How many dynamat do I need?

[robvanderveer]

I'm planning on adding dynamat (actually, Silent Coal) to my DeLorean next week now that the seats and the carpets are out.

I will be convering the following sections:
- floor
- footwells
- center console walls
- rear upper firewall
- lower back wall and parcel shelf

I know a few of you have done this before. Could you please give me an estimate on how much m2 or sq. foot i need?

Thank you for your time.

[David T]

I'm planning on adding dynamat (actually, Silent Coal) to my DeLorean next week now that the seats and the carpets are out.

I will be convering the following sections:
- floor
- footwells
- center console walls
- rear upper firewall
- lower back wall and parcel shelf

I know a few of you have done this before. Could you please give me an estimate on how much m2 or sq. foot i need?

Thank you for your time.

Take it easy on adding sound deadening materiel. I don't know about Silent Coal but Dynamat is HEAVY. Most of the noise comes in from the floor and the rear bulkhead, some from the doors.

[robvanderveer]

Yes, I thought i would be. I'll start with doing the floors (and footwells) so I can get the carpet back in, and see about the rest later on.

Any idea how much I need? I was thinking about something close to 2 m2, which (according to google) is about 21 square feet. Should cost me no more than €75..

[jawn101]

Yes, I thought i would be. I'll start with doing the floors (and footwells) so I can get the carpet back in, and see about the rest later on.

Any idea how much I need? I was thinking about something close to 2 m2, which (according to google) is about 21 square feet. Should cost me no more than €75..

I don't remember exactly how much was used. Clint (vwdmc16) and I bought enough for us to do both of our cars, but he placed the actual order for the material.

Thought I'd share these pics again of how I did mine though, since we're on the topic. I did have to revisit this and cut away the areas under the seat tracks (between the bolt holes) because the extra height was causing the seat to bind.

http://dmctalk.org/attachment.php?attachmentid=27115&d=1399848625
http://dmctalk.org/attachment.php?attachmentid=27116&d=1399848626
http://dmctalk.org/attachment.php?attachmentid=27117&d=1399848628

[vwdmc16]

We each installed about 70 sq feet in each of our cars.

[NightFlyer]

Would you say it was worth it? Or would the time/effort/resources have been better spent elsewhere?

[jawn101]

Would you say it was worth it? Or would the time/effort/resources have been better spent elsewhere?

It was a lot of work for sure. The expense wasn't huge, and neither was the difference - but overall it was worth it. It isn't like driving a Lexus afterwards, but the job definitely lessened the "boominess" inside the car. One time I demonstrated what that meant to someone by putting a 20 gallon rubbermaid tub over their head and running a huge stand fan right next to it. That pervasive, echoing white noise cacophony is reduced hugely. But it's still always going to be kind of a loud ride.

I will say that all of the various noise reducing efforts I've undertaken put together have made a very big cumulative difference though. New padding under the carpet, low-current fans, updated relays, properly maintaining the blower motor fan, eliminating intake/exhaust/vacuum leaks, correct valve adjustment, making sure panels are properly aligned and not rubbing, putting vinyl tubing over all the lock rods inside the doors, strapping down any loose bundles of wires, the dynamat, etc. All those little squeaks and rattles and clicks and clacks and whooshes and whirs really add up. I don't miss them.

Edit: Almost forgot proper door seals and good quality, matching (if possible), properly inflated tires. Most of these things are just a question of keeping your car in good nick and reaping the various benefits that come from that. Some are a little more anal-retentive but still pay off just the same.

[NightFlyer]

It was a lot of work for sure. The expense wasn't huge, and neither was the difference - but overall it was worth it. It isn't like driving a Lexus afterwards, but the job definitely lessened the "boominess" inside the car. One time I demonstrated what that meant to someone by putting a 20 gallon rubbermaid tub over their head and running a huge stand fan right next to it. That pervasive, echoing white noise cacophony is reduced hugely. But it's still always going to be kind of a loud ride.

