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View Full Version : Chassis foam, interesting stuff..



Jrgunn5150
03-08-2008, 09:32 PM
So I was reading up on why import guy's don't use subframe connectors ( I still have no idea, lol ) , But I came acrossed this story about filling the subframe and chassis with a special type of expanding foam. The maker's claim a 40% increase in chassis rigidity, and the couple of guy's I could find who did it said the interior is quieter, ride is better and the chassis feels stiffer.

This stuff sounds alot like what the OE's are doing on higher end car's to keep noise down. Anyway, here are a couple link's to the process, with more links inside them.

http://www.sr20forum.com/general-sr20/95856-foamseal-impression-excellent-stuff.html

http://www.sportcompactcarweb.com/projectcars/0006scc_project_nissan_300zx_part_5/index.html

AaRoN
03-08-2008, 10:30 PM
I've heard about Ford using this stuff and a couple other manufacturers.

Jrgunn5150
03-08-2008, 11:09 PM
I wonder if this is what makes the "quiet steel" in the new F150's?

AaRoN
03-09-2008, 08:53 AM
I wonder if this is what makes the "quiet steel" in the new F150's?


I believe so. I'm pretty sure another manuf. uses it but I can't remember who it was.

Brian95SVT
03-09-2008, 10:07 AM
someone should try this then make a write up for it

Jrgunn5150
03-09-2008, 10:08 AM
1. pull out interior

2. squirt foam in holes in A pillar, B pillar, rocker panels

3. wait

4. trim excess

5. replace interior.

AaRoN
03-09-2008, 10:12 AM
:hammer:

Brian95SVT
03-09-2008, 10:13 AM
Just fillin the holes helps that much?

AaRoN
03-09-2008, 10:14 AM
It's basically just sound deadening.

Jrgunn5150
03-09-2008, 10:19 AM
I have no idea what effect it will have on structural rigidity, they claim an increase of 40%. They make the stuff though, so they are biased.

People who have done it claim they have no more creaks and rattles. That can easily be explained by the foam, nothing is able to squeek or rattle encased in foam.

Now as for the foam itself, it IS called structural foam for a reason, it's often used in building construction, boat's, and lately vehicles.

I don't think it will replace subframes or anything, but personally I am somewhat fanatical about chassis rigidity. Everyday you drive around with subframes, your car is bowing down more and more. I hate it, I intended to do through the floor connectors on my car. I would have been a PITA to pull the old MM full lengths and cage to do it though, so I was putting it off.

AaRoN
03-09-2008, 10:20 AM
It seems as if it would add quite a bit of rigidity. Even if it is just "foam".

Jrgunn5150
03-09-2008, 10:23 AM
Well, take it from a guy that knows how to blow up building's, lol. The foam does work well in that enviroment for sure. I certainly don't think it would hurt at all. I mean worst case, it does nothing for rigidity (doubtful, I don't believe 40%, but 0 is unlikely), add's 10 lb's to your car, and makes it quiter.

AaRoN
03-09-2008, 10:28 AM
It definitely has to help with some flex.

94darkhorse
03-09-2008, 11:31 AM
Interesting stuff.

SRT Handz
03-09-2008, 12:47 PM
i can see how that would help with flex that much..just sound detaining.

my buddies in to Car Audio fill parts of the car with foam and i didnt notice any handling difference

realitygt
03-09-2008, 02:17 PM
I don't think it will replace subframes or anything, but personally I am somewhat fanatical about chassis rigidity. Everyday you drive around with subframes, your car is bowing down more and more. I hate it, I intended to do through the floor connectors on my car. I would have been a PITA to pull the old MM full lengths and cage to do it though, so I was putting it off.


your car is bowing because you have subframes?

scarface
03-09-2008, 02:26 PM
I think he meant withOUT

realitygt
03-09-2008, 03:08 PM
I think he meant withOUT


your car still isn't going to bow just because it doesn't have subframes. there have been hundreds of thousands of cars manufactured with a unibody structure and only front subframe and rear frame rails and none of them have "bowing". The thing that can happen is it can twist ur body if you go crazy and do wheelstands and stuff :hammer:

Goldmember
03-09-2008, 05:48 PM
Ford's "Quiet Steel" is basically a sandwich of steel, rubber, and more steel.

Foam making a stiffer chassis? I'm only speculating that it feels that way because of all the noise and whatnot being muted- kind of like the illusion of a stiffer chassis- but maybe the stuff really works. Someone ought to do a before and after on this.

Jrgunn5150
03-09-2008, 06:29 PM
I think he meant withOUT


your car still isn't going to bow just because it doesn't have subframes. there have been hundreds of thousands of cars manufactured with a unibody structure and only front subframe and rear frame rails and none of them have "bowing". The thing that can happen is it can twist ur body if you go crazy and do wheelstands and stuff :hammer:


Sorry bud, look around and see how well doors are opening.

Dairy King
03-13-2008, 09:57 PM
Chevy is doing the quiet steel stuff, too. Atleast on the Equinox. Its two pieces of steel with either rubber or some kind of cloth in between. My science teach in high school bought one, and they gave a sample square of it. It was neat, there was no vibration or sound if you hit it with anything, no matter how you held it.

vermilion
03-15-2008, 10:58 AM
innovative.