Dynamat in 2012 GT500 questions on reducing NVH

[_mach_]

After a 2000 mile road trip over the holidays, the interior NVH is just driving me nuts, so I went ahead and pulled the trigger on dynamat extreme. I have a MGW Gen2 shifter, 1 piece driveshaft shop aluminum driveshaft, and billet LCA's with rubber bushings.

I ordered 2 bulk packs of dynamat extreme, total of 72 sq ft. I'm wondering if anyone has done this in a newer GT500, and approx how much you used?

I'm planning on doing the trunk, rear deck, under the back seats, and floor boards and tunnel. My hope is to reduce the NVH from the 1 piece drive shaft and LCA's as well as rattles from the stereo. Has anyone done dynamat to get rid of NVH, any tips or tricks, or places to focus on? I have awful noise coming from the rear end with the 1 piece aluminum drive shaft, lots of rear end whine between 50-65, lots of transmission noise (all gears, increases with speed) etc.

I plan on starting the project by pulling the interior tonight, so any help would be much appreciated!

 

[TVS VERT]

Just ordered a bunch from summit racing as well to help with the same issues u have

 

[_mach_]

I really hope this will do the trick, how much did you order?

 

[barspen]

I'm surprised you are getting that much extra NVH from the 1-piece DS. I noticed a little more NHV with the LCA's, but nothing crazy. Is you pinion angle OK? All your bolts torqued up right with your mods?

I used a little Dynomat under my shift boot to stop some of the extra NVH in the transmission\shifter after some mods. It helped, but noise still travels through the solid objects (shift stick), so it was minimal.

Good luck!

 

[enormous]

You will notice a difference. I use 80 sq. feet of DM and covered the entire bottom and sides of the trunk, under the back seat, next I removed the front seats and lifted the carpet and covered the sides of the tunnel and almost up to the firewall. With the remaining material I covered the inside of both doors in smaller cut pieces.

Cut proof gloves (very important) and a sharp blade is all that is needed if my memory is correct.

 

[_mach_]

I ordered 72 sq ft and I already have about 10 at home, so that should be just enough to do it all.

@barspen, I think I had a rather loud transmission to begin with, as the same noise I heard before the driveshaft is now much louder with the 1 piece and LCA's. I did have some warranty work done on the transmission right before I put the KB and 1 piece on, so wondering if something inside the trans is just really loud... I hear a lot of whine between 50-65, and I have a "womp womp womp" that gets louder and faster as I speed up, and it's definitely in the transmission, as I can put in neutral or press the clutch and it'll quiet down significantly. I pulled the driveshaft and clocked it 180* and have the same sound, but didn't clock the adapter, maybe it has something to do with the adapter being 180* off?

I didn't change the ride height, so didn't think to check pinion angle, but may look into that this weekend.

Thanks for the info

 

[timtang]

Last year I installed a similar product called "B" Quiet, a Canadian product. It installs the same. The product is offered in 1ft by 50ft rolls-I used 2 1/2 rolls. I was about to install the Shelby/Kicker stereo with the trunk sub but I was also feed up with road noise so I installed the product while doing the stereo. The entire inside of my 2011 GT 500 is done except the roof. I also put their sound deadening material from the firewall to the rear seat floor pan. The result is exactly what I wanted. No more road noise and easy temp control in the car. I have no suspension mods at this time however I believe you will be very happy with your results. I also put the product inside the doors directly on the door skins. Quality sound when closing the doors. I do have mods planned including suspension and power/ headers but for now waiting out the warranty. You won't be sorry you did it..

 

[finally03gt]

If you guys think these cars are loud, you should cruise around in a 2003 GT with 3.73's (that have a little whine) Eibach pro springs, CC plates, and a pro-thane bushing kit..haha. I'm still trying to sell the '03 and transitioning from that to the Shelby is a trip. That said, oddly enough, that car still does alot of things realllly well. But I'm still sticking with the Shelby.

 

[biminiLX]

I've had success with Lizard Skin ceramic.
I had my Fox sprayed when the cage and minitubs were done, worked great as an alternative to dynamat.
Just a suggestion if guys have the trans or rear-end/suspension etc. out.
-J

 

[_mach_]

Progress after about 7 hrs last night, I got the trunk, deck and back seats done, tonight I'll work on the area under the rear seats, and start on the doors...this is very time consuming, but seems to be making a pretty big difference so far

 

[enormous]

Looks great! You need small pieces and fingers like a raccoon for the doors.

 

[jonw605]

I don't have much experience with dynomat but I know its kind of heavy. Do you know about how much weight this is adding to the car? I'm sure it's worth the benefits of the sound deadening, but I'm curious.

 

[jonw605]

Is that blue moon you're drinking?

 

[biminiLX]

I don't have much experience with dynomat but I know its kind of heavy. Do you know about how much weight this is adding to the car? I'm sure it's worth the benefits of the sound deadening, but I'm curious.

Also wondering this. Its definitely weight in the right place, but still curious.
What was the shipping weight of the package you used?
I might do this when we install the rear ice box.
Looks great so far!
-J

 

[99SSls1]

Holy serious!

 

[_mach_]

It's Sam Adams Cold Snap, WAY better than Blue Moon...although I should have bought cheap beer...dynamat is expensive!

I installed about 65 sq ft of dynamat so the total weight is about 32 lbs, shipping weight on 72 sq ft was 35lbs (17.5 per bulk pack).

Here's the progress. I was able to do the trunk, rear deck (top and bottom) all the back and under the rear seats, I brought the dynamat up to the front of the rear seats, even got the area around the quarter windows and both sides. I am going to do the doors next, but will likely run out of the 72 sq ft I originally ordered. If there's still a lot of noise, I'll dynamat under the driver and passenger seats, and over the tunnel. I'm really pleased with the sound quality inside the car (I have diamond audio D6 components and 2 alpine type R 10's in the trunk) I get better sound quality at a lower volume. It's raining here and I just waxed the car, so I'm going to wait until the weather clears up before a test drive.

 

[BossAnaki]

Waiting on your final thoughts after its all done.

 

[_mach_]

me too!

 

[jonw605]

Looks like you did a nice job mach! That's way less weight then I was thinking. My guess was closer to 100lbs.
I've had the sam adams cold snap. Its good beer.
Cheers

 

[_mach_]

Thanks man, it took a lot of time, and I'm sore as hell from crawling around in the trunk and back seats, but hopefully it's worth it. To anyone doing this job, I recommend knee pads (my knees are all cut up from whacking bolts and stuff) and some very thick nitrile gloves, my hands are all scabbed up from all the sharp metal edges and reaching thru holes etc.

I got the interior back in, and you can immediately tell that the car feels more solid, and it sounds way different in the cabin...less vibration and noise from the outside. I will be re-tuning the stereo stuff tonight so I'll report back on the in car acoustics soon.