Make it quiet. Lower decibel level M809

It's never going to be quiet but it needs to be quieter.
I have added a turbo and Jakes to my M818. The muffler was removed to make room for the turbo. The exhaust is straight through. I've had it this way almost 2 years.
I got a decibel meter to see how load it really is. I played with it today.
Db meter sitting in the rifle holder on the dash, Windows up
Idle 85-90db
Cruise @40mph 93db
Jake brake 104db

It was raining today, I'll get pics or maybe video hopefully this weekend. I'm going to run it again and get a definitive baseline before I start sound proofing.
My plan is to rubberize undercoat under the hood and cab. Dynamat or equivalent the firewall interior and inside the doors. And cut a heavy rubber mat for the floor. I also am considering a muffler. I am leaning towards the stack insert as there really isnt space anywhere.

I am open to suggestions. I already know it's too loud and the dangers of hearing loss.

That's actually quieter than what I measured in the cab of my old m35a2, it was 99 Db in the cab at 2100rpm (50mph ish).

Lizard skin makes a good sound/thermal insulating paint as well but I don't think it holds up as well as bed liner.

Will you coat both the inside/outside of the cab?

Howdy neighbor (relatively speaking) ! Any acoustic mass you can add ( mat, carpet, spray on stuff underneath ) will help. Do you have a hard or soft top? Don't forget to add stuff there too. I am also new to this game and the first thing I'm getting is a set of active noise cancelling blue tooth headphones. I want the world to enjoy the sweet songs of a Hummin' Cummins but also wanna save what hearing I have left. Can't wait to hear the engine brake.

Drop the exhaust out to the frame rail and run it back the back and dump it behind the passengers step. You can get a quiettone muffler as well. I cant hear my truck with my sony headphones on. I take them off sometimes to make sure its still running

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Look into Aero turbine mufflers. I put one on my deuce and like it. They are a straight through design and made of stainless.

I have a soft top. It's insulated but it needs replaced. The fabric of it has gotten thin and is getting harder to repair.
There isn't much room for the exhaust to go under the truck but I'm not counting that out yet.
I ordered some 80 mil noico, like dynamat. After I set some baseline numbers I'm going to paint and undercoat the inside of the hood. That's a lot of real estate.
Headphones would work fine for me but I'd like to be able to talk to passengers. I'd also like to take my 2 sons for rides longer than 10 minutes. I guess that's my real reason for doing this.

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I found that EAR PLUGS work great while driving the straight piped 819.

What?

Std big rig muffler, CH Mack, took 3 out of the dumpster at work and made 1 good one. 4" dia pipe. NAPA elbows, 2 pc rings. Same as deuce but bigger. Very happy with this mod.

73m819 said:

I found that EAR PLUGS work great while driving the straight piped 819.

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Your ear plugs don't do a thing for all the poor souls around you though.

swbradley1 said:

Your ear plugs don't do a thing for all the poor souls around you though.

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True

Army noise comparison
https://www.google.com/url?sa=t&sou...sEh0E8PmAMyVYnACg&sig2=P4lnHyrmk6O4k9Qc4q8tAw

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I didn't think I could fit a full muffler in the mirror bracket. That sure opens up some more options.
That's a nice install.

swbradley1 said:

Your ear plugs don't do a thing for all the poor souls around you though.

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I've heard your suckers are pretty good though. (Ron said so anyway...)

swbradley1 said:

Your ear plugs don't do a thing for all the poor souls around you though.

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I have nothing to contribute to this thread but I certainly appreciate this comment. A few years ago while I was in the tent city at the GA Rally, my family was awoken by an M819 with no muffler trying to back over a hill with an inoperative sprag. My wife was so mad with the amount of noise that she rounded up the boys out of the tent, loaded up and hauled tail. I think the boys were around 4 and 6 at the time. I had alot of explaining to do as to why the dirt bikes can't fire up at first light but the big trucks can do as they please. My trucks have mufflers.

The noise maker! 86.6db at idle, in cab, windows up
Trying to make a mount for my dash cam now. Video to come

Only 103 db on todays outing.
My dash cam doesn't have a very good mic evidently.
First attempt at video

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//cloud.tapatalk.com/s/5906313458c37/MOVI0008_1493577620958_1493577817604_1493577890285.mp4
A short clip from the video I took. Next time I think I'll just use my phone, it has a better mic.

The tapptalk link is requiring a download before play.. careful, the Mods will get upset if linking continues... they tend to like the embedded video....
not trying to be the fun police, just seen a couple other guys get scolded for the tapatalk stuff recently in other threads..

really interested in the noise level reduction. I need it bad....

wcuhillbilly said:

The tapptalk link is requiring a download before play.. careful, the Mods will get upset if linking continues... they tend to like the embedded video....
not trying to be the fun police, just seen a couple other guys get scolded for the tapatalk stuff recently in other threads..

really interested in the noise level reduction. I need it bad....

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Ok thanks. The video is not that great anyway! That was my first time playing with my dash cam and trying to post video. I'll figure out how to embed the next video.
I'm hoping to get my truck under 90 db