M813 straight piped

[BigDawg41]

The muffler on my M813 rotted out too badly to be repaired and a new one is kind of pricey. So I decided to eliminate the muffler and straight pipe it. I searched and couldn't find any pictures of how other people have done theirs. If I liked how it sounded and it is going to be permanent,I didn't want to use flex pipe. I searched and found 2 reasonably priced 4 bolt Cummins flanges and 2 flared downspout connectors. I then used 2 90 degree elbows and one flared adapter to connect them in the middle. One elbow has to be a shorter radius than the other for it to line up to the stack flange. I also used 4 band style exhaust clamps to tighten everything and for a cleaner look. It took several hours of fitting,cutting and adjusting to achieve the proper clearances and to get the stack to line up straight. I also ditched the 2 metal springs where the stack mounts to the vertical bracket. I used 2 heavy rubber isolators to hold it better to keep it from moving alot and vibrating bad and making that high pitched metallic squeak from the brackets rubbing.No matter how much I tried in the past to adjust that long bolt with the springs it would always shift and squeak BAD at idle. It still allows for some movement but the squeak is gone. I took it for a 10 mile ride and everything stayed where it should and it sounded awesome from inside the cab. Now I will have to paint it with some high temp paint so it looks better through the wheel opening. I have about $100.00 into it since I got the clamps and one elbow for free from my work.

https://www.youtube.com/watch?v=lXa43JctEAw

 

[wreckerman893]

You'll get tired of that racket pretty quick. Ask me how I know.

 

[swbradley1]

You'll get tired of that racket pretty quick. Ask me how I know.

I'm guessing from listening to Ron's M819 at the Georgia Rally.

 

[73m819]

I'm guessing from listening to Ron's M819 at the Georgia Rally.

Ear plugs ARE your friend, but I LOVE my straight piped 819

 

[BigDawg41]

You'll get tired of that racket pretty quick. Ask me how I know.

Update: What? Did you say something? Ok,OK. You were right. It was cool for awhile but I just couldn't stands it no more-especially the passengers. Had to throw a muffler back on it. Now I can hear the sweet rattle of that Cummins again. What was that again?

 

[simp5782]

Update: What? Did you say something? Ok,OK. You were right. It was cool for awhile but I just couldn't stands it no more-especially the passengers. Had to throw a muffler back on it. Now I can hear the sweet rattle of that Cummins again. What was that again?

The noise actually comes thru your body and into your ear drums even when wearing headphones

Sent from my SM-G860P using Tapatalk

 

[TechnoWeenie]

The noise actually comes thru your body and into your ear drums even when wearing headphones

Sent from my SM-G860P using Tapatalk

I drove my M934 from Bragg to Lewis (NC to WA).

Even with earplugs, every time I stopped for a break, it'd take a good 10-20 mins to stop 'hearing' the engine...

I'm gonna check clearances for mounting the muffler under the cab, and dump 90* to the ground, just past the air line bleeders...

 

[red]

Quieter is the way to go with these trucks if you drive them on longer trips