TeeJayHoward

While adding Dynamat or similar everywhere will work, it's not the most efficient method of quieting a car. In fact, it's almost the LEAST efficient method of doing it. Anything more than 25% coverage does almost nothing except add weight. Dynamat (or equivalent) is actually just the first layer of a three-layer process. It's sole job is to keep metal from vibrating. The second layer is a closed cell foam which separates the dynamat from the mass loaded vinyl. Sometimes car manufacturers use juke for this purpose instead of CCF. The mass-loaded vinyl is the third layer, and is what blocks most sound. This is why car carpeting has that rubber back side to it - it's functioning as cheap MLV. You can get a quieter car by strategically adding Dynamat to locations that "ring" when you tap them with a plastic hammer. I don't think I'd ever add more than that. If it's still not quiet enough for you, cover your floor and doors with CCF then MLV. The end result will weigh approximately the same as pure Dynamat, but will be several dBA lower. (It also generally takes several hours longer to do, and requires a lot of experience to do RIGHT.)

shadow993

[quote=TeeJayHoward]While adding Dynamat or similar everywhere will work, it's not the most efficient method of quieting a car. In fact, it's almost the LEAST efficient method of doing it. Anything more than 25% coverage does almost nothing except add weight. Dynamat (or equivalent) is actually just the first layer of a three-layer process. It's sole job is to keep metal from vibrating. The second layer is a closed cell foam which separates the dynamat from the mass loaded vinyl.

So ... I read mixed reviews on dynomat, so I'm going with 1/4 closed cell foam on fender liners. If no improvement from fender liners only, I'll add it to the rear deck and back seat area.

Ive put it on front fender liners only and it's added some reductions. The real test the back, bc that's where I get a ton of road noise.

I'll post details after I finish.

Carlos4S

shadow993

I bought this.... good enough for gas monkey and good reviews.

TeeJayHoward

The function of CCF like the above is typically to prevent two pieces that normally rattle against each other from touching, similar to cloth tape. Think dashboard area - it's like the stuff that sits on top of the blower motor and connects it to the venting tubes. I've never used it in other situations before. I'm interested to see the results! The CCF I'm talking about is typically very thin and does almost nothing for sound deadening on its own - It just holds the MLV apart from the vibration dampener. Most of the actual deadening comes from the MLV, not the CCF.

shadow993

I installed CCF on fender liners, inside of the car from the back of the seats to the rear window, and on inside rear fenders.

I did the front fender liner first, the biggest difference was there. It's like there was zero noise in front of me ... even with worn tires.

As for the back... running catless X-pipe so a very loud exhaust when not cruising.

Porsche used a few pieces of deadening type of material here and there to stop vibrations. I was shocked to see nothing on the rear deck.


The CCF did improve as mentioned before. It's more of a muffled sound, and less engine noise at idle, but not a drastic difference. However there is a benefit and I would do it it again.

The issue is... I stopped at the back of the seats. Now I'm hearing road noise from the bottom of the rear seats and rear floor. I don't think you can achieve desired results without doing the entire car.

Also... I used 1/4 CCF, and it takes a little bit of massaging to get all trim pieces back on.

gsxrjjordan

This thread is great! I was just thinking about doing some dynamat-like adhesive (I use Damplifier Pro) and Luxury Liner Pro that I had laying around from doing my Hummer, and this is great discussion.
Like some others, I have catless x-pipe exhaust and don't mind the engine noise, but would love to get rid of some more road noise. Doing the fender liners and interior behind the doors seems like a no-brainer, but I appreciate the feedback about needing to do the floor/rear seat area, and probably the firewall, for max effect.

Would love to see more updates from others tackling this. When I did my meth system install I had the rear torn apart from the rear seats back and it wasn't too tricky, but I can see pulling up the seats and carpet being a big more of a pain.

911.Forever

Yes, a definite decrease in road noise. A no brainer from my perspective but it's nice to see the dialogue on options.

Needsdecaf

Following up on this. Road noise from the tire scream on the concrete pavement here is enough to almost keep the car off the highway. It's a constant 79-81 dB at freeway speeds. Ouch.

Any issues with putting the foam in the wheel wells in the TX heat? You're probably even hotter than us up there. I'm not looking to make the car "quieter" overall, I just want to get rid of the tire noise.

Rig.Stunts

Good idea, I may try the front fender liners with Soundskins

My Road noise was greatly reduced after doing the doors. Stereo sound improved drastically also!