Sound deadening project...

[mazdamx3freak]

So my MX3 is pretty much gutted and tire well is cut out for my 350z exaust system . Im trying to reduce the road noise/ exaust note considering most for my interior is gone. So I have some ideas.... I already started to wrap the hatch/rear area with roof flashing. Which I am already really supprised with alot of rattle/squeaks are gone. But as for the "dead space" between the body and quarter panels what should I fill it with? I was thinking a mixture of home fiberglass insulation and polyfill which on paper it looks like it would work but will it? I will post pics of my project and write a review on how it works out. Any help input would be great!!! thanks guys!

Here is what it looked like when I started the project:

[MazdaNoob]

use expanding foam if anything ... but just remember anything you add for sound deadening will add weight ... considerable weight. if you are doing this for sound quality for stereo then you will want some asphalt based deadener for the floors and any panel you can get in contact with. use cheap stuff for the floors but use a really good quality for vertical panels or the heat in the summer will cause them to peel off

[mx-3_4evr]

Just leave it how it is! Why would you add more weight?

[mazdamx3freak]

Just leave it how it is! Why would you add more weight?

well I do uderstand your point on weight b/c I pretty much elimnated everything except for motor,tranny, harness, interior harness. and I have my mx3 down to about 2250lbs (just subtracting weight I pulled off, which I took so much off its prob. less lol!) But as a DD also exaust and road noise is a prob. all in all I plan to put about 20lbs back on sound deadening. which right now its worth it imo. So im just tryin to find the lightest/cheapest alt. to reducing a lil noise from outside b/c my car was Stripped! I mean litterly I could see outside the car between body panels LOL!!!! And a MAIN thing is to seal all the passages so no dust/dirt/ exaust fumes get in the caben like they have been I think thats the main thing!

[MazdaNoob]

then weld all the seams

[Rice'sRocket]

wow, looks like my back of my protege. What I have been planning to use on my car is a chemical that comes in a can that expands called GREATSTUFF. expands like foam and is very lite weight. I then plan to use DYNOMAT to cover. A sheet of dynomat is $30. The can of greatstuff is a few $'s. I expect my cost to be around $200 and have will have added around 40lbs to the original 60lbs taken off for a total of 20lbs lighter.

[5l1mm]

wow.
ok so i stared at this thread for a bit.
the i came back and actually read it.

id like that start by saying
"screw the haters"
road noise is freaking annoying.
ther is actually a such thing as quality of life.
road noise is not part of quality of life if your car gets mad miles.
my car, for one gets mad miles (like 250 a day or so, 90 on a slow day)

im in the mission to sound deaden as well.
i noticed that dynomat extreme is zinc foil on top of a sheet of dumbdumb.
i tried laying seams of dumbdumb along the interior panels of my car, and covered them with masking tape to keep the nasty level down, and it seems like a few strips isnt enough for noticeable deadening.
although i would still recommend it in seems, or urethane.
ford i think uses a urethane style adhesive in strips down the car to deaden road noise.


if you use great stuff, or any expanding foam please allow proper venting of expansion. its not gonna work unless it fluffs up all the way.
pluss ive heard horror stories of it expanding and blowing seams in body kits etc.

/$0.02


ps, im ****ed up so dont hold my grammar errors against me

[mazdamx3freak]

yeah thanks for the advice guy! Im pretty sure I wont use great stuff consider im a electrictrican and I have to use that stuff all the time and I hate it!!!!! It does fill holes nice but that crap is too damn messy to be putting in my car. I literly have a pair of pants that are forever covered in that stuff and will never come out.

[5l1mm]

yeah thanks for the advice guy! Im pretty sure I wont use great stuff consider im a electrictrican and I have to use that stuff all the time and I hate it!!!!! It does fill holes nice but that crap is too damn messy to be putting in my car. I literly have a pair of pants that are forever covered in that stuff and will never come out.

i concidered it, and i still do
heres the fantasy.

get those 10 mil contractor cleanup bags from home depot.
tuck the bag into the panel, and all the little nooks, and crannys.
fill bag with expandy foam.
scrunch top of bag around a tube, tape shut onto tube.
stick tube into a bucket that you dont mind getting ****ed up with foam.

i havnt tried it yet, but it seems possible

[Rice'sRocket]

well....I am pretty sure that with no back seat or panels it will have plenty of ventalation. I do not plan to use behind body kits for that very reason. I had a buddy replace his metal bumper with Greatstuff and that turned out badly when he hit a tree forgetting to pull his ebrake on his 240sx (formally my 240sx). So I dont think I'll be using it for reinforcement lmao. Defenitly a good material since it can be shaven to any contour that is required and good for heat insulation for winter. I plan to use that and then put fiberglass on top in a few layers after I put the rollcage in.

p.s. - always use old beatin clothes instead of good ones for when you work on a car lol.

[FE3-323]

Dynomat is overrated junk google "E-dead"

[FE3-323]

http://www.edesignaudio.com/index.php?cPath=1_24

[Rice'sRocket]

Nice find. I will def be using as a first layer

[Kitty]

dry ice the crappy stock sound deadner/insulation off, it is useless. Get the damn thing rino lyned.

/thread.

[5l1mm]

dry ice the crappy stock sound deadner/insulation off, it is useless. Get the damn thing rino lyned.

/thread.

hush peanut gallery!