....trying to quieten for stereo stuff- many people here know that I like to minimilize, in part, to keep weight down. I'm ripping the plastic crap off the doors & plan to replace w/some sort of dynamat type stuff. I've shopped around for brands & have seen good deals on Fatmat & several others... Some list the type of base they have like asphalt vs butyl, etc... Anyone know anything about this? Many places say you get better reults by stacking (although I wouldn't do this in many areas) but I would think that using two dif types would be better than doubling up on one type... any input here? Also, what about throwing a layer of the spray stuff underneath the stick-on type, again, only in more noise-prone areas? I'm planning to cover the hatch underneath the carpet, the doors (would like to get something on the furthest inside panel but some say stick-on wont stick well here...???), & I'm removing my rear seat cushion (the rest is gone) to do something like the 968CS/911CS & plan to carpet over the metal bottom, but want something underneath that- this, along w/the trans tunnel, is definately a noisy area, so really need something good there...

I know some here have done things like this w/decent results- I'm wondering more about dif products, etc b/c some are much cheaper than others. I can get 100sq/ft of one type for $100 w/upgraded version of same being about double, but, Dyna Mat Extreme is more than that for about half the amount. Any good suggestions here would be greatly appreciated. I really don't want to add more than ~10lbs to the car for this so I want to maximize my results however I can...

thanks a lot
Robby

 

If you really want to get the cabin silent, it will cost you WAY over 10 pounds! I would pull the carpet up and put a layer under that then put your carpet back over. For the rear I would put at least one layer under all that carpet in the back. Try to plug any holes you might see in the metal as well and try to secure everything down well (spare, jack, etc.).

 

Bose noise-cancelling headphones.

 

Hi,

You do NOT want the asphalt. It is cheaper, but it doesn't work as well and won't adhere as well in the long run. It tends to separate apparently when it gets hot. It also tends to smell. I used it behind my doors and on hot days I can actually smell the stuff. It's also not as flexible and so going over complex contours is a lot tougher.

If you want to keep the weight down you can try using one of the liquid products that spray, roll or brush on. Go to www.quietcoat.com to look at one such example. I haven't tried this so I can't offer any guidance but for someone who wants to keep the weight down I think this is your best bet.

What I will say is that sealing the car and putting the sound deadener in there really does help. One person here on the list said that they used about 3 layers of Dynamat extreme over their whole car and loered noise by 10db which is quite a bit and would make a very noticable difference.

I don't know how good your various seals are - sunroof, hatch, doors, etc but that is another source of noise that should be checked out.

Good luck and let us know how it goes.

Phil

 

I've used the Polyken #360-35 Peel N' Stik roofing tape (4"-12") for years when I can get a good deal on it. It's a 35 mil butyl rubber tape with foil backing and release liner. This stuff works great and is very conformable. It's especially good for stopping radiant heat in the tunnel areas and floor boards. The only drawback is it sticks tenaciously and must be considered permanent. It made my Miata sound like a Jag at highway speeds. I did 3 cars the club liked the improvement so much. They even make a thicker one at 45 mils for those really noisy areas. You can't believe how much it will quiet down the doors. If you are into concourse this isn't the product for you...it does not come off without nuclear intervention.

http://www.tycoadhesives.com/Data/Tr...-FoilTapes.pdf

 

Thanks for the input so far guys...

Steve- where do you get that stuff? Also, 35mil & 50mil, etc... what does this actually mean b/c I know it's not in mm or 50mm would be almost 2" thick... Also, I assume this stuff weighs about the same as Dynamat, etc...?

Mike- I'm just planning on hitting the really bad areas- I know it will add some, etc, but I'm not going too crazy- I'd be willing to go to ~20lbs if it would really make a noticeable difference, but somewhere in there is a limit...

Phil- I'm think I'm going to get some sort of spray-on or paint-on & use underneath the stick-on type in some of the noisier & hard to get to areas. I'm not going to go too crazy here- I wouldn't mind getting some under the carpet on the actual floor, but I don't think I'm willing to go through that much trouble- I'm assuming that would be a lot of work- I really would LOVE to get a layer all the way across & down the entire tranny tunnel but again, I'm assuming that would be a serious PITFA...? I understand the law of diminishing returns & really do want to keep the car light- I'd LOVE to reduce interior noise by 10dB- that would be AMAZING, but I'll bet that guy added well over 100lbs to get that much... I'm not prepared to go that far. If I could drop 3dB I'd be pretty happy, since I've seen ads saying you'd have to double your amp power to get that kind of improvement otherwise- not sure it's true, but...

