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I don't know if this would be better in the interior and detailing segment, but I figured this would be a better place to reach those of you dealing with classic cars. I'm looking at Dynamat for my 66 Impala, but noticed that Late Great Chevy offers AcoustiShield pre cut kits for various vehicles. Their kit utilizes strips of Dynamat versus how I was going to cover entire surfaces with it. Either I was pursuing a wasteful strategy, or they are skimping on material. I also intended on using a top layer, whereas theirs uses their top layer as well. Cost is about the same either way. Can anyone comment as to the efficacy of the AcoustiShield kits versus doing it yourself with rolls of Dynamat? Thanks.
There are cheaper products than Dynamat out there that do the same thing. I've used Noico on my rides before, but I think they've increased their price lately. There are plenty of butyl options out there. Just pay attention to the thickness and square footage when comparing prices.
The old school of thought was that you need to cover every square inch of the car in sound absorption material. That isn't really the case. You simply need to place the material in areas that are prone to transmitting noise, and strips of the material will suffice in dampening noise.
Covering the whole interior in any kind of Dynamat type material is just a waste of money and adds unnecessary weight to the car. Dynamat is a sound insulator, not so much a temperature insulation. It takes the tinnyness out of sheet metal, so you only need enough to do that, then put down some actual insulation to keep heat out of the interior.
I like Second Skin damplifier, used it on the wagon after replacing the floor pans. Reasonably priced, seems to work well for both sound deadening and heat refection.
And no, you don't need 100% coverage for good results...
Used (BOOM MAT) in my bird. From firewall back, my reason was big cam/ header's/ dumped exaust. Yes I added weight , and the doors actually "clunk" when you close it. But it was a night and day difference between them. I really didn't mind driving a Nascar on the out side/ mild hot rod on the inside...
I went with a layer of Lizard Skin sound deadening with a layer of clear coat on top of that to give a smooth clean surface for the aluminized adhesive rubber to stick to.
As noted above, it is very true that these products don't do much for hot / cold insulation. The rubber coatings add mass to the sheet metal to lower the resonant vibration to a less annoying frequency and achieving good improvement here does not require complete coverage. As he said, its to get rid of the "tinnyness".
Lizard Skin thermal and sound barrier spray in for my '69 Chevelle. Wire wheel prep, etching primer, and then tape/shoot the Lizard Skin. My car was incredibly rust free. Only need to replace the panel below the rear window as it had a vinyl top.
Dynamat and the like are vibration dampers. They convert vibration into heat so the panel doesn't create sound, you only need ~25% coverage on flat panels to accomplish this strategy, anything more is a waste of time and money. On top of that you need mass to stop road and other transmitted sound.
You can read all about it here sounddeadenershowdown.com
Plus one on sound deadener showdown. Great site that explains what you need to properly tame unwanted noise.
Tldr their method is 25% coverage dynamat or similar, cover that with 100% coverage of closed cell foam, then cover that with mass loaded vinyl. Its effective, I have used this combination in the past.
sounddeadenershowdown.com -- went to site --- but appears to be some good info there.
We are Closed as of February 1st, 2019 for Retirement.
wow, didnt' realize don had closed up shop. good news though is all the types of product that he recommends (closed cell foam and mass loaded vinyl) are readily available. His deadener (i think he calls it CLD tiles or something?) was pretty darn good though.
Not directly on topic but relevant to the discussion - one of the best things we can do to quiet things down and create a more refined/sophisticated experience inside the car is to do what's possible to stiffen up the frame/unibody. Many of us in the forum are swapping older cars/trucks. The stiffness (torsion and bending) of older vehicles is nothing close to what newer cars have designed into them -- you can thank safety regs. The older stuff bends and twists more easily - and that allows things to move. And when stuff moves, it usually makes noise. Over decades, things loosen up and move more and more. If you improve in that area before you start damping/insulating - things get even nicer. With the added benefit of having a better handling vehicle as the suspension can act on its own, as opposed to having the frame/unibody be PART of the suspension. fwiw on a rainy, cold morning.
