anyone use Dynamat/ Be Quiet to deaden exhaust noise?

[Galavoxx]

There are some threads regarding the use of dynamat but none of them address my problem. I recently installed a Magnaflow with 2" exhaust pipe from the tip of the cat to the muffler. After watching the vid in this post:

http://www.yarisworld.com/forums/sho...ight=Magnaflow

the sound didn't seem unreasonable.

So basically, the exhaust is too loud inside the car and I'm wondering how much some dynamat will help reduce the exhaust noise? And has anyone figured out how much is needed to cover the rear tire/trunk area?

[bigsky2]

For the spare tire area / hatch floor, I think you need at least 8 sq. ft. to cover just the floor.

To take care of the upper hatch area including the inside of the hatch lift, probably another 6-10 sq. ft. depending on how much material you wish to apply.

A friend of mine has also suggested spraying the wheel well with a special material that will also reduce road noise. But this requires taking out your wheels and covering your suspension. Bit more work, and I cannot guarantee the results as I've not done this myself yet.

I say get 25 sq. ft. and start with the trunk area/spare tire area.

[spkrman]

do the floor from the B pillar back with 2 layers + a layer of padding over that (closed cell foam preferably) and that should deaden very well, along will kill alot of ambient road noise.

it would take approx 30 sq feet to do that, and as stated above, however much you get... start with the spare tire/trunk area.

[Violin]

Dynamat is not so much intended to be a sound insulator as it is a way to dampen the motion of metal panels in the car. I used it in my door panel where the speakers are and also in the hatch lid to eliminate that el cheapo *ting* sound when it closes.

For road noise, I got some 1/4” thick foil covered closed cell foam and put several layers over the back wheels (inside the panel) and a single layer in the hatch area under the spare tire. I glued it down with PL Polyurethane construction adhesive. I found a 4' x 10' roll for about $40 or so. I wish I could remember where, but it's been a while. It is heat resistant enough to use on the firewall.

[Galavoxx]

Originally Posted by Violin

Dynamat is not so much intended to be a sound insulator as it is a way to dampen the motion of metal panels in the car. I used it in my door panel where the speakers are and also in the hatch lid to eliminate that el cheapo *ting* sound when it closes.

For road noise, I got some 1/4” thick foil covered closed cell foam and put several layers over the back wheels (inside the panel) and a single layer in the hatch area under the spare tire. I glued it down with PL Polyurethane construction adhesive. I found a 4' x 10' roll for about $40 or so. I wish I could remember where, but it's been a while. It is heat resistant enough to use on the firewall.

I've not used Dynamat but from what I've read, I've always thought it was used to dampen sound of any kind. Road noise, panel vibration, etc. But this foil covered foam does a better job? Do they offer different levels of dampening with this stuff? From what I recall, Dynamat and other similar products even give noise reduction numbers in terms of decibals. Now I'm confused. Anyone else have anything to say about this.

[Violin]

What the dynamat does is keep the metal panels from flexing. That will help to deaden road noise, but its not cheap. The foam is far cheaper and does a good job of insulating non-critical areas - those without drivers mounted in them. Using both like spkrman suggested is even better. If you want to go all out remove the seats and carpet and insulate the entire floor.

[spkrman]

the dynamat will block certain freq's, closed cell foam others, its really the best way to go.

dynamat adds mass to the panel, lowering its resonant frequency so that it cant rattle... your floor doesnt rattle anyway, and dynamats usefulness in that application is minimal at best... but its great for road noise - it blocks most of the high pitched stuff while sealing the car tight, the closed cell foam blocks the high to mid freq's and provides another layer of heat insulation.

But, if your on a tight budget and can only do one - go with teh foam.

[Galavoxx]

Sounds good. I think I'll wait until I can buy both the foam and the dynamat. That sounds like the ultimate way to go. Thanks guys.

[spkrman]

yea its definitely the way to go to not only block road noise, but block everything else!

My 99 monte carlo had:

on the floor and doors:
3 layers of liquid deadener (fairly thin layers)
2-3 layers of mat deadener
a layer of foam

The roof had 2-3 layers of liquid deadenor.

There were also various cavities filled with expanding foam.

It was so quiet I had to crack the window to hear what was going on outside lol.

[Speedz]

Originally Posted by spkrman

yea its definitely the way to go to not only block road noise, but block everything else!

My 99 monte carlo had:

on the floor and doors:
3 layers of liquid deadener (fairly thin layers)
2-3 layers of mat deadener
a layer of foam

The roof had 2-3 layers of liquid deadenor.

There were also various cavities filled with expanding foam.

It was so quiet I had to crack the window to hear what was going on outside lol.

Using foam is inexpensive but make sure there is not moisture before applying it as those foam will trap those moisture and will rust the bare panel over a period of time....

I'm planning to get some inexpensive sound deadening mat and cover over rear boot to reduce some road noise...