Abomination

I did this quite awhile ago but never posted the pictures or results here. I've been so pleased with it over the last year or so I figured I would post this for anyone contemplating doing this for themselves. What brought this back to the front of my mind was driving my friends brand new 2007 and noticing how loud the car was (stock everything, including exhaust).

Anywhoo...

I love the car to death but the volume inside the car was almost unbearable. I can't have a conversation on the cell phone and on the freeway the music almost has to be full volume to hear it. This was a bigger problem for me than most as I do a lot of work from my cell phone on the drive to and from work.

The majority of the noise, and the most unbearable part, is the road noise. The car has little to no wind noise and the engine/exhaust sounds I don't mind at all. Its the annoying drone/roar on the freeway.

The problem I was having is I want it as quiet as possible without adding to much extra weight to the vehicle. I figured I would make a compromise and add up to 75 pounds to get it comfortable for me.

After lots of research I decided on 3 different products to tame the noise.

http://www.b-quiet.com/lcomp.html

Lcomp is a noise barrier composite consisting of a 1/4" absorber foam with a black urethane film facing, a 15 mil lead barrier and a 1/4" thick foam decoupler. It has a total thickness of 1/2", weighs approximately 1 lb/sq. ft. and it is highly moldable to form to the contours of your vehicle.

http://www.secondskinaudio.com/viewp...10&category=54

This is comparable to dynamat but its 100% butyl rubber (means no smell and no melting) and a much thicker aluminum layer. Figured while I'm trying to kill the noise monster why not tackle the heat monster.

And finally,

http://www.secondskinaudio.com/viewp...13&category=55

this closed cell sponge filters out airborne sound waves that are able to penetrate the layers below it and works in places that L-comp is unable to attach because of weight.

And here she is before I tear her into pieces


One of the weird things with sound is its completely subjective so I wanted a way to measure my results. So I bought an SPL meter. It measures volume



Now on our crappy roads here in vegas these supercar runcraps roar,

These are the current measurements. All windows rolled up, air conditioner off and stereo off.

Idle : 76-80 db
30mph: 90-96 db
75mph: 102-107 db!!!

Thats like a rock concert, and for those of you that dont know every 3db is 2x as loud to the human ear, so 80 db is 1/2 as loud as 83 db.. .sort of lol.

Abomination

Now for the part that scared me, ripping the car down to the bone.

The dash has been shown torn down by many how to guides here.

Abomination

more tear down






Taking the seats out intimidated me the most but it turns out it was very easy, once I took the targa top off that is.

Abomination

Now for the scene that freaked my girlfriend out, a 55k car in pieces lol.

Abomination

Amazingly enough, I could only find 3 pieces of sound dampening material in the whole car, thats pretty impressive its not alot louder than it is.


thats the one piece in the middle there


this is the piece on the passenger side, one just like it on the driver

Guess that explains alot of the noise.

and now, the car gutted!

Abomination

Now to lay some damplifier pro down. This stuff comes in nice rectangular sheets. I'm not sure I got enough to be honest. I didn't realize how much open, flat space the car had.

Now there are 2 main sections to this car, front and rear. The rear is a pain in the ***, its molded like the bed of a pickup truck, so lots of grooves. And the rear tire wells are not only curved but lots of weird stuff attached there and coming off it.



As much as the rear sucks the front rocks. As you can see the floor is one perfectly flat piece of fiberglass, same with the back of the seat area. I put down 2 1/2 pieces on the passenger side



Also, a hint. I had a pair of these emt shears that are used to cut EVERYTHING. Seat belts, sheet metal, plastic, etc etc. It cuts this stuff like butter and doesn't get gummed up like the razor blade does. Plus you dont have to measure and pull it out of the car to cut. You just cut it to size right there.

Abomination

These are "action shots" my girlfriend took of me installing it, I did the entire install in two morning/afternoons. I would say it took me 8 hours total. If I did it again I could do it in probably 5.

Abomination

I had a bit of help along the way



And yes, the poor bastard is fully grown


so, after all the foil backed rubber stuff was down it was time for the other two products. Thats the L-comp and Overkill Pro. The L-comp is a pretty cool material. It has a thick alu layer in the middle with an open cell foam on one side and a closed cell foam on the other. Covered with butyl rubber. I really like the product. I put one full sheet on the drivers floor and one on the passenger floor and the other 2 in the rear hatch.

As for the overkill. It was light enough to use on vertical surfaces so I used 3M spray adhesive for the back wheel wells and for the area behind the front seats. I am also going to layer it over the Vcomp in the back.







As you can see I used aluminum tape to seal things up (I used the same tape on the damplifier material) again to try and fight the heat monster while I was at it.

The overkill pro is really just a light opencell foam, I used spray adhesive on all the vertical surfaces that I couldn't apply the l-comp and applied the overkill.


That back piece is overkill, not carpet.

Abomination

everything fit fine back together.



some things were a bit tight but nothing major at all.

Before

Idle : 76-80 db
30mph: 90-96 db
75mph: 102-107 db!!!

After

Idle : 71-73 db
30mph: 73-78 db
75mph: 75-82 db

I mean its insane, its not even the same car. I took my girlfriend for a ride and she was amazed. We usually took a different car out because of how loud the corvette was but now lol....

Its hard to describe it but all the little rattles are gone, 95% of the tire roar is gone. It still has the nice engine sound but I did lose some of the exhaust sound.

Now as far as materials go. If I did it again I would get more damplifier. I ordered 6 sheets and could have easily used double that. As it is I had to use left over stuff that was not the same quality. That damplifier is probably the best stuff I've used and Ive tried the dynamat and the b-quiet stuff. No comparison.

