Anyone have any experiences in improving the sound proofing in the 914 ?... I have a 74 1.8 liter that is my semi daily driver and the Engine Bay Insulation peice as well as the insulation panel behind the backpanel is missing.

I am looking at replacing the engine insulation panel with one of those foil types that is avail on ebay !

George at AA recomended the stock stuff.... I saw in the October VW Trends mag they are "soundproofing" a bug using a multi-layer foil product called Dyanamat. www.dynamat.com.

The stuff has a neoprene rubber base layer a 8 mil lead sound deadening layer and a foil outer layer..

My plan was to use this stuff on the backpanel/firewall as well as the floor and on the inside of the doors glued to the inside of the steel door panels. I was hoping to get the car quiet enough to be able to install a CD Player/satellite radio with Amp and Speakers in door panels.

The car handles like all get out... just trying to make it more comfortable to drive and be able to enjoy a modern sound system.

any thoughts or ideas on the soundproofing or the sound sytem / speakers ?

rob wellner

Strip all of the stuff in the engine bay and deal with the sound/heat reducing stuff on the inside. Remove everything you can in the engine bay!! I have found out that it is more important to protect the internal body of the car. Clean the engine compartment as best you can and then paint the thing with really good (Chime in all the paint Gurus) Paint. It will be well worth it it the short run, let aone the long one.

I have used X-mat (about identical to dyna-mat) on all my vehicles that are running. 914 isn't one of them yet. On the doors, remove the door panels, cover all the area behind them on the doors, put em back on. You should make sure that your back glass and door/window seals are all tight before doing the inside firewall or floor. you dont want water to find a place to sit. The more you use, the better, don't be stingy with it. I saw a product called "lizard skin" used on horsepower tv a couple of weeks back on their 55' fiberglass body. If'n i remember right, they said that tiny air bubbles are trapped throughout it when it is sprayed on to absorb sound and heat. might be something worth trying.

If you're thinking of cutting your door panels, please don't.

One of our members, morphenspectra, makes a replacement for the stock speaker pod which will accommodate a 6.5" speaker.

I've used dynamat a lot on my car. It's easy to use. I've used it in the engine compartment, behind the back pad and on the floor. When I rebuild the doors I will use it there as well. The only drawback if you're concerned about it can be the added weight.
Cheers, Elliot

I've installed the shiney stuff. Put a piece on the back side of the engine lid as well. I'm not sure I agree with Headrage, I think you need absortive material in there. I'm not sure on the durability of it yet though.
But what worked more than anything else was going over the engine tin and heat exchangers tightening all the loose stuff. Also getting the window lined up well and replacing that inner fuzzy strip stopped my windows from rattling. All these things were a lot looser than I thought would be the case until I started checking especially the cooling tin under the cylinders and up to the h/e.

So, does this mean it's pretty heavy? I've thought about using it, but have never actually had any to see/touch, so I don't know how much it weighs.

I used dynamat on my Honda and it got rid of vibration (buzzy) noise in metal panels but did little to nothing for sound deadening. I could hear the exhaust and road noise crystal clear even though I had two layers on the floor and in the doors.

For real sound-proofing, you need some kind of foam or other thick material (like the old woven mat they used stock on the later 914s). The Dynamat and similar things will help some, as any large flat-ish panel will act as a speaker when vibrating because of transmitted engine vibration or the like. However, Dynamat won't help much with engine or road noise, unless you really pile it on thick (several layers). A great deal of noise is transmitted because of poor seals. Old, age-hardened window seals don't cut out the noise nearly so well as pliable seals (nor do they hold out the rain). Any hole or gap will transmit an incredible amount of noise. The back glass is loose in a lot of cars, and needs to be re-stuck. Just fixing the door and window seals will help quite a bit.

I Dyna Matted my firewall on both sides, it helped some, but not what I expected. As far as weight goes, I bought one of the Dyna Mat kits with 10 big sheets in it, and the whole box weighed 21 pounds. I used less than half to do the firewall. I also did the area in front trunk, behind the gas tank. The thing that is for sure, it's tough to make a 914 seem like a more modern PORSCHE when it come to intierior noise level....

On the last project car I did, we used B-Quiet "Brown Bread". It's lots cheaper than Dynamat, and a very good product.

We also used the B-Quiet "H-Liner" to replace the factory sound pad on the engine side of the upper firewall.

I've got lots of the "Brown Bread" in stock. PM me if you want some.

http://www.b-quiet.com

Trying to quiet a 914 sounds like a losing battle. I'd think the easiest solution would be to use a quieter muffler and stock air cleaner. I'd use the stuff to get rid of specific vibrations or rattles but I wouldn't bother with a complete sound deadening effort on a 914.

In my 911 the previous owner had installed multple layers of foam on the floors and get this, in the front trunk. I'm not sure what kind of sound from the front trunk in a 911 he was trying to deaden. Anyway, I removed it all and I noticed zero before and after difference.

I used Dynamat Extreme on the entire interior floor, firewall, & sills, covered with DynaLiner on the floors & ExtremeLiner on the firewall.

HUGE imporovement even with the top off. Top off windows up, very queit, top on it is quieter than my Boxster except for the sweet induction roar of the Webbers on the 2270. The materials are also supposed to help keep engine heat out of the cabin, etc.

I used NexTag or one of the similar services and was able to purchase all of my Dynamat materials at less than 50% of sticker price. I bought the Bulk Pack of the Dynamat Extreme, 2 "wedge-paks" of DynaLiner, and one sheet of Extremeliner. Exactly enough to do the entire interior of the car.

Buy a little wooden roller, it really helps with the install and plan on going through about 3-4 razor blades cutting the Dynamat and buy some crappy scissors for the Dynaliner.

Oh, i forgot that when my 914 was running, i used x-mat on the targa top, then glued a piece of headliner material to cover it all up. helped a good bit, especially when driving in the rain.

Also might want to check out Raammat (www.raamaudio.com). Cheaper than dynamat, and just as good, plus they offer a foam that I have had very good results with. Quieted up my subaru quite nicely (doors made of tin, I swear)

mcmastercarr.com has some real good stuff for on the cheap too. Used some adhesive backed stuff from there in my Beetle, worked great!

-Chris