Chuck Schreiber

Several years ago I took the time to lay down a pretty good amount of sound deadening material in the 79 and was pretty impressed with the significant sound reduction in the car. I ended up doing all the panels from the front to the rear (floorboards, rear quarter panels, B pillars, rear deck, etc.) The only place I did not do (or haven't done yet) was the doors. Still have to cut holes for the upgraded speakers, etc. but have not gotten around to it.
Bottom line, even with the doors undone, the car was significantly quieter and felt alot tighter (no rattles, whatsover) over bumps etc.

So, after spending around 700 miles (to and from plus the fun run) in the GTS the other week at the 3rd Coast event, I got to thinking that the 79 still sounded quieter. Even with the heavy GTS rear deck mat, thick rubber cusions under all the carpet, etc, and overall just loads more sound deadening than the 79 had, I figured what the hell, I'll start on her and see if It will make a difference.

This time I decided to START with the doors, then move to the rest of the car. The Thing that I did not like when I originally put the deadener in the 79, was the gooey mess that the seams left. Sterling had done the same thing to his car before the Paul Champagne interior was installed and said he laid down silver tape to cover up the goo between the seams to make the install nice and clean. I took his advice on it and it did make a nice clean install that would not leave goopy tar residue all over the back side of the panels.

I have to say I'm pretty happy with the results. When you slam the doors, they do not sound "hollow" anymore, but close with a "thud". (Even with the door panels off!!) I've only driven the car with one of the doors done, but will take it out again once I get the other panel back on and post another report on it. Just the one door made a little difference, I'm sure the second will be even better.

I took alot of time to make sure I left any and all bolt holes, door fastener holes, wiring harnesses, etc. uncovered so if I even needed access to them, I've got a clean shot at them. If I actually need to get into the door, all I've got to do is cut with a box cutter through the material and trim away. The stuff is sticky enough that you could just pop another piece over the hole (just slightly bigger) and press into place. I also installed right over the moister barrier. So if I needed to remove the barrier, the bbread will come off over it. The moister barrier on the GTS had good solid contact with the door panels.

After the doors, I'll do the 4 floorboard areas, then the rear deck. The GTS has a ****load of foam over the rear quarters and wheel wells, but I'll foam the hollow B-pillars like Jim Mayzurk did. He said he got great results doing this.

I used Brown Bread from www.B-quiet.com This is a discontinued product that looks like it was replaced by B Quiet Extreme. Still looks like the same stuff. The tape I got from Pep-Boys and its labled as Nashua Tape on the inside of the roll. It looks basically like chrome tape with the consistancy of aluminum foil that sticks really well.

I used a pair of good fiscar scissors to cut the pieces of BBread, but they get gummed up pretty quickly. Sounds like a good pair of tin snips would work better. I've posted some before during and afters below.

If anyone has been there, done that, and has some good tips I'd love to hear them as I still have the lion's share of the car to go. I'll report back more as I make progress. I've posted some before during and afters below.

Ducman82

im doing the same thing, but i started on the floors first.




im using a product called FATMAT. nice and thick, and cheaper then Dynamat. i still hope i can get replacement foam for under the seats and for the tunnel. part numbers still look good. did you do the doors on your 79 like that?

Jim M.

Chuck, just a couple of pointers: Go to a good hardware or tool store and buy a "J-Roller" it's used to lay down formica or wood vineers. You use it to completly press down the sound deadener onto all of the depressions and curves of the metal panels. I also used a small wooden roller for the really tight curves. Also when I did mine I went to the edge of the wiring harnesses on the top edge of the doors, and even rolled it down past the lower edge of the door panel. (You can only see it if you get down on the ground.) When I did mine the entire door was one piece of dynamat so I didn't have any seams to cover with tape. It took more time to fit and cut before I peeled back the paper to expose the adhesive but it was a cleaner installation.

When I did the 89GT I was doing a small section at a time and driving the car every day between jobs. I never could tell the difference until I did the doors. So on my GTS the doors and B-pillers was all I did. Still made a big difference.

Nicole

Could the sound deadening material also be installed on the inside of the door panels, rather than on the sheet metal where it blocks access to the door's mechanics?

Ducman82

thats what i plan on doing. take more work, but works just as well.

S4ordie

I second putting the deadener on the inside of the door panel. The closer you get to the outside the less noise and vibration will get through.

I will be doing sound deadener on my car before the Paul Champagne interior is reinstalled. I've done a lot of research the past couple of months regarding the many options for sound deadening. There is a lot of over lap in claims and results. I came across this guy in Maryland who is a NVHT engineer (Noise Vibration Harshness Test) who is really schooled in this sort of stuff. He has some products, especially his CLD Tiles that I intend to put on the inside of my door panels and on the inner roof panel.

