Dynamat

It's a good product (see "megs '57' thread for extensive application).

No knowledge of 348 specific issues..

 

I haven't used it on my Ferraris, but I treated my 85 Corvette with it extensively. Nothing makes noise like an 80's Corvette and the difference was impressive. It is expensive and heavy, but worth it if noise control is your goal. On many places on the Corvette I did double layers as the mass of the sheet is what works best at reducing noise transmission.

When I worked at Crutchfield we used/sold a lot of it with high-end stereo installs to quiet vibrating rear decks, trunk lids, license plates, etc. Works well.

If you don't already have one, buy a heat gun like you'd use with electronics shrink-tube. Aside from making the adhesive more aggressive, it also makes the Dynamat much easier to mold into shapes. It is more-or-less an asphalt type material and laying it on a surface doesn't make it effective - it has to adhere to it as much as possible.

They have even expanded into home treatments now. When I build my home theater I intend to use their treatments behind the sheetrock to reduce the irritated wife factor on movies like Jurassic Park resulting from excessive subwoofer exercise...

 

I got good results with it on the bulkhead behind the seats. I removed the automatic seatbelt tracks and motors since they weren't functioning anyway as it opened more surface area for mat placement. You can but the mat at Best Buy. It's pretty easy to work with

 

I think so. It's a little complicated. I've got a Spider and although it's sounds great with the top down, now that the weather's cooler and I put the top up, it seemed kind of noisy inside. It made 2 changes at once so I can't definatively say what made the difference. I Dyamated the bulkhead, but I also made a fleece lining for inside the convertable top. Combined it made a huge difference. I suspect they both added about 50% to the final effect, but can't say for sure. The dynamat is pretty cheap ( like $50) and so easy to install, it's worth a go.

 

I didn't remove any carpet. Just pulled the big access panel off that covers the bulkhead with the computers behind it. You can tuck the Dynamat down behind the carpet to the level of the floor pan, and then up to the carpet trim below the back window( at least on the Spider ). I didn't pull the seats and carpet out to do the floor pan. Just trim the Dynamat around the computer modules. You can struggle with trying do do the Dynamat in one solid piece, but the adhesive works so well against the steel that it's a lot easier to cut into smaller pieces and stick it on as needed.

 

Guy across the street just did the inside of his 67' GTO with the stuff and its VERY nice. Best put down with a semi-hard rubber roller. He got it off of Amazon.com and a really nice price. (I forget how many panels came in the box). But get their seam roller at the same time.

 

I have Eastwoods brand with a roller. I have only put it in the door, so's to get a more solid sounding shut. I will do the floor pan later to stop some of the road noises.
It's quite cheap from Eastwoods and a great product.

 

I did a complete carpet replacement and interior soundproffing project on my 308GTSQV a couple of years ago. I wrote a complete how to article on it and it was published in Prancing Horse a while back. I used a two layer soundproofing system from www.edesignaudio.com I would be happy to email you a copy of the article which includes pictures. It made a significant difference in the road noise and comfort in my 308. I sold that car and now have a 348 TS SS but there is no need to improve the quietness in my 348. PM me with your email address if you want the article. If there is a way to upload it to FChat I would do that. It is 9 pages long in a "Word" file.
Mike
Reading, PA