Not directly on topic but relevant to the discussion - one of the best things we can do to quiet things down and create a more refined/sophisticated experience inside the car is to do what's possible to stiffen up the frame/unibody. Many of us in the forum are swapping older cars/trucks. The stiffness (torsion and bending) of older vehicles is nothing close to what newer cars have designed into them -- you can thank safety regs. The older stuff bends and twists more easily - and that allows things to move. And when stuff moves, it usually makes noise. Over decades, things loosen up and move more and more. If you improve in that area before you start damping/insulating - things get even nicer. With the added benefit of having a better handling vehicle as the suspension can act on its own, as opposed to having the frame/unibody be PART of the suspension. fwiw on a rainy, cold morning.
That makes perfect sense! A win-win. So the process of resto-modding with subframe connectors, torque box stiffeners, etc. should go a long way towards quieting the ride too.
Combining all that with the above stick-on sound deadeners is a real solution to NVH issues.
Im using a combination of fatmat, EZ cool. EZ cool lightweight foil backed, on roof and vertical surfaces, I dont like it for floors unless its a second layer. Fatmat on floors, firewall. Fatmat partial coverage on backside of door skins and inner quarters.
Also shot the entire bottom of car while on rotisserie, epoxy primer, UPOL bedliner( taped off frame rails), urethane chassis black. Shot the footwells inside with bedliner.
I used the SDS method on my 85 IROC and was amazed at how much it improved the driving experience. The MLV is heavy stuff so if you are weight conscience, it's probably not the best solution for you. All told, I added 240lbs to my car with that system.
Dynamat and the like are vibration dampers. They convert vibration into heat so the panel doesn't create sound, you only need ~25% coverage on flat panels to accomplish this strategy, anything more is a waste of time and money. On top of that you need mass to stop road and other transmitted sound.
You can read all about it here sounddeadenershowdown.com
Yeah and new cars are examples of this, you can find squares of deadener/dampener under the carpts, it's for NVH. My 2010 had a lot of V, so I did some squares in the trunk and under the rear seat.
In addition to Dynamat (or equivalent), which is NOT insulation, you need to use some sound absorbing insulation.
I used Dynamat, 3M Thinsulate in varying thicknesses, mass loaded vinyl, jute, carpet and even spray foam in a couple spots and my car 1966 Chevelle is very close in sound quality to my wife’s BMW.
Not directly on topic but relevant to the discussion - one of the best things we can do to quiet things down and create a more refined/sophisticated experience inside the car is to do what's possible to stiffen up the frame/unibody. Many of us in the forum are swapping older cars/trucks. The stiffness (torsion and bending) of older vehicles is nothing close to what newer cars have designed into them -- you can thank safety regs. The older stuff bends and twists more easily - and that allows things to move. And when stuff moves, it usually makes noise. Over decades, things loosen up and move more and more. If you improve in that area before you start damping/insulating - things get even nicer. With the added benefit of having a better handling vehicle as the suspension can act on its own, as opposed to having the frame/unibody be PART of the suspension. fwiw on a rainy, cold morning.
I fully agree with Michael on this concerning unibody cars. They're as stiff as a wet noodle without subframe connectors welded in.
This is an incredible discussion about sound deadening to improve our older, noisy cars. I've got a project, 1991 Mustang coupe (Project "Hole in the Head") with an LS376/480 and a T56 Magnum that is wearing the full Maximum Motorsports catalog of suspension components. A lot of these components will transmit more NVH to the cabin of the already noisy, rattle filled, tin can sounding car. I've been adding non-traditional, "sound deadening" material to the floor as well as cut squares of it to the sides of the car.
Quick Roof that I purchased from Amazon.
Peel and Seal that I purchased from Lowes. I actually like working with this better than the Quick Roof. They appear to be the same, tar like, aluminum backed material. The aluminum is different and, obviously the P&S comes in a much bigger roll. That's 30.54 pounds for a complete 100 square foot roll in the box.
I did a lot of internet research on these roofing materials before actually using them. They got great reviews by car guys that have used them including southern guys in 100F summer temperatures. No tar smell that many skeptical people were scared of.
Some of those other foam type products that you guys are mentioning sound like they could really bring the NVH level down in my car.
02-11-2021, 09:30 AM
Classic car insulation 
