31 replies to this topic

[soycory]

I am planning on painting my 3G this summer... So, while I have it stripped down I thought about doing the foam filled chassis for stiffness.  Has anyone here tried this?  Haven't found a thread on it...

Thanks

[PuddleSkipper]

I don't think this is a good idea but maybe someone else will disagree. I know people that would carve out rust holes, fill it with foam, and bondo over the top and it would never last.............With that being said if there is any moisture in your chassis when you fill it with foam, and there is moisture in the air, if that is sealed in by the foam the only way for it to come out is to rust it's way out. If you wanna strengthen your chassis I would say add a roll bar or weld in some other structural support. If you don't want to weld you can add the strut bars to the front and rear,strut bars, a B pillar bar and a C pillar bar, fender braces, ect..... check out the stuff Chedda is making. Once you decide to do this it would be difficult to undo.

[soycory]

This is the thread I was reviewing:

 

http://www.sr20-foru...ng-chassis.html

 

Supposedly made a huge difference...

 

I understand about the water issue, but if my car has been parked for a long period of time with the interior removed, I don't think that would be an issue. I am interested in the front fender brace cheddaj makes as that seems to be the part of my car that seems to be weakest... Also thinking that the back ind must be like a can with the end cut off since I have a hatch...

[Harvey886]

That's Dumb.

[soycory]

That's Dumb.

Care to elaborate?

[anjin]

I have heard of this being done within the closed sections of the chassis - like the body and engine bay rails and body sill. The idea is that the foam keeps the sides of these sections stabilised and so improves stiffness. As there aren't a lot of sections like that in the body, I can't see there would be a lot of advantage.

I still like the option of taking some of the straman additional stiffening to improve the torsional stiffness of the bodies.

[asianflava]

You'd better hope that no moisture gets trapped in the foam.

[chedda_j]

You know what works better? Speed holes through out all the pillars and adding gussets with more speed holes. Then a DOM roll cage.

[Doodson]

Did this to my racecar,  It never see's the street and very little rain.  Basically foamed the side running board area and a few other small spots 

[soycory]

Did this to my racecar,  It never see's the street and very little rain.  Basically foamed the side running board area and a few other small spots 

could you tell a difference?

[Harvey886]

Care to elaborate?

 

What happens when you leave wet clothes in a washing machine for a week, MOLD! same thing will happen whith spray foam. no air movement and warm moist environments equal mold. Your car will start smelling like a pair of moldy socks especially when humidity is high. If you are going to do it get foam that is mold resitent. You would be better off with chassis stiffeners.

[curtperry]

This is the thread I was reviewing:

 

http://www.sr20-foru...ng-chassis.html

 

Supposedly made a huge difference...

 

I understand about the water issue, but if my car has been parked for a long period of time with the interior removed, I don't think that would be an issue. I am interested in the front fender brace cheddaj makes as that seems to be the part of my car that seems to be weakest... Also thinking that the back ind must be like a can with the end cut off since I have a hatch...

 

I saw that thread a few years back... read the whole thing.  Then i did a lot more research and decided to do it.  I foamed my project 3g civic in dry conditions (in my garage for months prior) and I can tell you without a doubt that it makes the chassis way stiffer.

 

I can't give any feedback about how it feels on the road because it's still on stands in my garage (i have 3 kids and no spare time).  I can, however, share this tidbit: when I was putting it up on the jackstands at all 4 corners after foaming it, one of my jackstands was a notch lower than the other 3 (1/2 inch), and the chassis was teetering above it.

 

If you have any questions let me know.

[soycory]

I saw that thread a few years back... read the whole thing.  Then i did a lot more research and decided to do it.  I foamed my project 3g civic in dry conditions (in my garage for months prior) and I can tell you without a doubt that it makes the chassis way stiffer.

 

I can't give any feedback about how it feels on the road because it's still on stands in my garage (i have 3 kids and no spare time).  I can, however, share this tidbit: when I was putting it up on the jackstands at all 4 corners after foaming it, one of my jackstands was a notch lower than the other 3 (1/2 inch), and the chassis was teetering above it.

 

If you have any questions let me know.

What did you fill?  Frame rails?  

[curtperry]

Here is where the structural 8lb/cu.ft. foam went:

 

 

 

 

[soycory]

THAT is awesome! That is exactly what I want to do. Looks like it could really help. Your pictures are great. Thanks