Getting ready to partially install my interior (pedals, brake bracket etc) and realized I may need to get my firewall pad in before I do that. I had been planning on using Frost King insulation (link) for thermal and some noise dampening on the interior. Has any one just used that instead of the OEM rubber/jute combo on the firewall? My car won't be a daily driver and is modified so not concerned about correctness, just functionality.
I used the knock-off dynamat type stuff (sticky backed thick foil), was $25 a roll at a local parts house. Covered the firewall with it before I put the AC in. The big sections I also used the foil backed bubble wrap, glued it to the other stuff with 90 weight 3M spray glue.
Seems to have done the trick for me, and the firewall section cost less that $30 that way.
Modified or not I think the best way to go is with a Sound deadner and some kind of heat barrier.
I didn't have much luck with the Frost king stuff my self. It didn't stick very well for me. Others have had great success.
The firewall is something you only want to do once IMO. I would spend the money on some Damplifier Pro or Dynamat first. Your factory firewall pad may still be the best bet for a heat control second. There are other good products for heat but the factory pad is a quick and easy install.
If you going to spend any driving time in the car other then a 1/4 mile at a time it money well spent.