I will say that all of the various noise reducing efforts I've undertaken put together have made a very big cumulative difference though. New padding under the carpet, low-current fans, updated relays, properly maintaining the blower motor fan, eliminating intake/exhaust/vacuum leaks, correct valve adjustment, making sure panels are properly aligned and not rubbing, putting vinyl tubing over all the lock rods inside the doors, strapping down any loose bundles of wires, the dynamat, etc. All those little squeaks and rattles and clicks and clacks and whooshes and whirs really add up. I don't miss them.

Edit: Almost forgot proper door seals and good quality, matching (if possible), properly inflated tires. Most of these things are just a question of keeping your car in good nick and reaping the various benefits that come from that. Some are a little more anal-retentive but still pay off just the same.

That's a great explanation - thanks Jon :thumbup:

[vwdmc16]

I agree with Jon, It was worth it but it wasnt incredible as we were hoping, I should mention we doubled the material up in some sections like the floor and rear firewall, even the wheel wells too. My car still has considerable tire noise at speed but that is something I cant stop without getting better tires. Also just as powerful as the Dynamat material was the Jute insulation that I stuffed in the rear firewall corners as much as I could to dampen engine and tire noise, The Jute is far cheaper too.

It is really amazing and kinda frustrating that modern cars, even non luxury models can be so well insulated compared to ours even after all the extra material installed.

[jawn101]

It is really amazing and kinda frustrating that modern cars, even non luxury models can be so well insulated compared to ours even after all the extra material installed.

It's almost all materials science - Quiet Steel, improved laminated glass, composites, etc. Amazing doesn't even begin to cover it!

[DMCMW Dave]

Edit: Almost forgot proper door seals and good quality, matching (if possible), properly inflated tires. Most of these things are just a question of keeping your car in good nick and reaping the various benefits that come from that. Some are a little more anal-retentive but still pay off just the same.

One other thing to check - we see quite a few cars where the bottom edge of the rear glass is completely unglued. This lets in an astounding amount of engine noise. Easy to check, just open the louver and press down on the fiberglass, or go inside the car and press outward on the bottom of the glass.

[robvanderveer]

Thanks all, for these great contributions.

What did you mean by the seat runners 'causing the seats to bind'?


Rob

[john 05141]

Dag Rob,

When I replaced my carpets I did the same thing. Also exactely the areas as you plan to do.
It is not a difficult job to do, use the left overs to cut small pieces to cover the real wheel well.
You will need to trim the wooden wall as it will not fit anymore.

I started with 2 boxes, but that was too tight, I got a third one later.

But I said it here before, I really would not recommend using Dynamat.
This stuff is expensive, heavy and I can tell absolutely tell NO DIFFERENCE. In sound anyway. I hear it also insulated for heat from the road, but you and I do not have that problem here.

Will you be at Ed's open house next sunday?

Jan

[robvanderveer]

Bedankt, Jan.

I'll be using a competitor's brand: Silent Coat, about 1/3rd the price of Dynamat. I'm not doing this for sound isolation per se, but for removing the bath tub effect as jawn101 called it.

I wont be at eds this sunday.. Still too far to drive for my condition

[Rich_NYS]

I agree with Jon, It was worth it but it wasnt incredible as we were hoping, I should mention we doubled the material up in some sections like the floor and rear firewall, even the wheel wells too. My car still has considerable tire noise at speed but that is something I cant stop without getting better tires. Also just as powerful as the Dynamat material was the Jute insulation that I stuffed in the rear firewall corners as much as I could to dampen engine and tire noise, The Jute is far cheaper too.

It is really amazing and kinda frustrating that modern cars, even non luxury models can be so well insulated compared to ours even after all the extra material installed.

Would you give some more details about jute please? Sounds like something worthwhile to look into.

Thanks!

[kings1527]

Something to consider and some have more or less touched on it. I researched this pretty good last year when I did my interior.

Sound dampening material such as Dynamat cuts down on resonation. Think of it as a snare drum and how some musicians will put duct tape or something similar on the underside. Without anything to deaden the sound, the drum will resonate and reverberate pretty hard. With just a few strips of tape or whatever, it cuts down on the reverb (or inside our cars, the 'drum' effect). Kind of like how echo-ey a room in a house can be without any furniture. Once you add furniture to it, the echo is drastically reduced.

