How hard to remove carpets? - Installing Dynamat
 

I'm thinking about installing Dynamat as my wife says the '87 911 is too noisy. How hard is removing and re-installing the seats, door panels and carpet. This will be my 2nd project on the car.

Also, any experience with the Dynamat Extreme?

Thanks for your help.

It would be cheaper and easier to buy earplugs for your wife. ;-)

Mine says that my 87 is a little loud too. At which point I say, "Huh?" and smile.

Most of the noise comes in through the rear. What is the condition of your engine soundpad? There is a lot of deadening material (I think) under the rear seats as well. You could also just double layer your floor mats (buy new ones, put them on top of old ones, especially in the rear) so you could pull them out for spirited driving.

Earplugs won't work...I suggested that, too.

She wants Bose noise cancelling head phones, at least.

The sound pad in the engine is good. It appears that it's alot of road noise that is bothering her. I'm not planning on using the car on the track for anything other than MAYBE some DE's so I'm not overly concerned about the added weight. Also, that's why I'm considering the Dynamax Extreme...it's lighter.

If there are any other good suggestions, I'm game.

Thanks.

try doing a "search" for Dynamat"..................Ron

Dave:

I did this last year and am very glad I did so. It's still loud, but it's drivable now with "company' :D

Anyway, it's not too difficult to do what you want, I'd say you can do teh whole thing in a couple of weekends, inlcuding time to steam clean everythign while its out, hide food your seats if need be, and general detail while it's easy. If you just pull and go, A weekend.

Also, consider checking on EBAY for Dynamat deals. I bought a 100 SQFT bulk roll for 59$ last year and only used 1/2 of it.

Let me know if you have any questions.

Enjoy!

Chuck

Chuck,
Thanks....I'll for sure give it a try.

My wife's family doesn't know which end of a screwdriver to use so she gets a little nervous when I talk about taking out the interior. She didn't know me in the 60's when I rebuilt a 356B when everyone thought it was a VW. Since we've been married (16yrs) I haven't had a fun car to work on...but I have one now!

Boy, I wish I had that 356 now!

Dave,

This is not difficult. There is an article somewhere on Pelican on how to remove the door panels. There are 4 bolts holding each front seat. You have to slide the seat forward/backwards to get to all of them. The carpet is glued in some places, so you need some glue to put it back again.

This winter I will be using a liquid product called Noise Killer on my car. Recommended by a friend. Easy to spray (or brush) on and light. Available at car stereo shops. If you are using heavy asphalt mats, you can cut the mats into 2" wide pieces and mount those 1" - 2" apart to reduce weight and/or cover a larger area.

If you are not doing the whole car I suggest you start with the floor (front/footwell) and inside the doors. The roof is harder to get to, but should be considered. Knock on the metal on various places of your car with your hand. A "clunk"- sound indicates vibration. Do those areas, and you will reduce the road noise. A more solid, dead feel will tell you that the area is well insulated/soundproofed. :)

Dave,

If the Dynamat doesn't work look at your tires. What kind of tires do you have, BTW? Some tires are much louder than others, also if you are running higher than recommended tire pressures, that might transmit more road noise.

Just a thought.

Dynamat can smell bad on a hot day. I put in dynamat on my BMW to cure a sunroof/headliner rattle problem. On hot days, the Dynamat smell is very strong. Takes a while for the car to stop smelling on hot days.

You don't want to change the comment from "This car's loud!" to "This car stinks!"

---
anthony

Hey Dave...the '87 is relatively quiet for a 911..and the low frequencys from the exhaust, etc. are difficult to remove..the higher frequencys from tranny or the road noise from doors and floor are easy..the problem is that your exhaust will sound cleaner/like heavy duty rumble and you will want to upgrade your exhaust system into a VERY heavy duty rumble, IMHO.........Ron

RoninLB,
I figured the engine & exhaust sounds (not noise) would still be there. It is the stuff from the road. I had a 73 911T years ago and it was louder than this but maybe I'm just getting soft in my old age.

Should I shy away from doing this?

Thanks.

I also get road thumping and vibration - bad roads especially. Think about how these noises are getting into your car. A year ago I ran SP800's and they were noiser than the PZero's I have now. In what shape are your suspension bushings? Maybe that's a better fix - and more rewarding.

Dave...I pulled doors apart and removed window to do a full sheet of Dynamat on door skin..it sounds heavy duty when you close it.other 911 guys hear it and open and slam the door a few times and say "good door alignment".I did the floor interior and tranny tunnel when engine was out. no tranny noise anymore...I did engine lid to eliminate sympathetic harmonics/tin can vibrations..it was worth it to me because I use high end 6 1/2in. door speakers and don't need no stinken tin can noise... but don't look for big noise reduction..more like a different noise..more like a thump than a ping...and not for nothing, but w/sunroof open and windows closed it is 90dB at ear level, w/quiet S-03s and an old stock muffler..the noise sounds "cleaner"..a lot of $$ and time..you really have to want to do it..and your bride will not be happy w/the results..I used the expensive model Dynamat w/foil................Ron
http://www.pelicanparts.com/support/smileys/drummer.gif

I saw a tee-shirt long ago that said "if it's too loud, you're too old". :) My '72 is pretty loud. I set a Camaro's alarm off on Monday just cruising by it in the parking garage.

