I just finished putting Damplifier Pro in my 88GT. This is a CLD(Constrained Layer Damper) product. Its purpose is to dampen vibration in sheet metal panels that have a tendancy to amplify road noise and engine noise in the cabin of the vehicle. What it does not do is block sound. This is a huge marketing gimmick with this type of material. What it does do is lower the resonating frequency of the panels, which gives the sensation of quieting the interior. That's why the knocking test is so convincing... all it is showing is that the higher frequency sounds have been reduced. Also complexly bent and or welded metal like the seat mounts and the top of the tank tunnel, etc can't really resonate by the simple fact of their shape. So it is not worth covering them.

The majority of application examples of these products show users covering the entire interior of the car and using multiple layers. In reality only about 25% coverage is needed to properly dampen panels. Now I went significantly above this figure but I was aiming to use up what I bought... but I didn't over buy to cover everything.

What truely blocks sound are the products with a foam layer with a heavy vinyl layer. These products will block sounds but still only to a point. Lower pitched frequencies will still get through. Now with those products you want as much coverage as possible with holes only where they are neccessary to keep sound from leaking though. That will be stage two of the process when I can afford it.

Also, stay away from any product made with rubberized asphalt for an adhesive layer. These products will out gas when hot and continually harden until they start to crack and granulate, then you will end up with a floor pan full of sand and aluminum foil. This can then absorb and trap moisture which can lead to more corrosion. Look for products that use butyl rubber for the adhesive layer. Products made for automotive applications have a thicker foil and the rubber will not fail with time. DO NOT put roofing material in your car.

Here is what my car looked like after all the interior was removed exposing the floor pan and rear firewall.



Damplifier Pro comes in sheets cut into 12x20 inch squares. This is about perfect width for the Fiero's split floors. Here are the first two sheets installed...


The third and fourth sheets:

The fouth sheet was too long for the space it was in and the part that was cut off was used to fill in the gap left after the third. For complex corners you want to cut the sheet as its being layed down so that the piece can be laid smoothly. The sheets are fairly rigid as the aluminum is rather thick the cut lines in the corners allow the sheet to make a more simple bend and overlap itself.

The fifth sheet was placed in a rather diffucult spot. The floor here is rather complex with both a high level, middle level and a low level. I started with the sheet laid on the high flat and then pressed the simple bends to the middle level. Then I cut the lines that would allow for the sheet to bend into the lower level. The gaps that were created were filled with small pieces from left overs...


After the fifth piece it got complicated... the footwell is a PITA. I ended up cutting all sorts of pieces to try to cover the majority of it. Just so we are clear this kind of coverage is not neccessary but there is something theraputic about it so I kept going.



So a total of about 6-7 pieces were used to cover the floor pan and firewalls...

Now you can see that the gas tank tunnel is still bare above... this took about 3.5 sheets per side to cover using the 20in wide and cutting the bottom of to meet the material on the floor pan.

All the seams of the material were sealed using aluminum tape to prevent curious butyl from sneaking out. It also cleaned up the look of the installation.

I did not get a picuture of it but I stuck 3x5 rectangles inside the B-pillar lower vent on the out side surface and on the metal below the stricker bolt. These two locations resonated quite a bit when tapped. I also placed 4x6 rectanges between the screw holes for the clothes hooks and the third brake light for the same reason.

Here is a picture after I replaced the amp bracket... last thing before the carpet.


On the drivers side its pretty much the same thing with the exception of the wires for the speaker and seat belt sensor, and in my case the power lumbar connector. The wires are held to the floor using a simple metal tab that can be bent to allow the wires to be lifted enough to clear the sheet being applied. Remember to cut out spaces for things like the stand offs for the rear firewall panel and the bolts in the floor. The last thing you want to do is make life difficult later because you covered every thing in butyl rubber.




I did go right over the factory gum though... same spot on both sides the guy who worked on the passenger side was more generous than the driver side...


This is what I had left over after using the 36.5 square foot 'bulk' pack of Damplifer Pro from SecondSkinAudio.com... two full sheets and at least 1.5 more of pieces and parts that can be used to fill in holes to make the installation look nice. I have not done the doors yet and I will use whats left on them as well as probably purchasing a little more.