I also used the L-comp for the car. I cant say enough good things about this stuff. Its a nice sandwich of closed cell foam, open cell foam, butyl rubber and lead, I really think this helped out a lot. I had 4 full sheets and again I really wish I had 6 and I could have covered every vertical spot and the back seat area. As it is I made do.

The overkill pro. I was very unimpressed with this product. Its a very thin layer (you can see through it almost) of foam. I really cant see how this could add any value to the overall sound deadening scheme of things. I would try a different product if I did this again. As it is I used all three sheets. I used one sheet to cover the rear of the car and the other two up front. One for the "waterfall" as the corvette guys call it and one around the transmission tunnel. I applied it only because I figured I already bought it so what the heck.

I didn't show pictures but I also did both doors the same way as the rest of the car.

Overall I'm extremely happy with the results

Wayne88

An impressive job

BriscoCounty

Wow, impressive (and gutsy). I don't think I'd have the guts to rip all that out of my car, but sounds like you knew what you were doing. Good results too.

But sound is a funny thing. I've had so many loud cars before, such as 3 4th gen Z28s, and compared to them, I find the Corvette to be so quiet. I'm amazed at how quiet this thing is. I wondering how much louder it is with the tires you have as compared to the ones I have. I did hear about lots of road noise with the Z51 and that was another reason I didn't get it, but just the base suspension.

And this car does have virtually no wind noise, which really helps. So far, I really haven't heard the tires at all and the stock exhaust is the quietest thing I've ever heard on a V8. I'll be increasing the interior volume sometime this summer via a new exhaust system. As long as there are no rattles and vibrations, then I'm too worried about sound levels. But I also don't do a lot of highway driving, so my needs and yours maybe different.

Anyway, as long as you're happy, thats all that matters. Thanks for the nice write up, sure it'll help a lot of guys out on here. And who knows, maybe I'll need to quiet mine down some day, but for now, it needs to get louder!

SpinMonster

Losing 25db off the volume is impressive as I can compare it to hitting the -20db button on my stereo. I beleive it is actually 3db for the minimum difference a human can hear and 6db is what you register as being 2x as loud. You may have interpreted literature that stated 3db is double the power to make it. 3bd requires 2x the power to produce it so a difference in 3db is achieved going from a 100 watt amplifier to a 200watt amplifier but it isnt double the volume. I consulted Wikipedia.com for the verification of this info if anyone is interested.

Still impressive noise loss. I have the old version of your meter. Mine is analog and I bought it many moons ago. I was more impressed that the duracell battery inside still worked after----9 years.

For those that care about such things, how much would you say you added to the total weight of the car? The coevette is a performance car and is why engineers didnt put any sound deadening material in the first place.

I have a case of dynamat extreme and opted not to use it when the package arrived since it was 75 pounds.

ken-rx

Very impressive. Alot of these mateials are not available now according to the distributors you listed. Do you think all 3 are necessary to get similar results?

Abomination

Ahh yes, I double checked my source and you are correct, 6db is half. Thanks for the compliment on noise loss, your opinion carries a lot of weight with me.

As for the weight, I agree less is more. Thats what kept me from doing this for so long, but it got to the point where I was actually considering buying a new car (ack I know). I actually had a goal in mind and it ended up costing me more money to go as light weight as possible, the total weight of all the product I installed was about 75 pounds. They dynamat you mention is an inferior product with above average advertising (isnt that the case more often than not any more). What adds alot of dynamat and a lot of other companies weight is the use of asphalt, that also gives you that hot tarmac smell. The second skin stuff uses pure butyl rubber, so you can use less and its more effective, plus it comes in at about 1/2 the weight. When I did the rough calculation using the same dynamat stuff (dynamat extreme and dynapad) it would have been almost 180 pounds to do the same install.

75 lbs in the scheme of things was well worth it to me. Also, one big benefit I didn't mention was the huge increase in my A/C system. All that insulation has eliminated any heat from the center console (long tube headers installed), and the ac works about 1/2 as hard (blower speed) to keep me at 72 in 100+ degree heat. One big benefit to that is it also decreases noise since its not working as hard. I really wish the engineers would have saved the 20 pounds somewhere else and added a bit more sound dampening around the wheel wells, but they didnt

Abomination

It is all available except the l-comp which second skin will begin producing a replacement for and a few other brands have comparable products.

And no you don't need to go to the extremes but they all do different things. The damplifier (dynamat stuff) takes vibrations (noise vibrates stuff) and turns it into heat. The l-comp absorbs the lower frequency noises and slows down the higher frequency and the overkill blocks high frequency noises. So its the combo of products that produced such an amazing difference in volume.

But the damplifier by itself only covering 70% of the vehicle would do about 85% of what 100% coverage and all three materials did. Its the extra 15% that is all the work and $$$ (isnt that true with everything though?)

BDillon

Thanks for taking the time and effort to put this writeup together.
I have an 08 on order and I plan on doing something similar.
I was looking at the kit from Exotic Vette but I don't know what it is made out of.
Thier website says it only weighs 7lbs.
It is too bad that according to the website they no longer sell LComp.

xfiremd

How thick do you think all that sound deading is? You you think it has change you petal throw at all?

Abomination

Well in spots that got full coverage (horizontal) I would say 1/2 an inch. As far as petal throw I guess I dont know what your asking, the seats are in the exact same spot... I guess my heel is 1/2" higher.... but no difference in the way the car drives.

Raville

Well done on the job! As most of us with wives we have to think about the cost. Already got a few things past her Like "Hey the Vararam is on sale and it will improve on gas mileage" ( just put it on last nite)

The less heat thing will be a seller if the price is right

So if you don't mind what did the total project cost ya?

Abomination

About 350 to do all three products, there are less expensive products but you get what you pay for.