Soundproofing Road Noise

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sgrip65

sgrip65

66 Dart GT 273, 65 Dart GT 273 HiPo
FABO Gold Member
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Members, First a story. I built a 66 Dart GT a few years ago that has a lot of Road Noise in the cabin. I am now working on a 65 Dart GT, and I don't want to make that same mistake. What are the best Automobile sound proofing materials, where would be the best placement in the vehicle, and what about between the doors and window cavities? Currently, the car is barebones, with no glass, dash, or any interior. I have all options available. I will be using the stock 65 V8 HiPo resonated exhaust, so I understand that sound, but, I guess the question is there on the road noise. I appreciate any input. Thanks. sgrip65
 
I used a dynamat clone from amazon called Noico. It was a lot cheaper and the only difference seemed to be that the tin foil was thinner. I covered the floor, trunk, wheel wells and everything else I could stick it too. I put it behind the door panels too. Saw them do similar thing on Graveyard Cars. I used aluminum furnace tape from Lowe’s to cover seams as it is cheap. The stuff doesn’t adhere permanently till it goes through a few temperature cycles, then it is really stuck. It really quieted the car down a lot. I still like loud cars, but I am old enough I prefer the loud on the outside.

People use a lot of different things. Furnace duct insulation, shoddy pad, carpet pad, & all kinds of clever stuff. If you search forums here and the internet you will find a lot of info.
 
Mike69cuda said:
I used a dynamat clone from amazon called Noico. It was a lot cheaper and the only difference seemed to be that the tin foil was thinner. I covered the floor, trunk, wheel wells and everything else I could stick it too. I put it behind the door panels too. Saw them do similar thing on Graveyard Cars. I used aluminum furnace tape from Lowe’s to cover seams as it is cheap. The stuff doesn’t adhere permanently till it goes through a few temperature cycles, then it is really stuck. It really quieted the car down a lot. I still like loud cars, but I am old enough I prefer the loud on the outside.

People use a lot of different things. Furnace duct insulation, shoddy pad, carpet pad, & all kinds of clever stuff. If you search forums here and the internet you will find a lot of info.
Click to expand...

Thank you for taking your time for the advice. Yes, every square inch is open for this project. What about insulating between the underside of the roof and the headliner? Good info. Thanks. sgrip65
 
I'm starting a complete go-through on my car, and soundproofing is high on the list. Dynamat is a really good, effective product but expensive. There are other materials that will just about do the same job but are lots cheaper. I recommend putting it anywhere there is a flat surface to accept it. I will be doing the floors, firewall, inside the doors, headliner, inside the trunk, and the undersides of the hood and trunk lids.

The foil tape idea is a good one and it really works. I did it when I replaced the carpet with vinyl in my truck. I used some really cheap insulating sheets, and with the foil tape I had the whole floor done in short order.
 
halfafish said:
I'm starting a complete go-through on my car, and soundproofing is high on the list. Dynamat is a really good, effective product but expensive. There are other materials that will just about do the same job but are lots cheaper. I recommend putting it anywhere there is a flat surface to accept it. I will be doing the floors, firewall, inside the doors, headliner, inside the trunk, and the undersides of the hood and trunk lids.

The foil tape idea is a good one and it really works. I did it when I replaced the carpet with vinyl in my truck. I used some really cheap insulating sheets, and with the foil tape I had the whole floor done in short order.
Click to expand...

Is there any "Crackle Effect" from the foil tape getting stepped on, or the silver sheet surface. Thank you for the advice. sgrip65
 
There is info on insulation for headliners around too. I didn’t pull mine out so I haven’t got to that yet. It is different stuff I think, lighter and uses other materials. Detroit Muscle sells some dash insulation kits.

I did a lot of research on sound proofing, but found it hard to implement in a car. As I understand the idea is to use different densities of materials sandwiched. When the sound wave is traveling through a low density (like foam or Fiberglas insulation) and it comes to a higher density material (like fiberboard), part of the sound is reflected back at the interface of the materials. I believe the magnitude of the reflection is based on the ratio of the densities. If you were to have multiple layers, the amount of sound would get smaller and smaller as it went through the layers. Some of it would be absorbed and some would be reflected. Some of the materials are pretty pricey and it looked a little dicey, so I didn’t pursue it.

