Wrapped up my effort at cabin insulation last night, here are a few pics of the project. Many thanks to Logan, John Taddonio, and Frank T for their inspiration on this.

I went a slightly different route on the product used. I chose Prodex - it is 1/4" closed-cell polyethelene foam, sandwiched between foil. It has a claimed R-factor of 15.7, with a noise reduction of 19 db. I got it from http://www.insulation4less.com/ (no affiliation). A 4'X25' roll was $60 plus shipping. My concern with bubble-foil was that it might crush over time in the seating area. Installation was with 3M spray adhesive.

There was no way I could match the intensity of the effort made by Logan and his dad. And... I have new-found appreciation for people in the pattern making profession!!!

I started by thoroughly cleaning the interior and documenting that no rust was being concealed.


Here is a work-in-progress shot of the tunnel area, jute and adhesive residue visible.


Here is the completed rear compartment. I really liked Logan's idea of including the spare tire well - it is like a big drum back there ready to resonate noise into the cabin. My spare cover is like-new and fits flush with the insulation. I notched the alighnment triangle for show.


... and the completed seating area.


By this time the dash was out and I finshed the firewall.


My original firewall mat came out in good shape. A little Armor-All cleaned up the front side and I re-installed it for added noise and heat protection.


Getting closer to being ready for the paint shop!!!

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Jim Arnett
Richardson, Texas
HLS30-15320 12/1970 (original owner)
ZCON 2015 Gold Cup - Street Modified class

What a first-class project! This car is going to be outstanding if you maintain the level of professionalism you've shown this far.

And your car now weighs what? Maybe 4 extra pounds?

Really great job, Jim.

Now you've got me inspired to pull my spare and insulate the well, too.

Frank

looks great. i will be doing exactly the same almost. just waiting to get rid of the rust in my spare tire well.

A wire wheel brush on a drill and a vacuum cleaner will make that an hour's job, Mike. You don't have that much rust in there, from what I saw.

I wish all our carz could look like Jim's.

Jim, can you still smell the spray adhesive in the car?

I got most of it off Frank. I got a rust remover coming to take care of the rest.

Great job Jim! That's the same insulation and adhesive that I used on my car, sooooo easy to work with. Don't let the "thinness" of the material fool you, it does a great job of insulating the cabin.

Making progress! Keep it going ole buddy!

_________________
John Taddonio
1970 240Z
1977 530Z
1984 300ZXT
zcarnut@hotmail.com
FB: Zccr zcarclubofrochester

Frank - no smell of adhesive in the car. After I cut and pre-fitted each piece, I took the insulation outside and sprayed the backside, then back into the garage to place it. All was done one piece at at time to ensure close fit. No nasty smells in the garage and no upset spouse!

Mike - a suggestion on rust tratment. When you get it all wire brushed out or however you do it, treat the bare metal with phosphoric acid to kill all remnants of oxidation and establish a barrier zinc phospate coating. A light wipedown with a dry rag and you will be ready for paint. I have been using POR-15 Metal Ready with great results.

_________________
Jim Arnett
Richardson, Texas
HLS30-15320 12/1970 (original owner)
ZCON 2015 Gold Cup - Street Modified class

To add a little to the thread from past experience:

1) The three things you should be looking to accomplish are dampening harmonics(asphalt/butyl with a constrained layer IE Fatmat, Dynamat, etc), blocking noise and absorbing sound. Doesn't matter if you are going for high end sound quality build or just trying to kill a lil extra road noise.

2) When dealing with a good dampening product(quality butyl with a thick aluminum layer, often times 25% coverage placed well will net 90% of what you would get out of full coverage at a much lower cost/weight. If you are going all out on a full SQ build it is justifiable, but for a sports car with a basic stereo or somebody looking for a quality of life improvement it isn't needed.

3) When you are going to try and block sound out through something like Reflectix, invest in a roll of aluminum flashing tape. Sealing the seams will help out a ton in the battle. The other thing to look into is blocking off any holes that aren't needed either with a layer of damper or with an aluminum/acrylic plate.

4) Look into adding a layer of Ensolite or other quality closed-cell foam. Will help a TON in absorbing road noise, weighs little and with care during installation can easily be worked under carpet/trim/etc. Getting it in the car is as easy as 3M spray adhesive. Easy to use on modern cars in the door panels, but might be a bit tougher under the early Z's door cards.

FWIW as food for thought,
-Cameron

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"We hang the petty thieves and appoint the great ones to public office." -Aesop