Here is a link to his website. Just click on the pic that says CLD Tiles to get more info. This is a new business but I like his background and have communicated diretly with him. For you folks in NoVA and MD he would be a great local resource.

http://www.sounddeadenershowdown.com/cgi-bin/index.cgi

For those of you interested in a spray on/in option as well I found this stuff to be well considered and recommended. I believe Paul Champagne pointed me towards this product

http://www.secondskinaudio.com/sound...ctrum.php#tab4

I love the idea of high performance in my cars, just not high volume, at least on the inside.

Chuck Schreiber

Dan,
Good stuff! Looks like you've been doing some serious homework, but I'd expect no less than that from the naked cowboy!!

Nicole, yes. You can put it on the inside of the outer door panel as well. I'm starting with the inner door skins, then to the rest of the car with what I've got.
I'll probabably work my way to some of the products that dan pointed out in the above links. Looks like you need to do "Combinations" of differenct products to quiet the car down, so I've got a ways to go from just my 1 layer of BBREAD.

Also, looks like in addition, you can coat the inside of some of the panels which will probably help as well. I searched and came up with this:
http://members.***.net/my_1987s4_928...tallation.html

He used Quiet Coat Spray on the back of his door panels during the his stereo install from these guys http://www.cascadeaudio.com/

More specific info from them here http://www.cascadeaudio.com/car_nois...r_barriers.htm

Lots of info out there, just need to dig through it all.

Chuck Schreiber

Ok,
Just had a chance to take the car out tonight and I'm pretty happy with the results!

I had a nagging rattle in the driver side door, it's now gone. Hopefully it will stay that way. Just doing the doors made a pretty good difference driving around town. Seemed more solid, but could be my hopes of it turning out that way!

The rattles may have been all the friggin loose change that fell out of the door when I removed the door panel. I had about a $1 worth of pennies, nickles, and dimes fall out of the bottom of the door onto the garage floor when I popped the last few retaining spikes off the door skin. That could have been some of the rattle??

Bottom line, I'm pretty happy with the solid feeling of slamming the doors without rattles, and the noticed reduction in noise from that area while cruising. Not like I'm driving a 2009 quiet Caddy, but I'm getting closer!

Guess it'll even out when I put the X-pipe on!

Aspkiller

I've sprayed Lizard Skin on metal parts, both inside and on the firewall and tranny tunnel, mostly for the temperature benefits needed in stripped down race cars. In areas where fluids like oil, brake and fuel might come in contact, I applied a truck bed liner over it for further protection. Then I used light weight sound mats. Dramatic temp difference and very good sound diffrence. But looking at what you're doing on a full interior daily driver, it seems like you already have a great system. Thanks for the info. I'm sure to use some of it on the next (if there is a next) build.

Tom in Austin

Hi Chuck, I've done almost exactly the same project, started with the doors using a similar material on the inside. It makes a nice improvement like you said when the doors close with a solid 'thump'.

Have about a half a roll of the stuff left, sounds like the B pillar area is best place to go next? Thought about trying the rear wheelwells (on the outside that is) ... when that's done and new fender liners become available to cover it over could be a nice combination to cut down on rear tire noise.

Tony

I took a bunch of plastic bags and stuffed them full of "pillow" stuffing or the likes. Then with a stick weged them up in the B pillars behind the door. Its just a large hollow cavity up there, it made quite the difference actaully. I have a Radio Shack Db meter i measured it all with. But unfortunatly i cant find the paper i had with the before and afters on it. I did my doors with the Dynamat stuff also. There was a measureable diffrence.

Tom in Austin

Hey Tony, how did you access the B pillar area to do that? Is there a convenient opening somewhere?

Tony

take the rear wheels off and remove Fwd inner fender liner. The with a flash light you can look right up to the top in side. Just a big hollow area. I think the GTS's actaully has some deading material in there, but way up at the top, not in the entire cavity?

Chuck Z

Good stuff here guys!

I will watch this with interest and do my GTS when the dust settles from Kermit and the suspension mods I'll be doing over the next couple months.

Korwen

This is something that I've considered as well, however I've got a question that hasn't been asked.

I've seen where people take out all of the sound deadening material for weight savings on track cars. Given that it's 20+ year old technology in my car, I'm wondering if it would not only be more effective, but also lighter, to remove all of the factory sound deadening material, and then replacing it all with new (hoepfully lighter?) materials such as dynamat. Has anyone done this, and would the weight savings be significant, and the sound deadening more effective?