New carpet, soundproofing, and dynamat - any tips?

[TTait]

I had those screws on both side, just neglected to mention them.

I've been wondering about finding the holes, didn't know they would telegraph that well. I considered getting one of those dual head laser pointer things that you mount to the garage ceiling to park your car in the same spot every time. Figured I could "mark" the location of two screw holes at a time with it before the mat goes in and then cut them out based on the laser pointer.

[john 05141]

I added Dynamat in my delorean 3 years ago. The complete back side, cargo area, on the rear wall, and inside of the wooden back plate, the rear wheel wells, all over the bottom,..; But I can not say it is much quieter... honestly.... can not hear any difference!! This was an expensive add-on and was not worth the high cost and extra weight you're driving along with all the time.
But it did not interfear with my console or any other part. The only thing worth mentioning is that the rear wheel wells became thicker of course, and I needed to grind the opening on the wheel wells in that board to get some more space.
Perfect fit afterwards.

john

[dmc6960]

For REALLY good soundproofing, a lot more is needed than just Dynamat.

Dynamat is designed to reduce resonance of panels. In our cars, the floorboards under your feet, and the bottom of the shelf after the worst offenders. If nothing else, put Dynamat on these areas, directly to the fiberglass.

The next steps of soundproofing, now that the resonance is reduced, is to block and absorb the sound. Certain foams can be really good at absorbing sound. Unfortunately to get the really low tones, impractically thick foam is needed. So a 1/2 inch of good closed cell foam will do decent at absorbing the higher tones. Finally, blocking the sound is accomplished with loaded mass damper. This is a really dense piece of vinyl. 1lbs per square foot is good. Attaching it on top of the closed cell foam will decouple it from the panel its attached to, further blocking any leftover resonance from the panel. Optionally, a second layer of this (1/2" foam/loaded mass damper) would improve it even more.

Looking at the stock soundproofing, you can tell a similar practice was used, but with lower quality materials than available today. Plus the original stuff is all dried and cracking now.

For best results, Dynamat only needs to have about 50% coverage in the middle of a large panel (however I myself have 100% coverage as well). Then the foam and mass damper need to be formed exactly over all areas and sealed to the surface (contact cement or strong spray adhesive).

I'm even considering removing the stock foam on the back of the carpet, then using a new high density foam and mass damper under the carpets.

[TTait]

Took a break today, back on it tomorrow - 90% of Dynamat in, and the SpecialT/KenK soundproofing kit is ready to go in. I need a little help here too.

Many of the pieces in the foam kit from Ken are self explanatory, but a few are leaving me puzzled.

Looking at the large piece that goes behind the rear vertical trimboard. I have not yet removed the foam from the trimboard, and was about to. What I notice is that the new insulating pad comes out far enough to overlap with where the foam on the rear trimboard is, but not the full width of the trim board. I would like to remove all the trimboard foam and just use your neoprene, but was it intended that I just trim back the foam and leave it in place at the outer extremes of the board?

For the center of the parcel shelf, I’m assuming that the closed cell foam goes down first, and then the heavy rubber over it.

Pontoon Wall left and right are like the parts diagram. The rubber pads for under the electrics panels are self explanatory.

Now look at the attached pic.

I believe two of the remaining 4 pieces are for the pontoon roof, but but the design appears different from the stock design, and I’m trying to get this right. I’ve attached a photo with A-D designations on the four remaining pieces – I’m guessing two of them are pontoon roof, and the other two?

Finally, I’m planning on using the pictured spray adhesive to put these parts in. If anyone needs to suggest a different product let me know?

Thanks for any help.

Tom

[TTait]

Making progress - still not sure where to install A above.

Properly fitting the carpet piece with cutouts for the battery and storage area right behind the seats is proving challenging - any advice on where to start first would help.

Tom

[outatym2001]

Here are my pictures of what I have finally completed. The pictures show a combination of Dynamat Extreme and eDead 120 from Elemental Designs Corporation.

Sound Deadening - for interior to be attached to Glass Reinforced Plastic (GRP) body
eDead 120 is 115-120 mils thick and has self adhesive on one side and aluminum foil on the other with Bytul Rubber in between. It is sold by the square foot so you can buy as little or as much as you need. One square foot weighs approximately 16oz or one pound.
http://www.edesignaudio.com/

Products like eDead 120 are much cheaper than Dynamat and as good or better.
More products below.

Vibration Dampers, Noise Barriers, Rattles & Squeaks
http://www.secondskinaudio.com/

Other noise insulating manufacturers.
http://www.soundcoat.com/
http://www.emtechinc.net/insulation.htm

One thing I noticed since adding the over priced Dynamat Extreme and eDead 120 is that engine noise and noise from the rear tires is reduced but not completely eliminated. This stuff is NOT sound proofing it’s better described as sound reducing.
I can now hear gear whine when accelerating and decelerating from my five speed manual trans. and I can hear wind noise and front tire noise. So I conclude that reducing one noise brings out the others that I wasn’t aware of until now.
The only thing I can think of to reduce all the noise is a good, modern, loud, booming stereo.

[TTait]

I'm using FatMat, again much cheaper than Dynamat but a comparable product. I'm also installing the Hervey insulation, and a DMCH carpet kit. Photos shortly.

[dmc6960]

I'm using FatMat, again much cheaper than Dynamat but a comparable product. I'm also installing the Hervey insulation, and a DMCH carpet kit. Photos shortly.

!Caution!

FatMat is a cheap asphault knockoff, identical to Peel N Seel. I would not put this in the car.

[Chris 16409]

Is the rubber insulation kit from Hervey the same thickness as the original stuff? I'd like to get it mainly for the parcel shelf, and wanted to know if it sat lower than the two wooden covers for the electronics.

[outatym2001]

Is the rubber insulation kit from Hervey the same thickness as the original stuff?

Yes, it is.
On the parcel shelf you get one foam triangle piece and one rubber triangle piece.
I first removed the old stinky foam on the back wall and parcel shelf and cleaned with danatured alcohol.
Then I put on one layer of Dynamat Extreme on the back wall and one layer on the parcel shelf.
I bought the Dynamat Extreme at full retail price (BOY what a waste of money!). Later I learned of the eDead 120.
On my parcel shelf is one layer of Dynamat Extreme then Hervey’s foam pad then on top Hervey’s rubber pad.