Noise Reduction

[browerw]

I have a 98 2500 4x4 5 speed with the one of last of the 12V's.

This has been a great truck, but on long runs(800+ miles) the noise in the cab is hard to handle. I have been in 97's that are much less noisy. Is this an inherent problem with my truck and has any one had sucess at cutting the noise levels in the cab.

Anyhelp would be appreciated

 

[Doc Tinker]

Welcome to the TDR forums



I have dabbled in noise reduction and am always interested in new products and ideas. Several of the guys have practiced extensively with noise control and will soon fill this thread with advice. The latest product seems to be a lead lined foam product that LSFarm has been putting in his truck. I am patiently waiting for him to complete his tests of the product, so I can sit in his truck and appreciate all his hard work and then follow his lead.



Doc

 

[BCFAST]

I talked with LSFarm today in Florida today about the "super-foam" and we discussed at length the result that he and I have. Mine is mid-project, his is more about done... just wait til you hear what he has to say! For those who are unfamiliar, this is a foil-backed foam with lead sheet layers in it, that I found at a marine sound-proofing specialty shop in Ft. Lauderdale. They have been around since the early 70's and all they do is sound-proof engine rooms and generators... they KNOW their stuff!

 

[RJ2]

12,000 members you would think that someone would have come up with something by now.

 

[Lsfarm]

Operation Quiet Cummins

My 'Operation Quiet Cummins' has been a long project, but I think I might be nearing the end.



The 'super foam' that Brian [bcfast] found in Ft Lauderdale is a very effective product. The company is called GSI for Great Southern Insulation Company. Their site is www.soundstop.com



I negotiated a 15% discount for TDR members, just mention the club name to Ron, one of the owners. He is very helpful, and will ship from his shop with phone orders.



The soundstop foam is heavy, about one pound per square foot. The 'lead' [it's not actually lead] layer in the foam really deadens the Cummins clatter.



Browerw, if you will email me, I will send you some photos and text from my project. -- email address removed --





Greg L

 

[Chipstien]

Lsfarm, where did you end up applying the foam and how thick is it. A pound per foot,:--) if you add enough you will need the comp to keep it moving.

 

[Lsfarm]

Email me

Chipstein : email me, I have a group of photos and text I can send you. I don't want to rewrite the whole thing here tonight.



Short answer:

firewall

under carpeting

on back wall of cab

valvecover

oilpan

ahead of windshield, under plastic grill



-- email address removed --

Greg L

 

[Devildog]

As a matter of fact.....

I just finished my sound deadening project this weekend, did 2 layers on the floor, 3 layers on the back wall about a month ago, and this weekend did 2 layers on all the doors. what a big difference http://www.b-quiet.com I used beaver tail on the back and floor ( which they don't carry anymore), and brown bread on the doors.

 

[Lsfarm]

Update: 'Operation Quiet Cummins'

Hi Guys, I added a few new pieces of foam to my truck this morning, and have taken a few new photos. If you want to see the new pics just email me at -- email address removed -- I will get them shrunk to email size and get them out tonight.



I have found that the intake manifold and air intake horn are huge radiators of sound. Now that I think about this, it makes sense, the manifold is bolted directly to the head, and therefore would conduct the sounds from the head, injectors and combustion chamber.



I took a 'sound pressure' Db reading before and after adding a simple 'drape of foam' over the back half of the intake manifold, and a wrap around the intake horn.



Before, measured at about 18", meter aimed at the base of the intake horn: 96 Db, at idle. After the quick application of the foam, 92 Db. It is noticably quieter.



For you noise junkies: this truck still sounds like a Cummins, it just doesn't drown out conversation on the sidewalk when you stop at a stoplight.



Db levels at the left wheelwell, measured at 6' distance dropped from 86 to 84 Db. Still a long way from a gasser. They read about 72 Db.



Greg L

 

[Sageair]

I have been working on quieting down my 2001 and have had good success using a foam sound deading material from super soundproofing. A significant improvement came of course from an engine blanket but maybe even more effective was addressing the bare metal found on the firewall up under the dashboard and on the engine side of the firewall.

 

[RedRamer]

Sageair

How hard is it to get in under the dash? Dash removal?

thanks

 

[TPCDrafting]

Turn up the radio=less engine noise.

 

[Sageair]

Goober

If you kneel down outside the drivers dooe and look up under the dash just above the carpet line you will see the bare metal of the firewall. No assembly required hehe.

 

[dseabaugh]

When Uncle Frank put the 1160 cat motor in his International Pickup in the 70's he lined the firewall with sheet lead. Our Rome tractor came from the factory with lead lined foam to deaden the sound of it's 525 Hp 3408 Cat v-8. Oo. Oo. Tractor came from the factory no muffler, just an elbow off the turbo If you don't believe lead deadens sound hit a chunk with a hammer. surprisingly quiet.

 

[RedRamer]

As a matter of fact, that's what I'll be using.

I got 2 rolls 4'x 8' sheet lead @ 2lb / sq. ft.

Basically what you want to do is add mass to the sheet metal. cheap too!

 

[dseabaugh]

goober, where did you get your sheet lead? I have been looking for some myself for my truck and our diesel lawn mower, tractors.

 

[CCahill]

Greg seems to be leading the way in this field... plus very free with info. . 1 thing you need to check out are the seals @ the doors. . these seem prone to slippage. . I also took off the cowl cover and sprayed expandable foam into the opening between the holes. . just make sure you don't foam up the fresh air opening.



Right now I'm also working on a door seal near the mirror area, this area seem to transmit noise also, and just has a very this w/s to keep out moisture/noise... don't bother with hood insulation unless you have an 02 truck. . it doesn't seem to help at all. .



Again, thanks Greg for all the hard work you've put into this. . PS. . If I ever have to pull my engine out(unlikely), I'm goin'hard at that firewall... they sure chinzed out at the factory. .



Colin

 

[RedRamer]

deseabaugh

Co. out of Montreal, Canada Metal... 1-514-327-2011

cost me $112 + $45 shipping Cdn = about $100US.

It's called 1/32" PB sheet (2#) prod# C3302.

I got it mostly for inside panels floor. Outside and tough areas, I'll prob use something like LSFarm did.

 

[Lsfarm]

Operation Quiet Cummins

Colin: thanks for the kind comment. This project has become an obsession. But at least I can measure some positive results since I purchased the dB meter [good idea Rip!]



I had Steve StLaurent and Rob [RamThisOne] over doing a project in the shop yesterday, and was able to do several side by side comparisons to their trucks. There is no question: I'm making progress.



Goober: thanks for the lead on the lead [pb] sheeting. I called them, but they were closed for the day, I'll call tomorrow. Was that price for a 4'x8' sheet? That's not too bad. I may buy some and use it on the floor of the cab. It may help block the remaining slight drone from the exhaust.



Colin, I'm going to give the door hinge area a good look-see and add a few pieces of foam to seal the open areas. Did you notice any noise reduction when you blocked the passageway under the windshield with spray foam? I have insulated both the trough and the passageway behind, but didn't block it in the center.



One good thing about all this work: we may avoid needing hearing aids in our later years.



Greg L

 

[HEMI®Dart]

ATP is probably the best, but $$$

https://www.turbodieselregister.com/reviews/ATPI.htm



http://www.atpwrap.com/dodge_ram.htm