Hervey’s sound dampening kit? Get from “ken”?

[FABombjoy]

Butyl tapes are great for killing panel resonance. There is a lot of panel resonance in this car, so this is helpful.

There is a lot written on the subject of sound dampening / damping / deadening but these are helpful:
https://www.sounddeadenershowdown.com/products
https://knowledge.sonicelectronix.co...mpening-guide/

Exclusively using butyl sheets tapes may not the optimal strategy. Butyl to limit fiberglass panel resonance but use a foam/vinyl combo on top to really block sound. The factory carpet foam with rubber top in the firewall area was on the right track. I rebuilt the "foam triangle" between the fusepanel / ECU tray with carpet pad & dense rubber mat - this matched the height of the original piece. Then installed some closed-cell foam / mass load vinyl along the firewall and the engine noise is noticeably reduced. I'll be pulling the old carpet pad from under the seats and replacing with MLV/CCF, too, so see if further reductions in wind/road noise are possible.

[dn010]

Butyl tapes are great for killing panel resonance. There is a lot of panel resonance in this car, so this is helpful.

There is a lot written on the subject of sound dampening / damping / deadening but these are helpful:
https://www.sounddeadenershowdown.com/products
https://knowledge.sonicelectronix.co...mpening-guide/

Exclusively using butyl sheets tapes may not the optimal strategy. Butyl to limit fiberglass panel resonance but use a foam/vinyl combo on top to really block sound. The factory carpet foam with rubber top in the firewall area was on the right track. I rebuilt the "foam triangle" between the fusepanel / ECU tray with carpet pad & dense rubber mat - this matched the height of the original piece. Then installed some closed-cell foam / mass load vinyl along the firewall and the engine noise is noticeably reduced. I'll be pulling the old carpet pad from under the seats and replacing with MLV/CCF, too, so see if further reductions in wind/road noise are possible.

Thanks for posting that, the engine noise is so loud in my car I'm dying to find a way to quiet it down. And to think 15 years ago I actually enjoyed all the noise...

[FABombjoy]

I do have a "before" recording - I'll try to get an "after" as well.

Unfortunately the before-recording has the sounds of an open wastegate dump and is on my old tires / wheels. There may be enough cruising for a reasonable comparison. The sound goal is "civilized touring performance" so I've been happy to add some weight in exchange for pleasant long-distance cruising. Having stock manifolds -> turbo -> muffler will almost always be a much quieter than any header setup.

I have a huge roll of MLV/CCF for the interior. This is the side profile.
MLV-parcel-blanket.jpg

A layer cut to fit the rear parcel panel.
MLV-foam-back-board.jpg

Old -vs- new engine/trans "triangle" pad under the parcel shelf carpet
Old-vs-New-Padding.jpg

The triangle is just this:
https://www.homedepot.com/p/TrafficM...0113/301153300
contact cemented to:
https://www.homedepot.com/p/StepAhea...8-33/202616234

And then another layer of MLV/CCF cut to the same size as the loose parcel carpet over top.

The hollow areas behind the parcel are also stuffed with odds and ends of loose carpet foam

I could have used MLV/CCF exclusively for the triangle pad, but I tend to use the parcel area a lot. With the amount of foam needed to level-out the surface relative to the ECU and fuse covers I was concerned about heavy items causing a Tempur-Pedic effect and leaving dents/divots in the surface

[David T]

One way to install sound deadening is to use strips of the rubber to add mass to the panel so it won't resonate. Cover with closed cell foam. Could take some experimentation to get it optimized but you can wind up with a better, cheaper job with less weight. You should also use metal foil to help insulate and reduce thermal conduction. As long as you are dong this, anything you can do to help the A/C is a good thing! Make sure any openings are well sealed so sound can't get in easily. If the motor is very noisy maybe you need exhaust manifold gaskets?

[iflights]

Agreed on doing some heat reduction work while you are at it. I found this site which has some interesting solutions for our heat challenges.

Have not used any of their products, but seriously thinking about it.

https://www.heatshieldproducts.com/automotive