1600th post

[This message has been edited by carbon (edited 06-01-2009).]

It looks real good Nick. Did it make much improvement when you did the Dells run?

Actually yes... I was rather skeptical but with the windows up and just the sunroof tilted we could actually talk to each other in the car. Most road noise and a lot of engine droning was reduced... not completely gone but it helped a great deal. This stuff doesn't work miracles and there is still the fact that there is a nice window right above the decklid behind your head but apparently there is a reason they sell this stuff

My perception may be weighted by the fact that I was riding around in the car with absolutely no interior with just seats for a while before I started the project. I do think that it was worth the 165 dollars that I paid for it and I would never ever do it for someone else... It really is a pain in the arse at some points and I was just ready to be done when it was finished. If it made no difference at all I would be pissed.

really nice job but, like you said, that stuff is just a good starting point. An added benefit is that it pretty much "rust-proofs" your interior. Any leaks or liquids will just lay on the foil.

Yeah... I tried to go out of my way to make that point so that people didn't get the wrong idea about this stuff. There is a huge amount of money thrown away on these products every year due to incorrect usage and/or false information.

quote Originally posted by carbon: Actually yes... I was rather skeptical but with the windows up and just the sunroof tilted we could actually talk to each other in the car. Most road noise and a lot of engine droning was reduced... not completely gone but it helped a great deal. This stuff doesn't work miracles and there is still the fact that there is a nice window right above the decklid behind your head but apparently there is a reason they sell this stuff

The B-pillars are big hollow sections that really like to resonate. Did you put some dampener on them? I also shot expanding foam into the hollow roof sections through the coat hook holes. That helps too.

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World of Wheels Winners
My 3.4L S/C 87 GT
& My SD4 Indy

quote Originally posted by fierosound: The B-pillars are big hollow sections that really like to resonate. Did you put some dampener on them? I also shot expanding foam into the hollow roof sections through the coat hook holes. That helps too.

I did put some on pieces on the inside (through the lower pressure vent hole) of the B-pillars where they were really hollow sound towards the bottom, but they are pretty dead up top. I just applied some mat to the rear bottom of the roof section, between the screw hole and third brake light... I didn't mess around with expanding foam. I hit all the places that sound tinny when tapped. Like I said above... complexly folded and/or welded steel doesn't resonate significantly enough to warrant additional damping... the top of the B-pillar is one of those areas, at least in my car, and most of the roof is sandwiched and spot welded as well.

Thanks for the input!

[This message has been edited by carbon (edited 06-02-2009).]

The biggest difference I noticed when I did my interior like that was the seat backs didn't get anywhere near as warm as they used to. It made a huge difference in the summer. I still have the stock insulation on the engine side of the firewall. I added the aluminum layered mat on the interior also.

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'87 2.8v6 5spd
Fiero

Great write-up Nick... nice to be able to see the photos that go along with the info!

quote Originally posted by carbon: ...and I would never ever do it for someone else... It really is a pain in the arse at some points...

So you don't want me to drop my car off for this service?

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Looking for Fiero posters?

quote Originally posted by MinnGreenGT: Great write-up Nick... nice to be able to see the photos that go along with the info! So you don't want me to drop my car off for this service?

Dude... apparently I am so slow doing this... I didn't think it was so bad, but KEV spent a lot of time complaining about it from the chair he was sitting in...

[This message has been edited by carbon (edited 06-02-2009).]

quote Originally posted by carbon: Dude... apparently I am so slow doing this... I didn't think it was so bad, but KEV spent a lot of time complaining about it from the chair he was sitting in...

LOL! some how I could see that
so when is stage 2, 3 ?
D.

One word... money... I would like to say not long but we will see. We are going to Florida in two weeks to visit my mother so, yeah, money.

quote Originally posted by carbon: One word... money... I would like to say not long but we will see. We are going to Florida in two weeks to visit my mother so, yeah, money.

are you driving down? if you are stop by and say hi. I live just north of Atlanta.
the Dells was a long drive for us

I understand the money thing that is why my car is not done yet as well. but I am going to try to have it up there next year.
D.

