Dynamat

[Steam Driver]

Is putting this on the floor under the carpet worth the time, effort, and cost? I.e, is the noise reduction worth the effort or has it just added weight for no good reason?

[kavadarci]

My answer is absolutely yes, I’ve done it on few cars and love it.
One thing to remember is that dynamat purpose is to reduce rattles and shakes and slightly reduce noise.
Good set of Mats or undercarpet foam insulation is to reduce (absorb) sounds like road noise.

All of this adds weight which is a problem if tracking.
Not an issue for me.
Here is mine, I used b-quiet.

[donagain1]

How much weight is added by that stuff? I mean if it's 3 pounds or something, that's what the driver would add after one good Italian dinner with a slice or two of N.Y. Cheesecake for dessert.

[kavadarci]

Yeah it is not much but some guys freak out on any weight.

[Duc Hunter]

Having pulled this out of my rat rod I will tell you the down side. It is a ***** to take out. It also hides all manner of rust. On my car their obviously was water getting under in from the rear windows in places into the rear seat pans, and into the drivers floor pan. Only way I would have know that without pulling the Dynamat out would be when my foot went through the floor. Luckily I pulled the Dynamat up and saw the surface rust, and water. Keep in mind too my car had not been in rain in 6 months, and there still was some wetness under the Dynamat. So I would say don't do it.

Also Dynamat does not need to cover and entire area at all. It prevents metal from resonating when it vibrates. So, for example, you could get 90% of the benefit on a roof panel by putting strips along the roof to cover about 30% of the total area. Many people think Dynamat need full coverage, but you need foam to sound deaden over top of metal that has strips of dynamite. There are a few threads around on sound proofing...that talk about this. I am not expert, just remember that Dynamat material is 1 part of a multi-step process.

[Steam Driver]

Weight not really an issue for me, I just mentioned it as a factor. Actually the noise isn’t either for that matter. But Duc Hunter’s reasons for taking it out are enough to convince me it’s not a good idea for the foot wells and floorpans.

[Flojo]

no dynamat can deaden a loud pipe

no kidding, I "only" have an SC with SSI, but reving that baby brings joy to the ears which no dynamat can reduce to a Merc/Rolls standard.

[fred cook]

When I replaced the interior of my SC, I used the Dynamat from the rear window to the front firewall. I like the way it cuts noise and especially resonance. Unlike Duc Hunter, I have never seen any evidence of water leakage and have no rust anywhere in the car. Of course, my car was bought new in Atlanta and has always lived in Georgia so it hasn't been exposed to the ravages of road salt or sea spray! After putting the Dynamat down, I covered it with a layer of fiber matting and then lightweight carpets. Getting the Dynamat to fit smoothly does take some work. Using a couple different sizes of rollers and cutting odd shapes to fit curves, etc will make for a nice job. I would guess that the Dynamat added maybe 10 lbs to my car. Good luck!

[trond]

I pulled some dynamat (or similar) from a friends SC and was surprised at how wet it was below.
Car appeared to be dry inside. Not for old cars in a wet climate.

[1979-930]

I added it to a car years ago when the stuff came out. I didn't notice any real difference. There are a lot of sound proofing websites now with information about sound deadening a car.
The Dynamat products only cover the resonation part. They are really only needed in small patches in the middle of large panels.
There are mass loaded vinyl mats that work better for stopping the sound waves.

But these products do get heavy when used in the proper layers and IMO are one of the main reasons high end "performance cars" like Maserati weigh about 2 tons.

[macssc911]

I just did my SC when I did RS carpet didnt do the entire space just areas of concern, Porsche does a pretty good job from factory. I used NVX sound deading which you can google. If you want some I bought way to much, I live in Charlotte NC, you are welcome to it if you will pay for shipping to Tn.
Thanks

[Evans, Marv]

I just bought 19 linear ft. of the 4 ft. wide mass loaded vinyl (MLV) backed with closed cell foam (CCF) and a roll of their tape to put in my car. I think it's enough to cover the package tray, floors, & wheel wells. Got it from Super Soundproofing in Vista (If I remember right), CA. Cost including shipping was $400. I'll put some pieces of something like Dynamat in the middle of big panels for resonance. The weight for the roll is 80 lb. I'm not concerned about the extra weight, since the care is used for pleasure driving only. When I asked them about securing the MLV/CCF to the floor & panels, he said just piece it together, tape the seams, & maybe use some tape to hold it up on vertical panels, & let the cover panels, carpet, & trim hold it in place. I'm interested to see how it affects the sound.

[H-viken]

First off, my knowledge is based on what I have been able to learn from reading up on sound deadening. That said, with that caveat out of the way, from what I gather the mass loaded vinyl (MLV) does not need to cover entire panels, or be "sealed". Only smaller pieces or strips are needed since the material is only supposed to reduce vibration. It is the barrier (foam etc) that needs have full coverage to maximize efficiency.

This should mean that you can minimize the additional weight by being smart about where you place the heavier MLV.

[Laneco]

Though woefully unoriginal...a spray-on bedliner material provides really good resonance dampening, is fairly light and moisture is not an issue. Ever. Steve did the tub of his cabriolet with it. That car (convertible) is quieter with a dansk muffler than my coupe with a stock muffler. Quieter for road noise and quieter inside the cabin from engine noise.

You can tint it to match the body color.

angela

[kavadarci]

I did the back of the engine with boom mat spray on, Ive sure it before and on top of the sound absobtion it covers nasty paint nicely.