BWebb, I followed Jim Mayzurk's directions for filling the cavities behind the plastic wheel well liner on the forward side of the rear wheels. I sprayed "Great Stuff" (from Home Depot) expanding foam insulation into the crevices, then used larger hunks of foam to fill the remainder. One can for the smaller space behind the passenger side, two cans for the driver's side (just as Jim said). I could not easily find closed-cell foam so I used the other, but I will go back to replace later. The spray foam is sticky and can change shape as it expands, so follow the directions for gloves and eye protection.

This step made a very noticeable improvement in road/tire noise. I have not worked on the area surrounding the large speaker that is aimed at the back of the driver/passenger heads. I will look at that today.

I have not done much sound-proofing with the rear quarter panels (interior). But, for cosmetic reasons, I followed Doc Mirror's advice and stuffed vinyl-covered foam strips into the gap that can form between the window and the shrunken quarter panel. As Doc said, it isn't a high-brow solution, but it looks MUCH better than the gap and is cheap/easy/fun to do. I just stapled black vinyl around foam strips and jammed the stapled side into the gap.

 

I've done the entire 79 in Brown Bread and it made a noticeable difference. Now if you've ever seen a 79 vs an S4 or newer with the interior taken out, there is a biggggg difference. Much more sound insulation in the newer cars and I imagine just a S#$tload more in a GTS.

I went and Brown Breaded the whole rear deck (left a hole over the gastank level sender) did the spare tire cover, both rear quarter areas, floorboards from the back seat all the way to the front of the car, and again, this made a big difference.

I still have to do the foam in the rear fender wells like Jim M. and fill in the rear quarters (dead space with foam near seatbelt retractors, etc.) I'm puting rear speakers in the quarters (79's did not have these) similar to the 89 and newer cars so I need to dremel out recessed areas in the body for the magnets/drivers. I'll fill this area with foam before I install.

Also left to do is the doors. Now I have newer door panels covered with the same color as my original interior but panels are off an 83, so again, I need to dremel out a recess for the mid range driver as my 79 only had 4x6s. I will cover the entire face of the door with the brown bread. According to Jim Mayzurk, this is where you will see the biggest payoff. The area where I dremel out, I will concave with the brown bread and form an indention, making sure it will not come in contact with the window sliding up and down. If I ever need to get into the guts of the door, I'll just cut through it with an exacto and press a new piece on. I'm telling you, this stuff is very easy to work with.

Hopefully the 79 will be as quiet as a Caddy when I'm done. Just in time for one of DRs Old Bugger exhausts!!!!!!

 

Can someone take a pic of the Brown bread and B-quiet please? I will take a pic of my Raamat that I bought. I think its thin.

 

Thank you all again for the excellent information.
I will take a picture of my roll of B-quiet Ultimate for reference.

Can anyone post the link to Jim's write up. I seem to remember a few pictures but I can't find it anymore.

Paul

 

Thanks Paul.

 

Champagne, et all,

I did my 89 GT with the old style Dynamat (the brown stuff, not Dynamat Extream, which I think is better) over a period of several weeks while I was replacing the carpet. I only did one area at a time and was driving the car on a daily basis to and from work. I did every square inch of the car under every piece of carpet that was up against metal. The floor areas under the seats (front and rear) the hatch area, the bottom of the spare tire well, the sidewalls of the rear quarters, the tunnel area and the forward firewall on the driver's side. As stated by Chuck the biggest difference was when I did the doors. VERY noticable! The second area that was very noticable was the rear fender well area. The "B" pillar (forward of the rear wheel) is hollow and completly empty, just like an echo chamber. I filled this area with foam and the expanding foam from Home Depot. Again a HUGE difference.

Due to circumstances beyond my control ( I totaled the GT ) I upgraded to the GTS. This time I only did the doors and the "B" pillers and I think the GTS is just as quite as the GT was. I upgraded the stereo in the GTS and added Dynamat Extream to the woofer area in the rear quaters, but I can't tell a difference. Went to 6.5" woofers so of course I get better bass. Maybe the Dynamat helped the bass, but who knows?????

My write up was on the old Rennlist and there were no pictures.

Jim Mayzurk
93 GTS 5-Spd

 

Thanks Jim,

hope to see you at the 3rd coast. We'll compare notes

Paul

 

Maybe a bit late, but there is some interesting info here...
http://www.legacygt.com/forums/showthread.php?t=7036
on sound proofing.
jp 83 Euro S AT 49k

 

fwiw, I did mine w/the dynamat too... made a HUGE diff in sound levels, and made the stereo seem crisper cleaner too.... did the whole door and rear panels, along w/new carpet and seals... a nice inexpensive upgrade that really changes the character of the car, IMO.... I did have to put bulges in my front speaker areas to give the new speakers enough headroom though.... worked out well, wasn't a huge thing to do w/some foam and recovering work.... "ll be putting some new pics up later today on my sharksite, might help show what was done...

 

I am also going through the process now.

Brendon: I am also using raamat. It is a great product. I know rick personaly, and a lot of work has gone into his mat. It is speced relatively thin, but there is a reason for that. The constrained layers (vinly/aluminum/vinly/aluminum...) when you mat over mat, significantly improves the deadning capabilities. It is thin, so you can get more layers on in the same space. Its also a heck of a lot cheaper.

Rick (raamat) also sells ensolite at a good price. It is one of my favorite products. I put at least 2 layers of mat down everywhere, then go over it with the ensolite. It works great as a buzz killer between pannels too. I will post pics of my raamated s4 after the weekend.

Hans

 

As per Jim's advice I did the rear wheel wells and B cavity with FatMat (a B quite clone and a bit cheaper). I noticed a significant difference with less noise from the rear.
Will do the doors next.
Any improvement I had has been overcome by the muted roar of the X pipe at WOT.

 

Source for the muffling stuff (b-quiet or dynamat)? Is it very expensive?

 

H - Rick at raamat:

rick@raamaudio.com

Rick is a fan of 928s but thinks they were very loud at the track he visited.

Email him and ask for the "good stuff" 100 bucks a roll.

 

Thanks Brendan

 

Any pics from recent soundproofing efforts? Would like to see what folks have done. Hans?