Sound and Vibration Dampening

[DamnedButDetermined]

I am going to build my S13 from the ground up, and want to get rid of the excess road noise and vibrations.

I know this is against many of yours morals (to add weight to a car), but I want to have a Luxury 240 and a daily driven 240. So I don't want to hear the road noise, the whine of the transmission and the klunking of the differential.

I was thinging of spraying the dynamat sound deadening material over all of the metal in the interior, but then I have seen a few cars with the peel and stick on type dampeners.

What have you guys seen and used to quite road noise?

[nissantuner22]

sound deadening will do wonders, however you will have a lot of inheritent wind noise that will be all but impossible to fix due to the shape of the body, and window design.

[TurDz]

dynamat isn't good enough. You want to go for aluminum foil-lined carpeting material (heat shield) on top of the dynamat type material. Closed/open celled foam also works too. If you want to quiet the undercarriage you also have to spray some insulating material underneath the car...

It's a super task to quiet down a car....

[MakotoS13]

just lay some dynamat dude. this car doesn't have much wind noise due to its sleek physique. new carpet helps a lot too.

[nissantuner22]

i dunno makoto, it might be all the dents in holes in the side of my car, but at 80 mph, i have some serious noise.

[DamnedButDetermined]

dynamat isn't good enough. You want to go for aluminum foil-lined carpeting material (heat shield) on top of the dynamat type material. Closed/open celled foam also works too. If you want to quiet the undercarriage you also have to spray some insulating material underneath the car...

It's a super task to quiet down a car....


Do you have any manufacturer names that I can look into?

[MakotoS13]

i dunno makoto, it might be all the dents in holes in the side of my car, but at 80 mph, i have some serious noise.

the way our doors are designed keeps the sound level kinda high too. 15 year old cars tend to shift a litlte more and the fact that there is no top of the door for the glass to meet makes it hard to keep things quiet.

p.s. they aren't dents they're "speed ruffles"

[sykikchimp]

Brown Bread, and Dynamat are both excellent. There are other forms of dampening materials that work, and are much cheaper though. I got a 1' x 50' roll of some generic aluminum backed stuff a few years ago for dirt cheap but can't remember where I got it.

Check out caraudioforums.com. Lots of good info about this exact topic.

[papershot]

I've been looking around all the sound dampening stuff for a while now. Dynamat is wayyyy expensive for the amount you get. Brown Bread (b-quiet.com) looks to be good stuff, almost the same effect that Dynamat has at a way cheaper price. Its also like 0.35lb per foot, not too bad. Brown Bread also has some foam stuff like v-comp and l-comp if you really want to spend some cash. I know some people on this forum have tried Raamat, but I don't know how good it is. If you really wanted to be cheap you could buy insulting stuff from home depot.

Is it true that the cheaper sound dampening stuff gives the car a tar smell? Like, from the asphault based dampeners compared to the vynl based ones.

[kandyflip445]

Don't get Fatmat. I got 2 rolls of it for a 120 shipped (100sq/ft) but it took FOREVER for it to get here. I tried CC first and then their paypal account froze. Finally got that refunded and sent a MO in and then it took ANOTHER month. When I got the stuff though I put 2 layers in my trunk floor and it quieted down the exhaust noise pretty well. I was gonna do under the carpet but the damn padding from the carpet is stuck to the floorboard so I'm gonna wait till I get a new carpet like Makoto did. If you have a hatch under the rear seat cushion there is a little piece of sound deadening material. It's like thick styrofoam or something and that "type" of sound deadening is better for the floor but it also costs more. On out cars it's better to get the spray on type for the doors because getting on the inside of them is a pain in the ass. Take the window out and everything else and spray. I used the sheet stuff cause I had a lot of it. Actually I still have a full roll for when I get a new carpet. Make sure you don't throw any for the plastic away behind the interior panels. Unless you seal those areas that were sealed by plastic then they will make more noise. If you have a sunroof it would help to get a new rubber seal. Also I don't know about other 240's but on the front of the hinges the rubber is gone, letting air get into the drain tubes and go through the car. There are vents that vent to the outside air too. There is a thread about "Look what I found in my 240" in the little pocket behind the rear panels on the side. If you reach down and toward the inside of the car you can find this vent with a rubber flap. I just sealed the pocket off with some deadening. NOT THE VENT. Just the area. Oh and if you search around and find any site that tells you to use carpet padding in the empty areas. DON'T DO IT. It will just hold moisture in and smell like ass when it rains a lot. I had to rip all that shit out when I did it. Um, I have yet to do the headliner but when I do I'll get back to you on that. If you have any questions just ask.