12v Nick

It helps a ton.

The Mass-Loaded Vinyl is the heaviest, a full coupe treatment front to rear probably has 35lbs of that. The CLD material is around 15lbs and the spray on is maybe 5lbs.

So, maybe ~55lbs total.

BradB

I lined the inside of the plastic wheel well liners with Dynamat almost two years ago. It made an appreciable difference. Glad I did it.

planet

Can you explain how? Do you have photos?

BradB

Not much to it, really. I removed each wheel for ease of access. Removal of the front and rear wheel well liners is very simple and quick. I then applied the sound deadening material to the largest flat spots on the back side of the liners. (Per the instructions I warmed the surfaces with a heat gun and then used a small roller to apply the material) I chose areas that made extra noise when I tapped it with my finger. My goal was to reduce the loud sounds made when gravel and stoned hit the liners. That's what really annoyed me and made the car feel "cheap". The difference has been quite noticeable.

During some recent maintenance I checked the sound deadening and two years later the material is still holding tight to the liners with no lifted edges.

Front and rear wheel well liners...

fastdiablo

Nice work Brad! Great mod.

skynet

Brad, sounds like your mod was successful muffling loose gravel. Did it tone down tire 'roar'? The droning you can get on coarse roads?

BradB

Oh yes, I feel it did. Mind you, I could have done more regarding extra sound deadening coverage but the goal was stuff that hits the plastic liners (and there is a LOT!) not the tire roar which wasn't as much of an issue for me. But if that is your goal I would start here before you get into the big job with the interior as illustrated by others above.

planet

Thanks, Brad! Interesting!

malahhaor

I had the same issue in my 997.1. It was a DD and noise was too much even though tires were good.
Even Dynomat and Closed Cell foam just in the doors made a noticeable (to me) difference in absorbing the road noise. I was going to pull the entire interior and line the floor and wheel wells but had to sell the car before i got to it.
Some closed-cell foam i think will help allot in absorbing some of that high pitch road noise.

77tony

Way to go

OKB

sound deadening material is not meant to be sound blocking material. It does not and cannot block sound like a wall. it is applied to a surface to deaden vibration. Vibration causes most sound
If you look at the job 12v nick did on his floor, thats the intent of deadening material. If you would (I did) apply the material to the wheel well, where you took the plastic off of, you would get alot more sound deadening. You can do it inside, if you take the carpets out, and outside where you took the liners off.

budrichard

How fast have you driven your car?
At top speed, I have no idea of the forces generated in the wheel wells by air flow but I would be concerned if any of the material came off at speed.
For me, it is what it is, and without an engineering understanding of what's involved, I will live with it.-Richard

BradB

Just north of 150. No change in material adhesion over the last couple years.

ace37

The stuff is very sticky, and from the picture it's not on the same side as the wheel is so even if it came loose it wouldn't fall off the car.

991 Dreamer

Great thread. Where is the best place to buy the sound deadening material?