View Full Version : Thermo & accoustic insulation

09-04-2006, 05:05 PM
I stripped the old insulation out of my car earlier this summer and well,despite the gain of lower curb weight...the in-cabin sounds are getting my my f-ing nerves aswell and the insane amount of heat radiating from my floor...thank god I don't live in Cali cuz I would have melted. So i'm shopping around looking for a best bang for the buck sound and heat insulator and am now asking for 1st hand accounts on such products. So the most popular products are Thermo-tec and Dynamat extreme, anyone have used either product...your input is appreciated.

09-04-2006, 05:18 PM
What, you dont like the heat radiating from the floor? Should keep your tooties warm in those cold winters up there =P

I had a hot ass floor area in my s13 with sr and a Megan downpipe which ran very close to wall. With stock insulation to boot! I used a bit of exhaust wrap in the areas where it got close and then used some no name stuff I picked up for insulation at ACE.

I dont know what brands are good but I think some of the spray on foam insulators would suit your needs very nicely. Just look for one that is very not dense so that way you arent adding to much weight back but it still should get rid of a lot of noise. Research filling up your "frame" with some of this stuff too, it will get rid of some a that noise and all plus theoretically give you some extra stiffness. There have been some big threads reguarding that either on here or on Freshalloy. Try and find some audio forums too, they will definitely know whats up.

09-04-2006, 07:26 PM
Spray-in bedliner. It's the most expensive way to do it but it's also the best insulation you can get, plus it looks great, easy to clean, and will prevent rust from ever forming. I did my full interior two years ago from the footwells back, covering up every little hole and opening in the sheetmetal beforehand, with the carpet out it looks incredible and feels solid, carpet back in and assembled it's dead quiet. They figure the entire spray job (coating up to the quarter windows, both sides of the rear deck, and the trunk from wall to wall) added maybe 40lbs. Small tradeoff for the benefits you get.
Otherwise, Dynamat is a good choice but is still expensive as hell and requires a ton of prep work to get it to stick, next choice would be regular undercoating but it's messy and won't fully dry on seam glue or other soft products, plus it will turn to mush on the floorboards from the exhaust heat.
Spray foam only works in enclosed places and would do nothing for large areas like the floorboard, transmission tunnel, or back seat. Regular over the counter construction stuff also traps moisture and will eventually cause severe rust in the rocker panels and wheelhouse, leaving you to buy the more expensive automotive type products.