Tales of the magic foam (kind a long)

[aki hirota]

Some of you have read the article about Autoseal foam in Sports Compact Car
magazine. I haven't, but I have read a lot about stiffening the chassis by
injecting expanding foam into the rocker panel.  After a long thought about
doing this, I finally did it over this weekend on my b-13. Foam I used was
the ITW foamseal (www.itwfoamseal.com/auto_aftermarket.htm).  The toughest
part of the process was to make bypass drainage for water coming down from
the sunroof.  I ended up drilling a 1/4" hole at the bottom of A-pillar and
plastic tube and fittings.

I thought I made a big mistake using this foam because unlike other foams I
read about in numerous Japanese websites, this foam is not that hard at all
when it is cured.  You can still squish cured foam with your fingers! It is
very unlikely that soft foam can add stiffness.  So after waited for
overnight, I reluctantly went for test drive.  The bump shock seemed a
little less than before, I noticed.  Then, at 60mph, there is almost no road
noise audible in the cabin. It made the car so much quieter!  But did it
make the car stiffer? I still don't know.  Bump shocks seem much less, but
it may well be because car is quieter, not because car is stiffer. Handling
seems a bit sharper too, but it maybe because I want to believe so.

So the conclusion.  If you want to make your car quieter, this is definitely
worth the cost.  It takes only two set of the foam which costs $72 ( I
bought 5set because I didn't know how much I needed). If you don't have a
sunroof, the procedure is very simple. If you want to make your car stiffer,
you may want to import the foam from Japan. Bellco is the one started all
this (http://www.sun-inet.or.jp/~bellco/).  I am trying to talk to some tech
person at ITW foamseal about the physics behind stiffening chassis with not
so stiff foam.

AKI
'93 black classic w/120,000 miles