Dynamat works the same way. That being said, it doesn't have to cover every square inch of your car to cut down on the effect nor does it have to be perfectly spliced into the car. You can have giant sheets of it covering 50% of an area and it doesn't mean it'll be a 100% difference in sound if you were to cover 100% of the area. That's what the actual closed cell foam matting will do. That blocks out the sound and that stuff needs to cover every possible area that you're focused on, without any breaks in the material. The breaks in a good quality closed cell foam matting will let in sound. Spaces and breaks in installation won't matter with Dynamat.

So in short, 1) Dynamat to cut down on the reverb/drum effect. 2) High density closed cell foam matting to reduce sound.

[Rich_NYS]

So in short, 1) Dynamat to cut down on the reverb/drum effect. 2) High density closed cell foam matting to reduce sound.

In another thread I found this link: http://www.mcmaster.com/#sound-dampers/=rxv19o

Did you use one of these types?

[jawn101]

Thanks all, for these great contributions.

What did you mean by the seat runners 'causing the seats to bind'?


Rob

They didn't slide fore and aft smoothly anymore. The carpet was being pushed up into the tracks or something. Removing that small strip of dynamat allowed them to move properly again.


Would you give some more details about jute please? Sounds like something worthwhile to look into.

Thanks!

It's just thick natural fiber carpet padding. We wadded a bunch of it up and stuffed the hollow pontoons full of it - I frankly forgot all about that.

[David T]

They didn't slide fore and aft smoothly anymore. The carpet was being pushed up into the tracks or something. Removing that small strip of dynamat allowed them to move properly again.



It's just thick natural fiber carpet padding. We wadded a bunch of it up and stuffed the hollow pontoons full of it - I frankly forgot all about that.

In many cases just putting strips of the stuff is enough to get an effect. One more important thing to consider is the flammability and toxic smoke it can generate of anything you install into the interior of the passenger compartment.

[Rich_NYS]

I've read through a few threads on Dynamat and eDead.

Mark, Jon, Clint, Alex:

If you had to do it again, what would you do differently?

-Would you use Dynamat or eDead?
-How much Dynamat/eDead would you use and where?
-Would you use more jute and where?
-What would you use for closed-cell foam and where?

I hope this helps the OP....I know this is the info I'm lookin' for! :cool:

[NightFlyer]

I've read through a few threads on Dynamat and eDead.

Mark, Jon, Clint, Alex:

If you had to do it again, what would you do differently?

-Would you use Dynamat or eDead?
-How much Dynamat/eDead would you use and where?
-Would you use more jute and where?
-What would you use for closed-cell foam and where?

I hope this helps the OP....I know this is the info I'm lookin' for! :cool:

I'd personally put the resources into upgrading the audio system - even with a 'boomy' cabin, with the right kind of speakers properly staged/imaged and some good clean power, all you'd have to do to drown out the engine/road noise is turn up the volume :biggrin:

[Rich_NYS]

I'd personally put the resources into upgrading the audio system - even with a 'boomy' cabin, with the right kind of speakers properly staged/imaged and some good clean power, all you'd have to do to drown out the engine/road noise is turn up the volume :biggrin:

haha....maybe a subwoofer that takes up the entire trunk! :headbang:

[NightFlyer]

haha....maybe a subwoofer that takes up the entire trunk! :headbang:


https://www.youtube.com/watch?v=Yq3tVgKW9jI

[kings1527]

For my sound dampening (like Dynamat), I used 36.5 sq ft of this:
http://store.secondskinaudio.com/damplifier-pro/

For my noise barrier (really a closed cell foam), I used 36 sq ft of this:
http://store.secondskinaudio.com/luxury-liner-pro/

My installation of Damplifier Pro looks pretty hackish, to be honest. It just never needed to be perfect, really. But Jon's looks absolutely pro. But with the Luxury Liner Pro, I kept the sheets as mostly intact as I could. It's also very important to make sure that the closed cell foam is completely bonded with glue. That helps with the sound deadening. For the glue, I used the 3M Yellow Adhesive spray which is great stuff. Just be sure to spray it and let it sit for about 5 min or so. That way, it'll get super tacky and stick real well.

