2nd Gen Non-Engine/Transmission 2nd gen cab noise

[woodtrucker]

Hey Guys, So glad to be posting on this forum once again! I love this place.
When I bought my first cummins a year and a half ago, it had whoppin 5" straight pipes and I couldn't stand it pulling the camper with the fam so I put a magnaflow straight thru, 5" muffler on it and that made the exhaust just right.
I recently tried salvaging what's left of the dash but filling in all cracks to prevent them falling completely out, with ABS cement and putting a cloth cover over it for easy access if needed. I opted against the dash cover. I will do a full dash replacement but that's another story for another time.

So when I put the cloth cover on the dash, strangely enough, the cab noise at my face got louder and more annoying. I guess it directed the noise more toward my face and less up through the dash and over my head??? I could be crazy but it sure has been a lot of loud engine noise.

Anyway, my question is, has anyone put any sound deadening material on the firewall inside cab to just help muffle down some of the noise? If so, what'd you use?
I'm 38 and even at 18, I'm not sure I could stand the noise.
Thanks,

 

[BarryG]

I know the 2nd gen is loud. If you do a search on here you will find many threads about it. There are couple from quite a while back(ten years) about doing it right lead sheeting etc. I used a variety of products. From Bquiet http://www.b-quiet.com/collections/all and some dynomat extreme that I got at a great price. The bquiet stuff I used had very similar specs to the dynomat extreme but at half the cost.
A great website on how to do it or the reasons/science behind doing it properly is http://www.sounddeadenershowdown.com/

I used the method of dynomat etc with multiple layers which certainly helped but not as much as it could have had I known about the proper science behind doing it. Which is given in the link just read through all the links in the page and you will learn more than you want to know about the subject.

The back wall of the cab has no insulation at all. The floor has minimal as does the firewall. The doors have none either. The cowl area under the hood is huge and is nothing short of a cave. Another area with nothing which will help with wind noise is the front fender to cab area. I stuffed a couple of cut up pieces of the Styrofoam pool noodles in there and it did help some.

For my install I did a layer on the inside of the outer door skin, the inside of the inner door skin and the outside of the inner door skin, 3 layers across the back wall and 2 layers on the floor and firewall as far up it as I could reach. I also put what I could in the cowl area. With a portion of leftover material more less over the exhaust pipe on the floor through the cab for essentially a third layer in that area. While the difference was noticeable I know if I had known then what I know now it could have been much better. I did not do the roof though it has nothing except the headliner. I did not want to pull it down at the time but when or if I ever do I will tackle it as well. You will have to remove the seating to do a decent job and is not at hard to do. Just get your materials and plan on a long day or so,

 

[woodtrucker]

BarryG,
Sorry it too me so long to respond. Been on another rabbit trail with tuners/injectors and the likes. I will check out your links and definitely keep your info in mind. I'd love to get this done in spring before the five of us shove off to the ocean for our camping trip. Thanks A bunch! Scott