop can make you an exhaust system. Just tell them what size pipe you want and where you want it to exit and let them do the bending and welding. Good part about that option is if you ever have a hanger or something bust loose it rattle you just take it back to them and have them repair it free. I like this option over mail order bolt on kits that use clamps. You end up with a one-off hand built exhaust, too. Exhaust shops have pipe benders and spreaders etc. The shop I use I just give them creative freedom and they take it from there and they always blow my mind. One of my favorites they did was a hidden side exit on my tundra.

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Burgess159

Discussion Starter · #3 · Sep 16, 2017

Nice. Yea, one of the guys I used to work with, he just opened up a repair/ performance shop. He is good with anything, especially diesels. And a good welder. I might take it to him when I do it. Thanks

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Burgess159

Discussion Starter · #4 · Sep 16, 2017

Oh, and that guys name that has the truck I'm talking about is Jordan Chailland. Search for the video with his name at the top.

Rogerwh0

· #5 · Sep 18, 2017

He has it on Youtube now
It does sound good

Reactions: 3

Burgess159

Discussion Starter · #6 · Sep 18, 2017

That's the one!

RollyPollieBenito

· #7 · Sep 18, 2017

Sounds really cool.

Pergrem

· #8 · Sep 18, 2017

That's probably one of the best sounding setups I've heard for the 2.8.

AndyZ71

· #9 · Sep 18, 2017

I'm impressed.

Pergrem

· #10 · Sep 24, 2017

I would like to hear a video of in cab and a fly by video to hear the engine under load.

Also curious if there is any loss of power. Usually gain little HP while sacrificing little torque with a larger exhaust.

Rockcrawlerdude

· #11 · Sep 24, 2017

Pergrem said:
I would like to hear a video of in cab and a fly by video to hear the engine under load.

Also curious if there is any loss of power. Usually gain little HP while sacrificing little torque with a larger exhaust.

While true in n/a vehicles, that isn't true in a turbo vehicle because there is no back pressure after the turbo. You could run 5" pipe all the way back if you wanted.

Burgess159

Discussion Starter · #12 · Sep 25, 2017

Yea, usually the exhaust manufacturers claim that you will gain among other things, hp, torque, engine or turbo cooling, all because you're getting the air away from the engine faster with a bigger less restrictive exhaust. 5 inch would be awesome. Someone should do it and report back

Also, I thought that guy posted somewhere another video and said there wasn't much in cab drone noise at least. I imagine you hear it when you get on it, but perhaps because it's larger, it lets air escape more easily and thus doesn't make as much noise. I mean, you hear gas trucks with like 1 inch pipes and they kill your ears when they rev up. A diesel with a 5 inch exhaust revs up and it just sounds good. Just what makes sense in my head though, don't know if it's true

Pergrem

· #13 · Oct 12, 2017

Here is his fly by video

I think this is the way to go. Wonder why companies don’t sale a 4 inch

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Burgess159

Discussion Starter · #14 · Oct 12, 2017

Maybe the will. Full size pickups get offered 4 inch and 5 inch exhausts from aftermarket companies to replace their stock 3 inch. Would think companies would do 3 and 4 inch aftermarket exhausts to replace our 2.5 inch stock one.

Rogue_One

· #15 · Oct 13, 2017

Hi everyone,

I am new to Diesel's and would like to do this with my vehicle but was wondering how do you pass emissions tests after doing this?

Rockcrawlerdude

· #16 · Oct 13, 2017

Rogue_One said:
Hi everyone,

I am new to Diesel's and would like to do this with my vehicle but was wondering how do you pass emissions tests after doing this?

You don't

Burgess159

Discussion Starter · #17 · Oct 13, 2017

What RockCrawler said: you can't. Unless you move to a place that doesn't have to pass emissions. In Missouri, if you live in St. Louis or St. Charles county, you have to pass inspection and emissions. Same for Kansas City and maybe Columbia and their counties? Anyways, all other counties, you have to pass a vehicle inspection but no emissions. To pass vehicle inspection, on say your vehicle was equipped with a Catalytic converter and muffler and whatever else, it has to have it to visually have it to pass but the emissions aren't actually tested.

Pergrem

· #18 · Oct 14, 2017

I’m going to try to do this in a couple of months. Right now I’m trying to find a good shop that can work with 3” and 4” stainless steel pipe before I start looking into what I can do with the down pipe

Rockcrawlerdude

· #19 · Oct 14, 2017

Pergrem said:
I’m going to try to do this in a couple of months. Right now I’m trying to find a good shop that can work with 3” and 4” stainless steel pipe before I start looking into what I can do with the down pipe

I did some chatting with people on the other colorado forum. Many many people are deleted over there. Someone recommended keeping the stock downpipe, seems to help with black smoke. The cat is in the stock downpipe. The dpf is the thing that clogs up not the cat. I think if I were to delete I would keepbthe stock downpipe and have a shop make me an exhaust from there back with a muffler. Or I would use the flo pro kit and may or may not use their downpipe

Reactions: 1

Drag Limited

· #20 · Apr 30, 2018

I'm really surprised the aftermarket does not have this size exhaust as a pre-built option. This is the best sounding exhaust i've heard on the twins.

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