As far as what I'd do differently, I think focusing on the sound system itself is great advice. The more sound proofing material you add, the heavier the car becomes and less performance you'll get. I estimate that I added probably about 75 lbs or so by installing all of this (not including taking the old material out). Net gain was probably about 60 lbs give or take. Less performance, less fuel economy, etc.

I don't know if the end result was a night and day difference. But the timing of the project was perfect: new car insulation, new sound system, new repro carpet set and redyed interior along with NOS seat covers that I was fortunate to locate.

I also put material on the wheelwells near the rear speakers which was a total pain. I don't know if I'd waste time on that again. Just know that adding all of the material will cause an increase in height. You'll see it with your seats and reduced ability to adjust (like Jon mentioned) and you'll also see it when you put the center console back on (which is manageable). But I think focusing on putting in a great sound system is something to focus on, along with dynamatting the interior (decent amount) and closed cell foam (as much as practical). For the rest of my setup, I have a power amp located behind the bulkhead, 5.25" speakers in the rear, 3.5" in the dash, and the DMC CA sub in the cubby. Just that alone makes my system sound perfect for me and I'm fairly critical of my music. All of the model numbers are in my signature. I highly recommend using an amp even if you're only dealing with 3.5" and 5.25" speakers. It'll let the speakers run much more efficiently since it takes a lot of stress off of the head unit. It takes a lot of power to push a sub and it's more efficient to have the amp do all of that (including the speakers) rather than powering all of it off the head unit. Not to spin the thread off topic.

[jawn101]

But Jon's looks absolutely pro.

*blush*


I don't know if the end result was a night and day difference.

Spot on. Worth doing but don't expect the world.

[robvanderveer]

Indeed those are the proper questions, appreciated!


Rob

[john 05141]

If you can get it at 1/3rd of the price from Dynamat, you're on the right track!!
But a good advice form those looking to get the car quieter; get new doorseals!

The car with the heavy stereo is from Laurent, or was. Car is sold now and this "equipment" has been removed. I heard it in person, and was doubling as a seat masseuse at the same time.

Jan

[Rich_NYS]

I've been reading Dynamat is expensive, but it's ~138 for 36sq ft on Amazon, looks to be the lowest cost compared to eDead and Damplifier Pro.

[GS450-Junkie]

I have Dynamat. Did it make things quieter? Yes, somewhat. I noticed more so that it "tightened up" a hollow interior, I did notice less rattle and shakes and flexing in the interior compartments and interior tub as the car moves down the road.

As others said, I noticed a bigger difference once door seals were replaced, and the carpet foam in the back was replaced with SpecialTAuto's big ass rubber matting system.

Don't let people scare you about Dynamat being so heavy. People freak out when you add 20, 30, 40 lbs. to a car. I just don't get it. By that way of thinking, a Corvette that carries 50 lbs of groceries from Walmart, or hell, a younger kid as a passenger is no longer a Corvette because of the added weight. :rolleyes1:

[David T]

I have Dynamat. Did it make things quieter? Yes, somewhat. I noticed more so that it "tightened up" a hollow interior, I did notice less rattle and shakes and flexing in the interior compartments and interior tub as the car moves down the road.

As others said, I noticed a bigger difference once door seals were replaced, and the carpet foam in the back was replaced with SpecialTAuto's big ass rubber matting system.

Don't let people scare you about Dynamat being so heavy. People freak out when you add 20, 30, 40 lbs. to a car. I just don't get it. By that way of thinking, a Corvette that carries 50 lbs of groceries from Walmart, or hell, a younger kid as a passenger is no longer a Corvette because of the added weight. :rolleyes1:

The smaller the car the more weight matters. The passengers, fuel, and load becomes a bigger and bigger percentage of the total weight. Do the math. Get the weight of the car, add passengers and fuel and see what the total comes out to. Unless you have children driving the car, no load and you do not fill the gas tank you are ALREADY overweight according to what the gross is. Hot-Rodders use a rule-of-thumb. Every 10 lbs=1 HP. It is a LOT easier to reduce weight than to add HP, cheaper too. Also works when you use the brakes and turn the car. Colin Chapman, the fellow who designed the car's frame and running gear had a saying "Add Lightness". That is why you have heard of the name Lotus.