Well, I have probably told you more than I really know. There is a lot of good info out there. I included a few pics of my dynamat install.

C1F95DA0-F63F-4415-940A-A5F9CAD249A2.jpeg


3C518BDE-B52F-4066-854F-1AB57176E3DF.jpeg


5B39354D-DBD6-4307-8750-8DE11A2E4C80.jpeg
 
Mike69cuda said:
I used a dynamat clone from amazon called Noico. It was a lot cheaper and the only difference seemed to be that the tin foil was thinner. I covered the floor, trunk, wheel wells and everything else I could stick it too. I put it behind the door panels too. Saw them do similar thing on Graveyard Cars. I used aluminum furnace tape from Lowe’s to cover seams as it is cheap. The stuff doesn’t adhere permanently till it goes through a few temperature cycles, then it is really stuck. It really quieted the car down a lot. I still like loud cars, but I am old enough I prefer the loud on the outside.

People use a lot of different things. Furnace duct insulation, shoddy pad, carpet pad, & all kinds of clever stuff. If you search forums here and the internet you will find a lot of info.
Click to expand...

Mike's, thanks for the info. I checked online and the NOICO mats come in 50, 80, and 170 mm thickness. What would be a good recommendation for thickness? Whatever. Wherever it will fit go as thick as I can? can? Just wondering, generally, what is the typical thickness. Thanks again. sgrip65
 
No crackle effects from dynamat or aluminum tape. It is solid as a rock when finished. You can mold it around about about anything. If the dynamat foil rips, just tape it over. There are a few different dynamat clones, some of them are rubber-ish, some are made of roofing tar type stuff. I used the rubber type stuff. Buy it as thick as you can afford in the biggest sheets you can get.
 
I used some 80 and some 50 thicknesses. Didn’t try the 170, didn’t see it when I bought mine.
 
Mike69cuda said:
There is info on insulation for headliners around too. I didn’t pull mine out so I haven’t got to that yet. It is different stuff I think, lighter and uses other materials. Detroit Muscle sells some dash insulation kits.

I did a lot of research on sound proofing, but found it hard to implement in a car. As I understand the idea is to use different densities of materials sandwiched. When the sound wave is traveling through a low density (like foam or Fiberglas insulation) and it comes to a higher density material (like fiberboard), part of the sound is reflected back at the interface of the materials. I believe the magnitude of the reflection is based on the ratio of the densities. If you were to have multiple layers, the amount of sound would get smaller and smaller as it went through the layers. Some of it would be absorbed and some would be reflected. Some of the materials are pretty pricey and it looked a little dicey, so I didn’t pursue it.

Well, I have probably told you more than I really know. There is a lot of good info out there. I included a few pics of my dynamat install.

View attachment 1715275520

View attachment 1715275521

View attachment 1715275522
Click to expand...

Sounds pretty impressive to me. So, with regard to the ceiling, I boughtt my headliner and the insulation pad from Dante's. The insulation pad is, basically, upholstery batting. Some say, that insulating a car roof invites roof rot as warm air rises and condensate when it hits to cold steel roof. Having an insulation pad would trap this moisture? That is what I've read. Thanks. sgrip65
 
Mike69cuda said:
I used some 80 and some 50 thicknesses. Didn’t try the 170, didn’t see it when I bought mine.
Click to expand...
A guy could buy some extra and double it in suspect or obvious locations. Thanks. sgrip65
 
No experience on the headliner condensation. Doesn’t sound right though, since the whole point of insulation is to isolate the two temp environments. Every house is insulated and the walls don’t ooze water. I wonder if you could isolate from moisture with a sheet of plastic.
 
Seems to me that is used something less than 200 sq ft plastering it everywhere. Even put it in my spare tire hole. Bought some of that stretchy speaker box carpet and carpeted over it in the trunk since the tin foil looked kind of goofy.
 
sgrip65 said:
Is there any "Crackle Effect" from the foil tape getting stepped on, or the silver sheet surface. Thank you for the advice. sgrip65
Click to expand...

