Sound deadening the Challenger - Let the project begin

[jb1911]

Originally Posted by gnach

Thanks jb1911, the photo helps. That whole under-space is like a drum, with the tubs being like trash cans. I have some adhesive dampening mat leftover from another project and will put some squares one the sides of the front tubs.

Since I took this picture we've used Dynamat extensively on our RV, including the ceiling of the storage compartments. I took the wheel wells off and put a double layer on top then put them back in. Also put a double layer under the dog house (which had NO insulation of any kind). It's so quiet now that we can actually hear the radio while accelerating or driving at highway speeds on concrete roads. Well worth all the money and work.

[carlgorski]

Originally Posted by dstankov

Timon,

Thanks for the correction. I am happy with the results.

I put all that in my Quantum Class C. Doghouse, floors. footwells, hood. What a difference. We can talk now. Next is the doors when I change out the crap speakers it came with. I also sprayed undercoating in front wheel wells.

[JKTANK]

Thanks for the inspiration, I took my engine cover off and started there.

More importantly, I'm hoping to track down the source of my "Thor whistle". I found a spot in the dash where a big clump of wires come through the firewall and filled that with foam..... and changing the grill out by this weekend.

I'll undoubtedly will fill some of the pass-through storage with insulation, and crawling underneath I spoted quite a few spots that could use some rust proofing......and some soundproofing.

[Tupelo Kid]

Following this post caused me to do what I had already decided. Cover the inside of the doghouse with sound damping foam to lessen the engine noise. The product I used is the same material we used on corp aircraft. If it worked on that it had to help my noise level. I used a qty of 2, 18” X 48” sheets.

3M 4014 SOUND AND VIBRATION DAMPING PANELS

Aircraft Spruce (Click image for a larger view)


Make Selection(s) Below To Order


From $33.80 to $87.75


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It took me a couple days to complete the doghouse and the area forward of the doghouse all around.
It took me a week to get a chance for a test drive. Today I did that. I must say, I am very pleased with the results. My wife and I took about a 40 mile drive and both agree it is a big difference in noise reduction.
I also plan to cover the bottom of the cockpit floor area under our feet but have decided to use the black Dynamat / Fatmat material for this due to it being a little less cost and it seems it may work well for that.
It will take more time for me to complete the areas I want to cover but will give another update once it’s complete.

[Wrpt58]

I had the opportunity to take the doghouse off my 29M today. I had read a couple or so threads where there was little to no insulation there, so I wanted to look.
I found that it was completely insulated with a foil back foam and that everything was holding on well. I must have got a unit that was done in the middle of the week!!!!

While I have had a few things that were manufacturing deficiencies, I have found that my unit was put together pretty well. However, I'm still getting deep into it.

[SuperD]

Originally Posted by Wrpt58

I had the opportunity to take the doghouse off my 29M today. I had read a couple or so threads where there was little to no insulation there, so I wanted to look.
I found that it was completely insulated with a foil back foam and that everything was holding on well. I must have got a unit that was done in the middle of the week!!!!

While I have had a few things that were manufacturing deficiencies, I have found that my unit was put together pretty well. However, I'm still getting deep into it.

The problem is the insulation Thor uses is almost worthless. I had the same foam under my doghouse but added two layers of Dynamat on top of it, huge difference.






First photo shows factory insulation, second photo is after adding the first layer of DynaMat, and the third photo is the completed doghouse after adding the second layer of DynaMat.

[Wrpt58]

Hmm. Thanx for the clarification. I'll give it more thought and planning. I have a project at home that I plan on using Raammat or Lizard Skin on, so will consider adding more to the budget for the motor home.
Also like the plan to do a little more deadening immediately under the cab area. Just not jumping fences to get into those areas. Might be a good application for Lizard Skin.

[Tupelo Kid]

Originally Posted by Wrpt58

I had the opportunity to take the doghouse off my 29M today. I had read a couple or so threads where there was little to no insulation there, so I wanted to look.
I found that it was completely insulated with a foil back foam and that everything was holding on well. I must have got a unit that was done in the middle of the week!!!!

While I have had a few things that were manufacturing deficiencies, I have found that my unit was put together pretty well. However, I'm still getting deep into it.

Yes, my unit also had the "Heat Shield" installed in the dog house. It is not much help for the engine noise we all hear. You will need to install a sound dampening material of some type to get the magic sound reduction desired. Then reinstall your heat shield over the top.
I found the full (almost full) heat shield material when I pulled the dog house. It had a sort of sticky back to it but was rather easy to remove. I removed it, installed the sound damp material covering the full unit and reinstalled the heat shield foam material then edge covered all around with alum foil tape. Hope this helps. PS: The photos show the orig heat shield with foam backing, then the new sound damp material added, then both materials added and final completed with foil tape around the edges. SORRY for taking so much of your time. :-)

[Islandsmith]

For those of you who remove the factory heat shield and re-install it over the Dynamat (or whatever sound deadener you use), what adhesive spray do you apply that will withstand the heat from the engine?

[SuperD]

Originally Posted by Islandsmith

For those of you who remove the factory heat shield and re-install it over the Dynamat (or whatever sound deadener you use), what adhesive spray do you apply that will withstand the heat from the engine?

My factory insulation was on pretty good. I installed the DynaMat on top of the factory stuff and didn’t remove it. If your factory insulation isn’t glued down well I would use 3M spray adhesive, good stuff!

[MTHook]

Did you install the Dynamat under the carpet or on the ceiling in the wheel well? I'm replacing the carpet so inside would be the easiest.

[SuperD]

Originally Posted by MTHook

Did you install the Dynamat under the carpet or on the ceiling in the wheel well? I'm replacing the carpet so inside would be the easiest.

I only did the doghouse, several others have done under the floors of the driver and passenger sides to reduce heat under their feet.