[GS450-Junkie]

I'm sorry... did you just use "Hot-rodders" and "DeLorean" in the same talk forum? :D

[kings1527]

I have Dynamat. Did it make things quieter? Yes, somewhat. I noticed more so that it "tightened up" a hollow interior, I did notice less rattle and shakes and flexing in the interior compartments and interior tub as the car moves down the road.

As others said, I noticed a bigger difference once door seals were replaced, and the carpet foam in the back was replaced with SpecialTAuto's big ass rubber matting system.

Don't let people scare you about Dynamat being so heavy. People freak out when you add 20, 30, 40 lbs. to a car. I just don't get it. By that way of thinking, a Corvette that carries 50 lbs of groceries from Walmart, or hell, a younger kid as a passenger is no longer a Corvette because of the added weight. :rolleyes1:

I think when you're dealing with a car that will barely dyno 100hp, you need all you can get. Particularly when you're talking about adding weight on a permanent basis. In my case, I'd say about 60 lbs was added. If you lift the radiator, condenser, and fan assembly, all three are very light even when together. Lifting the entire muffler, again, very light. The seats, miscellaneous interior, compressor, manifold, etc...none of those come close to 60 lbs and it says a lot about how weight plays into design. I'm sure Chapman would've freaked about adding on an additional 60 lbs to the car just for soundproofing material.

[NightFlyer]

I'm sure Chapman would've freaked about adding on an additional 60 lbs to the car just for soundproofing material.

Especially if it doesn't yield much in the way of noticeable benefit...

[Rich_NYS]

How about just replacing the old yellow foam with new closed cell foam...does that seem sensible?

[David T]

How about just replacing the old yellow foam with new closed cell foam...does that seem sensible?

I am not saying you can't add any weight, just do it smartly. A few strategically placed pieces of sound-deadening materiel can accomplish a lot. Yes, there are better choices than old, thick carpet padding. Carpet padding was never meant for sound-deadening anyway. It also contributes to the smells.

[kings1527]

Especially if it doesn't yield much in the way of noticeable benefit...

Exactly.


How about just replacing the old yellow foam with new closed cell foam...does that seem sensible?

That's actually a great idea to me. I think that would yield some very noticeable benefits. Again, not night and day but noticeable. The old stuff is hard to get out and does take a bit of work.

[vwdmc16]

Jon and I used an Off brand Dynamat like material, Think it was called Fatmax or something, Sounds like a horrible weight gain formula for starving children.

It was like about 60% the thickness of Dynamat pro so that was another reason to double it up but it was less than half the price so it really was cheaper to get. the 150 sq ft roll was less than 50 lbs and each car used half of it. If I were to do it again I would look into getting something like Lizard Skin to spray in the back corners of the firewall area. Id love to hire on a sound acoustics engineer to find a better more efficient way to dampen noise.

[robvanderveer]

The best way not to add weight to the car is not to bring a passenger. Sorry to say it so bluntly, but in my opinion the 20 kg or so doesn't really matter if you chuck in a 100kg driver and a 60-80kg passenger, not even counting the 25-or-so kilo's of 'junk' in the front booth (spare water hoses, spare coolant, tools, jack, spare wheel, power pack, should i go on?) and a fully filled gas tank,

In short, i'm not very worried about the added weight. I'm not going to carpet the entire tub with Silent Coat 4mm, i'll be doing a few critical sections only. I prefer getting out of the car after a long drive without a dizzy head over the top end power which i rarely use anyway (after all, it's not a hotrod)


Rob

[kings1527]

The best way not to add weight to the car is not to bring a passenger. Sorry to say it so bluntly, but in my opinion the 20 kg or so doesn't really matter if you chuck in a 100kg driver and a 60-80kg passenger, not even counting the 25-or-so kilo's of 'junk' in the front booth (spare water hoses, spare coolant, tools, jack, spare wheel, power pack, should i go on?) and a fully filled gas tank,

In short, i'm not very worried about the added weight. I'm not going to carpet the entire tub with Silent Coat 4mm, i'll be doing a few critical sections only. I prefer getting out of the car after a long drive without a dizzy head over the top end power which i rarely use anyway (after all, it's not a hotrod)


Rob

Excellent. Good luck!

