B-Quiet Brown Bread sound deadener mat. Foil faced, flexible, and easy to install, will hold paint. 2' wide roll. $2 square foot plus actual shipping. Limited amount left. PM me or email a914man@netease.net or call my main business (Q Snap) at 800-867-4712

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brown bread installed in a Nissan. Sorry I don't have a install pic from a 914

Would this material be suitable for use on the firewall inside the engine compartment?

I wouldn't use it like that without mechanical fasteners too. It might be OK, but I'd be concerned that the heat inside the engine bay might make it release over time.

I can tell you for sure, BTDT, I've tried it (on my '67 bus)...No, the butyl will semi-melt and it will fall off. Daily driving it will release in about 3-6 weeks.

Good product, it's just not meant for the engine bay. Should be fine on the interior side of the firewall.

Thanks for the replies, I thought for sure I had found an alternative to that giant sponge for the firewall insulation in the engine bay.

B-Quiet does make a multi layered foam sound mat that I've used for the firewall, but I also used a high quality mylar foil tape to seal the edges. For that install I used cheeshead screws (just like the engine tin screws) and large fender washers to mechanically hold the sound mat, which also had a peel off self adhesive.