No, we are flying. My parents always drive back and forth so that they don't have to have a car in both places. They offered a free high rise condo room and to pay for half the airfare... so we said ok.

I am a manage a very large hardware store the best cheapest product to use is DUCT WRAP used for same thing soundproofing cars or soundproofing pipes with a vacuum that make noise or insulation for heat. costa about $10-15 a metre about 1500 wide so for $50 u would have enough to do everything you could think.

List what the product is actually comprised of and then we'll talk. Foil backed foam or foil backed rubberized asphalt are not products that should be used in automotive sound damping applications.

[This message has been edited by carbon (edited 06-04-2009).]

A "search" bump

quote Originally posted by Australian: I am a manage a very large hardware store the best cheapest product to use is DUCT WRAP used for same thing soundproofing cars or soundproofing pipes with a vacuum that make noise or insulation for heat. costa about $10-15 a metre about 1500 wide so for $50 u would have enough to do everything you could think.

I would like this info myself!

Edit for iPhone retardness

[This message has been edited by GADJet (edited 09-16-2010).]

looks familiar!

I purchased my stuff off ebay. I agree w/ you that not every sq inch needs to be covered, I did so anyway because I had enough... One suggestion I would say to others is mark your bolt holes with a sharpie as your laying down the stuff (mark ANY location that needs to have something inserted into it). It makes it 100 times easier to locate them. Also, do not peal off the backing all at once! Peal off about 2 to 4 inches at a time and remove more as you go. Once this stuff makes contact, its a PITA to peal off... Also, try to do it on a warm day as it will be easier to form...

[This message has been edited by ALJR (edited 09-16-2010).]

I used the same material (Damplifier Pro in black) on my 88 Mera interior and it works fairly well. The worst job was doing the trunk (keep heat from the 3800 SC down) and that took 19.5 square feet of Damplifier Pro. Here are a few pictures of the installation. It does help with car interior sound levels and I have not yet done the doors.

Nelson

[This message has been edited by hnthomps (edited 09-17-2010).]

It seems to install well or you just did a good job but how thick was it?1-2mm-6mm? how thick over all description seems to state insulation is less than the hardfoil i would think it could be thicker is 2mm insulating? Can you get this stuff thicker? Or are they trying to sell more products rather than an all in one.

[This message has been edited by Australian (edited 09-17-2010).]

Duno how thick the OP's stuff is... The Ebay FatMat I used is about 1.5mm... It is NOT going to reduce the cabin noise! It just changes the ping'y sound to more of a thump'y sound... You would need insulation to reduce cabin sound; like wool carpet liner works good...

quote Originally posted by carbon: I have not done the doors yet and I will use whats left on them as well as probably purchasing a little more.

Nick, I did mine years ago with Dynamat's version, then Dynamat's layer of foam with a layer of lead like metal in the middle on the floor for more sound deadening. It works awesome. However my biggest surprise was the doors. I used a single large piece of the rubber/foil stuff to cover the entire door under the door panels, then filled in the rest with scraps. WOW. The road noise inside the car dropped dramatically. I could talk over the 3800 with no muffler.

I made sure to completely cover all the holes, and another neat trick is where the rods for the locks and door handle come through, just stick a small scrap on the back, sticky side to sticky side, where the rods slide. The aluminum provides a "non-stick" way to let the rod move and still really seal it up. The down side to any of this is when I need to remove some of it to work in the door, as you know, it doesn't come off... But, you can just cut it open, replace a power window motor or whatever, and put a patch of it back over the hole.

Looks Great!

quote Originally posted by carbon: but KEV spent a lot of time complaining about it from the chair he was sitting in...

LOL!!!! NO way! Kev??
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Intercooled SC3800 II/III mated to a Getrag. 19's with 13" Brakes on all 4 corners. 5 years Avionics & 15 years Car Electronics.

[This message has been edited by MOBILE (edited 09-17-2010).]

very nice! to bad the owner of second skin is a chode :/ nice product though! you did a great job.

I sprayed my entire interior with Lizardskin Ceramic Insulation and I also did the engine compartment after removing the dirty fiberglass insulation. Hopefully it works well. Unfortunately, I won't know for quite some time until I get the car put back together.