[Rich_NYS]

At the very least, I'm going to replace the old yellow foam. Has anyone here used this?

http://www.mcmaster.com/#standard-sound-dampers/=rz9otf

[papanoel]

At the very least, I'm going to replace the old yellow foam. Has anyone here used this?

http://www.mcmaster.com/#standard-sound-dampers/=rz9otf

I've been doing some reasearch to dyanmat alternatives and found this http://www.b-quiet.com/ultimate.html
it is also butyl based and not asphalt based like others. I think i'm going to use that. They also have a thick heavy foam product that goes on top of the other material.

[robvanderveer]

There are over 100 products on that page, which are you referring to?


Rob

[lazabby]

Someone mentioned sound dampening material and noise barrier material. Are these something that can be used in combination and if so where would each go?

[kings1527]

Someone mentioned sound dampening material and noise barrier material. Are these something that can be used in combination and if so where would each go?

Sound dampening material (like Dynamat) lays down first, directly on the tub itself. Noise barrier material (like the old yellow foam padding, but much better stuff is available today) is laid on top of the sound dampening material. Then your carpets go on.

[Lenny]

I am not saying you can't add any weight, just do it smartly. A few strategically placed pieces of sound-deadening materiel can accomplish a lot. Yes, there are better choices than old, thick carpet padding. Carpet padding was never meant for sound-deadening anyway. It also contributes to the smells.

Where would "Strategically Placed" be to get the most (or least) bang for the buck?

[robvanderveer]

27249

Here's a shot of the stuff i ordered. It is more than enough. I didn't want to run out of sheets when i'm halfway. According to the courier the total weight is 21820 grams.

Can't install it yet, i need to clean the tub first.

[kobachi]

putting vinyl tubing over all the lock rods inside the doors

Go on...

[jawn101]

Go on...

Nothing too much to explain - open up your doors and disconnect the lock rods at one end. Slip some appropriate diameter vinyl tubing over them and re-connect. I don't remember the proper diameter, unfortunately. This stops the rods from banging on each other or on the stainless holes that they pass through at various points inside the door. Dampens a lot of rattles.

Actually now that I'm thinking about it, I had to be a little strategic with this process and do some rods by disconnecting them, some with a piece of tubing that was slit lengthwise. Tape the ends of the tubing so it doesn't slide down and interfere with any functional components or get bound up as the rods move back and forth. More of an art than a science :)

[robvanderveer]

Installation started. This is the 2mm Silent Coat. The rest will be 4mm Silent Coat Extra. Too bad i don't have the energy to finish it up. 275242752527526

[robvanderveer]

I finished putting all the stuff in under the seats and footwells. Seeing what i got left, i bought about twice the amount i needed. 27560 this is what i bought. 2x12 sheets of 4mm and 20 sheets of 2mm. So i have plenty left to do the firewall later on.

[robvanderveer]

Passenger side result http://img.tapatalk.com/d/14/05/23/a5ageje6.jpg

[ILM1010]

Does the DMCH carpet come with the foam attached to the bottom of the carpet pieces?

[DrJeff]

Does the DMCH carpet come with the foam attached to the bottom of the carpet pieces?

IIRC foam was attached in a few places... rear wheel arches, sides of the center channel... can't remember any others.

[vwdmc16]

As Jon has said, you will need to remove the mat on the top surface where the seat rails bolt too or they will jam and not really move.

[robvanderveer]

good point. but under the rails bit i used only 2mm thick isolation, and the problem of catching is not so much the isolation bit, it's the carpet that got freshened by the cleaning job. once that's settled the rails slide pretty smooth.