No, there is no crackle that I can determine. Although, I need to be honest here. This is in a 94 TCD 3/4 ton which is pretty noisy any time it's running. And this is under some really heavy vinyl mat, like almost too much to bend into shape. And I can't hear for ****. But I wouldn't hesitate to recommend this stuff to anyone.
 
I just ordered the 80mm 2pack from Amazon. Two 36 sq. fr for around 130 bucks...free shipping. Beats the noise. Worst part, I need to do my 66 by stripping the interior back out. Day at a time. Thanks for all the advice to all. sgrip65
 
I used a product called Hush Mat and covered every area I could reach including under the headliner and under the door panels. It was expensive and added weight, but the heat and noise coming up through the carpet has been cut way down.
upload_2019-1-14_4-53-53.png
 
sgrip65 said:
Members, First a story. I built a 66 Dart GT a few years ago that has a lot of Road Noise in the cabin. I am now working on a 65 Dart GT, and I don't want to make that same mistake. What are the best Automobile sound proofing materials, where would be the best placement in the vehicle, and what about between the doors and window cavities? Currently, the car is barebones, with no glass, dash, or any interior. I have all options available. I will be using the stock 65 V8 HiPo resonated exhaust, so I understand that sound, but, I guess the question is there on the road noise. I appreciate any input. Thanks. sgrip65
Click to expand...
Great info here
Sound Deadener Showdown | Your Vehicle Quiet
 
sgrip65 said:
Members, First a story. I built a 66 Dart GT a few years ago that has a lot of Road Noise in the cabin. I am now working on a 65 Dart GT, and I don't want to make that same mistake. What are the best Automobile sound proofing materials, where would be the best placement in the vehicle, and what about between the doors and window cavities? Currently, the car is barebones, with no glass, dash, or any interior. I have all options available. I will be using the stock 65 V8 HiPo resonated exhaust, so I understand that sound, but, I guess the question is there on the road noise. I appreciate any input. Thanks. sgrip65
Click to expand...

For the "cymbal" effect.
It's butyl, not asphalt.
A dab'll do ya.
https://www.amazon.com/dp/B0751G6TMV/?tag=joeychgo-20
71%2BvVU%2BA5PL._SL1500_.jpg



For heat, everything else.
https://www.amazon.com/gp/product/B016QUS1YE/?tag=joeychgo-20

You can spend more and weigh more, but why?

https://www.amazon.com/gp/product/B016QUS1YE/?tag=joeychgo-20

Car Insulation - 4' x 50' Roll (200 Sqft) Sound Deadener & Heat Barrier Mat - Automotive Lightweight Thermal Insulation
by Carinsulation.com
51FyiMuyh6L._AC_US218_.jpg
 
I used "Lizard Skin" inside the car and DUI overhead and on the firewall . the underside is painted and clear coated because it's easier to keep clean . they are both GREAT products . Do NOT use the products from the home center ! Most are asphalt based and you can't get the smell out . You don't need undercoating unless you drive your Mopar year around .
 
BrianT said:
I used a product called Hush Mat and covered every area I could reach including under the headliner and under the door panels. It was expensive and added weight, but the heat and noise coming up through the carpet has been cut way down.
View attachment 1715275582
Click to expand...

Hi Brian. What did you use on your door and window access openings? Is that a plastic or additional mat insulation. Thanks. Jerry
 
BrianT said:
It's the same Hush Mat product used elsewhere
Click to expand...
Hi Brian, so the hushmat is not too thick under the door panel? That is good. My original door cavity seal was simply plastic taped on. Thanks again.
 
383Scampman said:
I used "Lizard Skin" inside the car and DUI overhead and on the firewall . the underside is painted and clear coated because it's easier to keep clean . they are both GREAT products . Do NOT use the products from the home center ! Most are asphalt based and you can't get the smell out . You don't need undercoating unless you drive your Mopar year around .
Click to expand...
Second Vote for Lizard Skin. I sprayed their Thermal barrier and Sound barriers on a friend's 67 Mustang, and I was very impressed. Going forward, it is all I plan to use.
 
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