Itinerant Air-Cooled

I don't know what the ultimate difference will be, but I had some rust in the rear cargo area that needed some attention. So I decided to go whole hog and install Noico mat.

Before:



Primer:



Matte black paint (still wet):



Noico mat:

DurocShark wrote: ↑

Sun Jan 06, 2019 7:00 pm

I don't know what the ultimate difference will be,
Noico mat:

Well? What IS the ultimate difference?
Colin

Sorry, I don't seem to be getting notifications from here. Grrr...

Noisy exposed engine with a lumpy cam and craptacular Empi exhaust...

HUGE difference! I haven't even done the doors or roof yet. Just the inside.

I even threw together a video!

https://youtu.be/TYxAMh1YFr0

DurocShark wrote: ↑

Thu Mar 07, 2019 6:11 am

HUGE difference!

Before and after audio recordings?
Colin

I actually have some gopro video from before. After I fix my busted throttle cable (stupid Empi linkage) I'll take some after... :)

Ooh ooh ooh, I'm installing an interior in a bus tomorrow, and we have a few pounds of Dynamat for the larger panels and door skins. I'll make sure we get an audio recording before and after, with manual gain and mic placement consistent between takes.

I don't know how people drive their cars with doors that resonate like gongs…
Robbie

I haven't done my doors or roof yet and there's a big difference. Can't wait to get the rest...

asiab3 wrote: ↑

Thu Mar 07, 2019 11:00 pm

A) I'll make sure we get an audio recording before and after, with manual gain and mic placement consistent between takes.

B) I don't know how people drive their cars with doors that resonate like gongs…
Robbie

a) Do you coat the living hell out of every square inch of surface,
or do you follow the directions? (<loaded question)

b) Early buses had a tinny clout upon closing, but the door beam regulations of 1973 allowed just a bead of caulk between the door skin and the beam to quiet things right down.

Waiting For An Audio Old Timey Volkswagen Radio Show.

For me, you can see in the pics I don't do EVERY square inch. Large unsupported panels are where you get the best gains. Factory put tarboard on the pans and inside the rear quarters for that reason. But they had to be all about bang for the buck, so there are still gains to be had if more money and labor are put into it.

In the Guac, I slapped a single 12"x12" square of deadening mat in each door. That alone made a big difference.

DurocShark wrote: ↑

Fri Mar 08, 2019 2:16 pm

Large unsupported panels are where you get the best gains.

We have a winner!

There are two kinds of sound deadening. One is to muffle the "speaker" of large metal panels.
The other, applied with stunning effect in modern Lexuses, is de-coupling the interior surfaces from contact with the metal "speaker" panels. So you dampen the metal speakers with the correct amount of coverage mats, and you throw on some carpet with jute backing, and I have found, oddly enough, that the accordian heater ducts are a huge noise intrusion if you don't have the mesh with filler material like the original ducts have.
Colin

And that's why boxes often sound better than hard mounted speakers.

But I'm more interested in isolating engine noise than anything else. I'm not an audiophile, but a noisy engine can be annoying for more than a quarter mile at a time... ;)

With what I've done so far, a single quiet pack exhaust, and a progressive carb on my 1835, it sounds great. Just a nice deep growl at WOT. Pea shooter exhaust on a stock engine has never sounded good to me. Open that second barrel and you hear both ends of the engine without the high frequency noises that are normally associated with an aircooled engine.

And if you exit the car, many of those high frequency noises are still there. No matter what you do, valve trains on VWs are noisy compared to hydraulics. And without the water jacket and the heavier metal around them, you get far more noise even a few feet away than you do with a "traditional" engine.

I follow the directions; it doesn't do much when applied to small patches of metal. 40% coverage is indistinguishable to my ear from 90% coverage.

Sorry we didn't get around to Dynamat or even a tin can test drive today… Perhaps next week. (We DID get nicely flush aftermarket taillight lenses and housings installed…)
Robbie