rottweiler68

Just ordered new ACC carpet with mass backing and am unsure if that alone with the jute pad is sufficient or should I also add Dynamat when installing?

I am unsure if #1 it's overkill and #2 if the carpet will even sit right or be to bulky with all that.

Have never done carpet before so looking for some ideas on this.

Thank you!

Chuck

Neil350

iTrader: (1)

That padding is pretty thick, I am doing it on my GTA now. I skipped doing the floors with dynamat type material and plans to do the doors. It seems if you wanted to do the floors, order the carpet sans the mass backing and do your own sound deading on the floor. I have the same fear as you, with mass backing it seems the carpet would not lay right.

TylerSteez

iTrader: (3)

I put dynomat in certain areas like above where the exhaust is before putting in my mass backing ACC carpet and I'm not too happy with how it came out, sounds kind of crinkly when I step into the car. I'm contemplating redoing certain areas of it. But don't let my experience discourage you from it, I've seen pics on here of other member's dynomat jobs and they did a great job with it.

rottweiler68

My plan was not to Dynamat at all but wanted others opinions too, so thanks for your insight!

rottweiler68

Thanks for the feedback!

87v6Bird

iTrader: (1)

On both my cars, I have a layer of the foil-backed rubber Dynamat topped by a layer of Dynapad (which is a multilayer foam) with the mass backing on my carpet. It's definitely a tighter fit to get all the interior panels and center console installed but it's doable. Bottom line, I noticed a great improvement in the interior noise levels of my cars.

In the 87, I originally started with just Dynamat. Interior noise levels were reduced but not as much as I'd really hoped. Later on, I got the 89 and pulled the carpet to repair the rusted floorboards. I went with both Dynamat and Dynapad when I put the carpet back in. The interior noise levels on the 89 were noticeably better than on the 87. When I decided to replace the carpet in the 87, I got replacement carpet from ACC with the mass backing and I also put in a layer of Dynapad. It's a tight fit but I got everything back in. Interior noise levels in the 87 are now as good as the 89. I'll have to look, I have pictures somewhere.

Also, another tip is to look into Dynamat and Dynapad alternatives. From what I've seen there are cheaper, equal alternatives. Just don't go for the asphalt roof sealer some people suggest.

rottweiler68

Great info, thank you! I've seen that roofing stuff on youtube from lowes/walmart and wondered lol.

tomsaddy

iTrader: (4)

One of the things that the dynamat does that foam doesn't is dampen vibration in the sheetmetal. If you're using both, you don't have to use dynamat everywhere, just in the big flat sections.

A good way to tell is to tap on the surface your going to cover. If it sounds like your hitting a drum, then it would really benefit from the dynamat to stiffen the panel. Curved and integrally stiffened areas, like the trans tunnel, aren't as prone to vibration so the foam alone will be more effective there.

I used dynamat on mine, although not 100% of surfaces. I haven't decided yet which additional insulation to use.

mantaguy

iTrader: (5)

You really don't need it,the jute and the mass backing is pretty thick already.
Some people like it .some don't.

jharrison5

I guess it's all comes down to what you're looking to do with your car. I'm not worried about added weight, since my car will be a cruiser and not a racer.

I used some stuff called Fatmat I found on ebay and it really helped knock the "tin can" sound in my camaro. I actually liked it so well that I put some in my daily driven pickup and it made quite a difference when all the windows are up.

rottweiler68

Mine is just a cruiser as well. Is this Fatmat installed under the jute and carpet with mass backing? Thanks!

mantaguy

iTrader: (5)

Yes , it is installed under the carpet,If your car is just for cruising and it's so noisy use it ,If not, Don't waist your money.

scooter

iTrader: (11)

This is 100% accurate. You only need 25% coverage on flat panels with Dynamat and the like.

In my car I used Fatmat ~25-50% coverage on all the flat places on the floor, then I put a layer of Mass Loaded Vinyl in addition to the mass backed carpet. I think it made a huge difference in the interior sound reduction. I haven't done the doors or the B pillars yet though, I am hoping to get close to what the sound level reduction would be out of a new car. I also did the roof with Fatmat, again 50% and I put butyl rope in the cracks if the reinforcing bits to the flat panels, that made a big difference in the vibration reduction up there compared to just the fatmat on the flat surfaces.


**EDIT, should be 25%, not 50, sorry***

jharrison5

Yup it came in a big roll and I just cut it to fit. I covered the entire floor because i didn't know any better, but when I did the pickup I used it sparingly on the flat areas.

Here's the link to my build with the pics of the mat installed.

https://www.thirdgen.org/forums/memb...ml#post6024079

87v6Bird

iTrader: (1)

A few pictures of the deadening materials I've put in my cars. As others have noted, you don't need so much coverage with the Dynamat. I didn't know better at the time. Hope they show for everyone.

ktthecarguy

Hi there,
There is also a product called Thermo-Tec available at Walmart, part #14620, in a 36" X 60" sheet. I bought 2 sheets and did the whole car, including a couple panels in the roof above the headliner. It's very effective, and way cheaper than dynamat.

rushtk

Do not buy the the crap from lowes or home depot if you live in hot climates!!! The stuff after time becomes brittle and you lose the efficiency of it and then need to clean up the mess. We restored our 99 tahoe 4 dr last summer and at 60 mph the inside db level was 101, spent 2k on a thermal floor sealer and Dynamat products (headliner came out also) and it went to 73 db at 60 mph. After weather stripping is done it will be less. The inside cab temp was also regulated better! We are restoring my sons soon to be first car (92 Z hard top) now and it is completely stripped out and we will do the same but with a company called Second Skin.

mantaguy

iTrader: (5)

Yes ,it came with Mass Backing from the factory and it is a upgrade on replacement.

ScarabChris

I used this product instead of Dynamat. It's a fraction of the cost. They make it in wider rolls too. It's a little thinner than Dynamat but not by much. I noticed a little difference in road noise after lining the floor of the car with this. Pick up a few rolls at your local Home Depot.

Sweatlock

iTrader: (1)

grover85

iTrader: (1)

Wish I could go back in time and not put it in. Scraping it out and it sucks