Go to an auto upholstery place, ask to buy some of their carpet padding. It's the right material. Foam stuff can collapse and lose its shape over time. Costs about $40. Lightweight. Doesn't soak up water. That is what I did.

Dave

I lined mine with 1/2 inch closed cell foam that I got bought from a small distributor here in town that had a zillion types available -- many in stock.

The stuff I used weighs about 1 oz per square foot. I wasn't concerned with noise, but I was with weight. I don't remember the cost, but I've got all the records. I'll be out of town until next Wednesday, but I can get you all of the details when I get back.

I didn't cut or grind any of the seat or panel mount tabs and bosses, I just built up the foam and covered them before adding the carpet on top. You've got to cut the foam into jigsaw-like sections and glue it in place. I used 3m super adhesive spray for both the foam and the carpet -- It's not going anywhere.

I did it in the summer, so cold wasn't a problem. The carpet was perlon, so it was pretty easy to strech once the glue was on it. A hammer and duct tape covered
section of 1x2 were used to encourage the carpet to conform to the tighter shapes. You can see them in one of the pics below.

I also made a backing for the package shelf out of corregated plastic sheet, and glued the carpet to it. The shelf is held in place by the original strap loops, and a strip of velcro on the back side of the flap that extends down to where the seat back used to be.

There are a few pics below. I don't have a good finished shot, but I'm in Denver so you're welcome to stop by and see it in person if you like. I've also got some leftover foam scraps so you can see it first hand.

Good luck.

Joe

http://forums.pelicanparts.com/uploa...1236839082.jpg

http://forums.pelicanparts.com/uploa...1236839487.jpg

http://forums.pelicanparts.com/uploa...1236839589.jpg

http://forums.pelicanparts.com/uploa...1236839964.jpg

http://forums.pelicanparts.com/uploa...1236841026.jpg

I know of at least two people that have suffered tinnitus from just driving their 'track-day' cars and I'm sure there are plenty of people out there that wouldn't be prepared to suffer high levels of noise at work but are more than happy to screw up their ears driving their car?

Anyway, to answer your question, I didn't do any scientific measurement but my son's ears 'claimed' the engine was quieter and I can now hold a sensible conversation in the car, however I have not removed the Porsche 'tar' from the front of the car (still in good condition) or treated the doors, roof or any other penetrations and of course I still need to complete the RS carpet installation which should help again.

Martin

A very nice solution :)

Thanks Martin

When you say "Porsche 'tar'" do you mean the tar like substance in sheets on the floor?

I've used that type of foam for making a sea kayak seat. Great stuff to work with. I'd think it would be good for keeping out noise. Beautiful job Joe. Thanks for more inspiration. If you do have any 'finished' pictures would love to see them.

Yes, it seem to be some sort of a poured flexible product applied at the factory rather than a sheet product - anyway mine was failing in the rear footweels so I chiselled it back to the metal floorpan which I then treated with Por15 before applying the Dynamat.

Martin

Joefrantz - that tub looks soooo nice, you should have just left it bare ;-).

Carpet looks fantastic too however.

Todd

Nice work Joe, that looks great. I am going to borrow your idea when I recarpet mine in the spring with RS Perlon.

BTW, I noticed the Kitchen Spatula in one of the back seats. :) I'm not sure how many times my wife caught me using a kitchen tool in the garage. LOL

watch-in

more generally -- DynaMat has a number of products these days.

any asphaltic or rubber-type sheet products will reduce panel resonance, simply b/c they make the panel heavier (lower resonant freq.) and whatever absorption takes place as the waveform travels thru the material

this type deals with low freq. sound

the lightest solution to high-freq. sound transmission that I know is currently available is micro-ceramic bead encapsulated product - Quiet-Coat (sp) makes these

they change the sound wave into heat -- it is all motion, right?

search for more info

Joe - I also like your foam solution and stole a pic from the post...

re foam, the diligent may want to check on:
- fire safety issues
- heat transmission (bound to be lower, but how much?)
- somebody is bound to have measured noise transmission (as a f(freq) ) for closed cell foams...


some links here:
http://forums.pelicanparts.com/porsche-911-technical-forum/462446-background-cabin-noise-reduction.html

This is a great thread. I was planning on buying this carpet kit for my project.

Joe, that looks perfect! And the pics are very helpful, thanks.

One question though - although I understand you built up the foam around the brackets and other things sticking out, did you also leave in the big seatback attachment hub on top of the center hump? If so, I'm surprised it doesn't show more through the carpet. I was planning on taking mine out, but maybe I don't have to.

Lots of great ideas have been proposed here.

Inexpensive asphalt based sound deadening material...
 

Bob at APPBIZ here

We have been using various roofing materials for sound deadening for years. Some are very similar to Dynamat at a small fraction of the cost. Go down to your local roofing supply and ask to see some "peel and stick" This is not a brand name it's more the slang term for this type of material. It is gererally sold by the roll but you can often get the counter guy to sell or give you cut lengths.

While running a sheet of Dynamat through our door panel moisture barrier die for a customer, I noticed an asphalt smell. I decided to take a piece to the local roofing supply and showed it to the counter guy. I told him what it cost and what it was used for. He started laughing and called a few of the guys in from the shop they also started to laugh. He then told me it was bascally "peel and stick" with a logo. They were blown away at the cost, I ended up leaving the place with a 70 pound roll for a few hundred dollars. Enough to do many many many cars, we still have some of that same roll left.

In addtion to the roofing material we like to use a poly based felt carpet padding to smooth out some of the bumps. It is kind of hard to find as it is only used in really really high end residential carpet installations. We have a good source and always have some on hand. If you guys need some or want a sample so you can find it locally give me a call or drop me a note.

Thank you all for your patronnage
Bob

Can someone maybe post a picture of the front kick panel area and explain how you did it? That is the last peice I have left to install. Quite Honestly, I couldnt find a way to make it look or fit right
Thanks in advance
Keith

Exactly. I discovered this when I ordered a small qty. of this same material from JC Whitney. Dynamat without the logo. The shiny mylar facing isn't necessary.

Sherwood

Exactly #2! There is an outside chance that it has some fiber or something in it, but I doubt that.

mylar will reflect the radiative heat component of the total heat transfer - go to REI, buy a space blanket (the tiny survivalist one) and stick that on there if you want to reduce radiative heat Xfer.

Bob - is it worth your while to investigate what Lotus or Porsche are currently using for carpet, underlayment, padding, or acoustical foam?

Dave,

re the seat hinge: I didn't remove it. I cut a series of "collars out of the foam, in graduated diameters, like a wedding cake (I don't remember if it was 2 or three layers). I then applied the layer of foam over the center hump and hinge. There was still a slight (1/8 " ?) high spot showing, so I took some 60 grit sandpaper on a sanding block and shaved the high spot down. If you look closely at the pictures
you can see the spot -- it's a white oval right over the hinge .

Noel -- That spatula lives in my tool box. It's an accessory from an old Cuisinart food processor. It's not like a typical soft rubber spatula. It's made of hard plasitc, and the edges are very sharp. It's one of my favorite tools.

kmhemi -- I've got some kick panel pics that I'll post the next time I get back to Denver next week. Essentially, I didn't want to deal with the sill and heat ducts in that area, so I made some more panels out of the corregated plastic that create a flat surface in the kick panel area.

Bob, it sounds like you are decribing something like * Grace Ice and Water Shield*. Do you remember if that is what you used? This stuff is about 1/8" thick, sticks like crazy, is self sealing, and is water resistant. I'm not sure how well it works for stopping sound transmission though?