My firewall noise insulation rotted away long ago. So I took the stereo speakers out. That 2.8L at 7000 rpm sounds awfully good! :D

Greg

Ron - I think I'll take your advice and look at the tires, suspension bushings and bearings. I'm being premature with the Dynamat until I've reduced the noise sources.....I've been in safety and Industrial hygiene all my life and getting rid of the source is the first thing we do in business. I guess I got the "red mist" like I did when I was racing. I'll try that stuff first and then may get back to you on the dynamat.

Everyone...thanks for your advice. It kept me from jumping ahead of myself. I've just rejoined the 911 ranks and I can't believe all of the help that's out there. I'm going to be needing it .

Dave SmileWavy http://www.pelicanparts.com/support/smileys/clap.gif

Hey Dave,

I had the opposite problem: my car and I both felt that my wife was too loud...we solved the problem. The simple fix was to give her the house, move to another state and start our life over with someone new who would appreciate us...we were a package deal! :D :D :D

;)

Ryan




1974 911 2.7 CIS coupe w/sunroof

Ryan,
The wife's a keeper....

I'll work on the sources and as a last resort go to the dynamat. I also think she isn't used to sports car sounds. She likes her Explorer and my 90 MB (which is like driving while sitting in a living room chair. Nice for some things.). While driving it back from Detroit, where I bought it, whe mentioned the noise and I'd just like to minimize it for her. It isn't a deal breaker! With her, that is.

See Ya.

Dave

Get the Bose noise cancelling head phones, that way you will not have to talk to her while you are in the car, so you can concentrate on your driving, of course.

Drew - Got a pair....my best friend is Dir. of Mfg Eng for Bose. They are incredible. I wish I could install a system in the whole car.

Dave

Dave,

I would do the floor, from the front seats and forward. I think this is a high resonance area (Knock on the area and you'll see what I mean). Adding some Dynamat here (under the carpet mats in the footwell) could be done in an hour. :)

If you notice a difference, you could do the same thing on the transmission access cover in front of the back seat.
Use a heat gun to heat the mat and the metal. Makes it easier to fit the mat.

Dave, the interior itself comes apart pretty easily as stated above. If you need a hand give me a shout, I'd be happy to help another member pull apart his 911 and maybe put most of it back together. :D

I feel a poll coming on:

Post a pic of the wife and the car. We'll decide which to keep

But for what a divorce will cost you could probably upgrade to a new 996

I also have a pair of the Bose noise cancelling headphones that I wear flying overseas - and they are incredible. They definitely reduce fatique, and when you listen to movies/music, are spectacular.

Bose noise cancel in the whole car?
 

Hmmmm... I wonder if you ran it through an amplifier?! Would it work for the whole car? Intrigueing!

I found some sound deadening materials in the footwell of my old Mk2 VW Golf.

These are rectangular, about 200mm x 450mm long x 3-4mm thick, and look like a grid of small squares filled with sand or something similar - and so are pretty heavy/dense - so I presume they'd be good for sound/vibration reduction.

There are two in each footwell of the Golf ( but if the car has been standing in a dismantlers yard for a while the footwells are bound to be full of water! - so pain to get these pads out.

What is Dynamat made of?

Carpet fitters near me sold me some heavy duty carpet underlay which is about 5-6mm thinck dense rubber - and is very, very cheap.SmileWavy

Have you thought about a new wife?

can't give you hard info.. but Dynamat cuts the higher frequencys. I tried to describe it in a previous reply here to this.. it is expensive.. a same type stuff is called Brown Bread, and is much cheaper.. the carpet stuff may help a little.. our co-member "bell" knows more about this than me.. maybe PM him a message.. and a "Steve W" from Calif is very knowledgeable also.. I know there is another audio pro around here, but can't remember who without a search of audio topics..............Ron

hey i'm here :)
it's not so much the dynamat itself, it's the physics behind it.
what happens is when you apply dynamat you are actually changing the resonant frequency of the metal it's attatched to, creating a more dense panel which will vibrate at a much lower frequency eliminating the tinny rattles. it must be applied thouroughly though, you need to clean the surface smooth and make sure it sticks and conforms to the panel everywhere it touches it. if it does not it will not change the resonating frequncy as effectivly.
i've used dynamat original and some other off-brands that were half the money with the same results, how good it's going to work all comes down to the installation.

I've wondered about this for a while and whether it's worth spending the $$$ for acoustic negation/suppression. I went the cheapo route ($40/big roll of tar from Harbor freight and BTW I have way too much extra in case anyone needs some) but haven't tested the results. The theory was on the panel tap and listen for the echo. Damn the weight, full speed ahead.

Don't they have a reverse waveform generator to help people sleep for less money? (not that it would actually work in the complex folds of sheetmetal)

If the majority of the "road noise" is coming from the fenders(most friction, ears forward) could be isolated from resonating and the rest could be ignored without too much effort, there are probably bushing creaks, panel flex/rubbing, and drivetrain harmonics that are showing up in the passenger compartment far from the original source.

Someone posted about a spray-on dampner and also about using the thin foam underflooring that goes under Pergo. Doubled up might make selective results without space/weight loss. A professional type under-carpet padding does wonders for the preceived creaks which signify an aluminum-can-crush framework.

Someone who works in a music studio that has access to digital waveform meters could measure different acoustics under driving conditions and give hard data to what works best.