A friend of mine has a fox-based Mustang. He mixed some sort of foam and poured it into the frame rails. The stuff turns rock hard and is really light weight with limited expansion.

Given the chassis rigidity our C4s have, has anyone ever tried to inject this stuff in their frame rails.

 

I have been considering it.

 

check with the C3 guy's

 

In the past, it has been a case of 'after you, Alphonse'



If somebody has done it, they have kept mum.

Where would you propose injecting foam on a C4?

.

 

inside the main frame rails.

 

Just make sure its not the expanding foam type. Your frame would look like a hotdog that was microwaved too long.

 

I would be concerned about squeaks from the foam over time.

 

I remember I read all about this solution on the old posts...
The end of the story is that nobody want be the first to try on his c4!
volunteer ??
-Beppe-

 

Could it hold moisture? That would NOT be good if it did.

 

Didn't Mercedes Benz do that to the frames of the S class cars way back in the early 80's??

Water absorption: use closed cell foam like the boat mfg's use for "extra flotation and structural use" the guys like Fountain and Formula use that stuff in the hulls for both of those uses. I had a small Formula and it had some time on it, 3000k hours and the foam never "creaked" or "squeaked" & I used to dry the bottom off very often.

I had to do a hull repair when I bought the boat which involved replacing some of the foam because I had to work inside the hull bottom to correct some impact damage....anyway the stuff Formula used back in the late 80's expands quite a bit. They used to foam the hull bottom after the stringer system was glass in & cured and before they put the cockpit deck on. The stuff expanded and cured and was trimmed back so the deck could sit on the stringers. In more modern boats there is, I think, a way to calculate how much expansion and measure the exact amount of un-cured foam liquid to inject...that's the way it's done now. If any one is tight with a boat designer you could probably get the skinny on what's up with the newer stuff & methods.

Tom

 

GM did use some type of foam in E-body windshield pillars late 70's early 80's? Rust was a side effect after a few years?

 

Ford is using a sound deading foam in their full size pick ups...as for a foam for the frame rails.....I haven't heard anything about it, however; I will look for it at Carlisle in Aug and maybe snap a few pics

 

C4 frame is pretty stout - I doubt foam would make it any stiffer. Foam does help stiffen up a stamped sheetmetal unibody-style chassis.

 

Probably wouldn't hurt anything, however.

Larry
code5coupe

 

Don't know but would be interested in seeing how its done and any results.

 

Volunteers??? I don't think I would be the first to try it, just in the case of the hot dog thing. Lots of damn work to fix.

 

Buy the foam and take it to a nearby 'Pick-a-Part' yard.

Choose a suitable subject, apply and stand well back.
Observe, discuss, repeat.

Report back at oh-ninehundred with your findings.

.

 

Slalom=