Seth W

You all might recall (pity if you do) that I dynomatted my last car just days before I sold it. Putting that stupid move behind me I have decided to slowly do the same on this car. This time, however, I want to start with the real culprit--the rear wheel arches. I was reading Nichols and a bunch of other 928 sites and saw two suggestions:

1) Using a "closed cell foam" put the stuff in between the wheel arch liner (the black plastic thing) and the body. Use sealing foam (the expanding kind) to really get a tight fit. The closed cell foam wont (allegedly) keep moisture in and it works well. I'm worried about drainage? The expanding sealant (sold at home depot for $4 a can) is not easily directed and likely would have to be trimmed when hardened. I've used it previously to deaden the space underneath the rear seat speaker (a cavern of resonance).

2) Using the stuff that comes in a spray can, clean the underside of the actually metal body well, and build up several layers of the acoustic deadening spray on top of whatever is there from the factory. This is a far more costly option, as a can is like $18.

Anyone who has BTDT? If you have not BTDT, does the first option sound daffy?

Having fun, and still no closer to decision on wheels (but loving the HRE 845! but super $$$)

Seth

Jerry 87 928S4

I used option 1 in only one space when I was adding Brown Bread (sound reduction material). I only put it on the driver's side in front of the rear wheel above the wheel liner. There is quite a cavern in there.

After using the brown bread, I didnt find anywhere else I needed to add the foam.

drnick

has anyone had success with this in terms of a notable reduction in road noise?

Chuck Schreiber

Seth,

You'll probably be happy once you B. Bread the whole cabin. Try this and especially the doors then drive the car. See how it sounds. Then do the fenders if it needs it. I'm doing my 79 with b. bread and I'm anxious to get it on the road to see how it "doesn't sound".

Jim Mayzurk in our local DFW 928 club closed cell foamed his 89GT rear fenders and had good results.

BTW, was at DEVEK a couple weeks ago and had a chance to check out your GT. Very nice!! <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />

SethW@Home

Thanks for the feedback and the compliment Chuck. I'm off to Lowes (Home Depot around here is a zoo) to find closed cell foam.

I'd like to avoid doing the dynomat on the doors until I'm at the stereo stage of the car's development. It makes sense to wait as I'll be needing to replace the window guides, window tint, speakers etc. and that is really a much bigger job than just sound issues.

I was reading Autoweeks last night and looking at the prices of these cars. 360 Modena Challenge. 425 HP--200k. Morgan 8--60k 187hp (?). My 326hp car? A lot less!!

I wonder how long until I really start comitting to the stroker process?

SethW@Home

Shazbot. Lowes did not have the foam I wanted. Bought hot water heater insulation though. Came home and my wife (who is on bedrest in a difficult pregnancy) decided this was the day to get a new kitten (to add to the dog and cat we already have). She puts up with the car thing, and is carrying my child, how could I say no?

The kitten loves v8 german cars though.