 

The mils is a term used in coating thickness measurements. 1 mil equals 1000th of an inch. I buy it locally here at a large roofing supply company but also have connections with Polyken through my line of work. Check your local roofing supply houses, they should carry it. The generic Peel n' Stick is imported crap, ask for the Polyken stuff. The foil top layer is great and works almost as well as the lead barriers that serious sound deadening materials use. The butyl rubber is very pliable, doesn't smell, and works excellent to stop a wide frequency range. I think what makes it work so well is that it adheres and molds to complex shapes. The DynaMat products and sheet materials never provide the degree of surface bonding the butyl tapes. Any areas without a 100% bond will still resonate across the air gap and be only partially deadened. The DynaMat that came on the doors of the 83 can be pulled off with very little effort, the bond is that poor. Why spend big money if you aren't getting a 100% bond. Look at the pull-off strength numbers (160 oz/sq. in) on the link and you will see why I say this is a permanent application. There are some cheap Home Depot clones but the Polyken 360-35 or 50 is the best by far. It weighs much less than DynaMat. Keep us posted.

 

Steve- thanks a lot for the input... Butyl is one of the things Dynamat & others use anyway, so if this product is cheaper, sticks better, etc, then that's what I need- especially if it's lighter too... How much does it usually cost? I'll start calling around this week to see what I can get it for here...

thanks again...

 

It's much cheaper if you know a contractor that can buy it for you wholesale. I've seen what they sometimes quote over the counter and it's marked up something awful if they can get away with it. I was getting the 35 mil 6"x50' rolls (25 sq. ft.) for about $15/roll two years ago so I'm sure it's gone up some like everything else in the building trades.

 

I wasn't tring to get you down, just telling you it will cost more then 10 pounds to really get that sound down. Like said before, I know one guy on here lowered it by 10 which is A LOT if you know how they measure sound. Keep us posted because I am SO close to do this to my car as well. It would be worth it to cost 10-20 pounds to lose some noise from my car as well. Let us know what you do, where you put the protection, what kind you use, how much you use as well, that would help me to see how much weight you add. Thanks SO much!

 

Steve- I'll start looking for this stuff this week... BTW- can you give us any idea how much that 25sq ft roll would weigh? Also, are you a contractor? S&H would add something, but if you are, I'd be glad to give you a few bucks for doing it... hell, if it does well, everyone else might want it... you could go in business...

Mike- that's cool- I understand... I just hate to admit that it will take more than 10lbs to really get much & I'm really torn as to how far I'm going to let myself go & am planning to be very careful & choosy as to where I put most of the stuff- trying to be very selective & get the best places, etc... I'll definately let you know- hell, I'd go ahead & start if I could find something really cheap- I've bought at least 4 rolls of the asphalt based Stinger stuff for $15+ per roll- I've wasted at least one full roll (just pulled a big section off my driver door as I need to get in there....) & need so much more, I decided I was not going to keep going like that- going to buy enough to do everything & then some to get a better deal & not be running out, etc...

 

Steve - The tape sounds like an excellent solution but one question: If you use it on the door, what happens when you need to get back inside the door if the tape is permanent???

 

I used something called "gatorskin" or gatorskinz or something in my whole car... while not the lightest, this is an mat with adhesive on the back you must really really press on (must or SHOULD be done in the warm weather) and the stuff is awesome. I think the pack I bought (buy 2, get one free) was like 110.00 and I sold one pack to my friend for 35.00. IF you just wanted to do the hatch (main area for sub) then 1 pack is fine, if you need more (ie doors, floor, rear seats) then you need 2 packs

good luck!!

 

I found this stuff at home depot for 12.00 a roll.

http://www.cofair.com/roof.aspx

It is a rubberized asphalt. I put some on the doors. Does not seem as sticky as the other stuff. Which is good if I need to get in there in the future. I hope it does not smell when it gets hots.

 

That stuff will stink like hell when the first hot day starts cooking your interior. It outgasses and leaves a film on the interior of your glass. It will eventually mellow out but there will as be a residual smell. The pure butyl rubber stuff is the way to go and no smell, but be warned, once it's installed it wont come off. Good luck on the project.