blown 87

Neat stuff, thanks Circlex, good info.

Speedtoys

Stuffing foam down into the body cavity under the rear passenger speakers helped me out a lot.

The next cavity to fill is behind the door latch area..havent put much thought into that boomy area yet.

Andy Kay

Jeff-Where do I obtain such foam you speak of and what is it called? Love your avatar

Speedtoys

Ohh..it was from the upholstry shop I was at getting my rear 1/4 panels dyed, and replaced. Just blocks of closed cell foam used in car seats/etc.

blazing928

Second Skin Audio [SSA] product are what I used.
In the old "sound deadener showdown' web site SSA was what came out best, it was cheaper and stuck better than the others and any bitumen product can smell for awhile.
SSA now has a new deadener with the thickest allu top sheet, only good for flat surfaces.
I have read that to stop panel vibration then as previously posted you only need to do about 25%, however the alu top sheet DOES reduce noise.

It seems that each product works at reducing different frequencies.

I also paint over the deadener a coat or two of SSA "Sludge". its a matt white paint with little ceramic beads, they reduce heat and convert vibration to heat as well. Its a very effective way to reduce noise for less cost. My hatch also does not get hot inside anymore from the exhaust.

I have done the doors with a layer on the outer panel, both sides of the inner metal panel and under the cardboard door skin. This made the biggest difference vs floor and hatch. Yet to do rear seats and rear QTR.
As I am chasing sound quality, the doors are very important and have made amazing gains to the sound quality of the speakers. Sealing up the holes is also an benefit.
I wanted the top layer to really quiet the car but the freight for it was going to be $600 to OZ, so I am looking for a local top layer.

Painting the inner rear arches with bitumen type or rubber sound deadening, like 3M etc does reduce the tyre noise as well. I think that doing the rear 3/4 panel will be the next big win.

If you have the motor out there are some products like Kool Mat, that would be a great replacement on the fire wall.

m750rider

For the floor mats, I used new foam purchased from Bob Budd at Classic 9. The original foam on the carpets was still in pretty good shape but had acquired an unpleasant smell. It is attached pretty well to the mats,but I took it off, leaving just the fabric of the carpet and placed the carpets directly over the new foam. It lays flat, works fine, doesn't smell anymore. I also put it in the rear hatch area.

Chuck Schreiber

I used the Brown Bread (Now called B-Quiet Extreme). Used in both cars and made a big difference.
They have quite a bit of sound deadening products on their site:
http://www.b-quiet.com/

If you go to installs http://www.b-quiet.com/installs.html there are some good pics of it already in the car.

The Extreme on the metal panels of the car combined with the V-Comp padding (which looks similar to the padding we had on these cars from the factory) should do most of the trick.

For the B-Pillars, expanding foam will fill in the rest. You Dont need to use too much, as it dries, it expands like a loaf of bread in the oven.
http://greatstuff.dow.com/?utm_sourc...ign=GreatStuff

For a pretty cool idea on reducing noise on the interior panels, go to this rennlister's site and scroll towards the bottom. It will show the back side of the door panel and how he added sound deadener as well as a product called Quiet kote spray.
http://members.***.net/my_1987s4_928...tallation.html

Quiet Kote website. (or one place to buy it)
http://www.emspowered.com/storefront...roducts_id=224

From Quiet Kote:
Quiet Kote is a revolutionary, sprayable visco-elastic vibration damper for treated or coated metal, fiberglass, plastic and wood that represents the latest in sound deadening technology. Quiets vibration and rattles in vehicle body panels, doors, and plastic and fiberglass trim, or can be applied to the outside of a vehicle (fender wells, underbody, etc.) Also seals and dramatically improves the performance of loudspeaker and subwoofer enclosures. Waterproof, sprays like paint, and stays pliable...will not chip. Each 20 oz. can will cover 2 average size car doors, but one can per door is recommended for competition vehicles

Maleficio

This thread reminds me of what my home audio rack unit was doing under higher SPL's: it was ringing, and drove me berzerk.

So I bought a pack of adhesive-backed round rubber mats used to install under heavy items to prevent scoring on a table-top, etc. Sticking one rubber mat on the rack instantly cured it of all ringing.

It may not be necessary to buy that expensive sound-deadening goo.

Rubber feet:

http://www.radioshack.com/product/in...ductId=2103342

Podguy

I am re doing the engine well on my 78. The material on the fire well melted and shrunk. For this I used Lizard Skin. It sprayed on nicely. Over the sound material sprayed a coating of Lizard Skin ceramic. Easy to apply. Water clean up. They push the 2 gallon kit, but I found 1 gallon for half the price. It can be sanded and painted as well.

I am not sure how this will work but so far it is a great product. They recommend it for interiors as well. It is a lot easier to apply than Dyna Mat we used on Eric's car.

FLYVMO

Dan,

Check out this test of various materials. http://www.dctra.org/files/1974_TR6_...r_Showdown.pdf

If you're in a hot climate some of these sound dampers will melt (the asphalt content) and make a big mess. Only Secondskin Audio, Dynamat has pure butyl rubber, others use asphalt for adding weight. Raamat uses inert asphalt so will not have the same melting problem and is very cost effective. From my own research the best options would be Second Skin Audio, followed by Dynamat and then Raamat.

On top of that, you would then put closed foam "decouplers". This link has some decent products at very reasonable prices: http://shop3.mailordercentral.com/su...ts.asp?dept=17

Cheers!
Carl
90GT

Podguy

Carl,

Thanks for the feed back. I used Dynamat on Erik's firewall and it seems to be holding up well. I used Lizard Skin on my 78. It was easy to apply and the clean up is great. It took several coats, but they could be put on with an hour of drying time between. Only the ceramic coating required 24 hours whe putting on over the sound deading layer. The surface can be sanded, primed and painted. The material sands easily with 120 grit.

Of course the engine is not in the car yet do anything can happen. I will update my web page when the car has run a few thousand miles.

Thanks again for the reports. Do you know a good source on the closed cell foam?

xschop

Best bang for the buck and no mess is the EPDM sticky sheet you get from Lowes. Inexpensive, Lightweight and does the job.
Found the pics....the stuff is called "Tite Seal"
http://944hybrids.forumotion.com/t55...ight=nailed+it

Ducman82

i used Fat Mat (kind like dynamate but thicker) and replaced the stock under foam with Closed cell vinyl rubber matt.

FLYVMO

Dan,

Raamat has some closed cell foam but only in one thickness I think (1/8 inch). I plan on using different thicknesses in layers (1/2 --> 1/4 --> 1/8 inch) to get the approximate factory thickness in order for the carpet kit to fit and look like a factory installation. These folks http://shop3.mailordercentral.com/su...ts.asp?dept=17
offer a sample kit which I plan on ordering in the near future.

Cheers!
Carl

Podguy

Carl,

For the carpet I used the orignal carpet with the backing removed. it cleaned up nice and with a little carpet dye looked new. I then had a foam pad and vinyl sewed to the back. The foam gives the carpet some substance and the vinyl sealed things up. The nicest one was the rear carpet. Which can then be trimed so it folds rather than hanging out over the rear of the car. I am strong enough to lift out the spare without hitting the car.

I tried to make some under pads to replace the smelly and ugly foam by using some foam and gluing on some vinyl. It did not turn out very good. By combining the foam and locking it in with sewed on vinyl the carpet holds its shape and is much easier to deal with.