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Any one try foam-filling their chassis?

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From the website:

"Do not--I repeat--do not attempt to use cheap, hardware-store canned foam. This is not the same thing, and if injected into your chassis, will form a gummy mass that won't dry. Foamseal foam is a professional grade foam, which although it is a little unforgiving to cleanup mistakes, has superior mechanical properties and catalytic curing so it will dry even in an enclosed space."

It looks interesting and it's being used in the auto industry already (Acura's Q45). The DSM would benefit from it since it's been creaking and flexing even when brand new.
 
Looks cool. I'd like to look into that someday, as my old 1g could really benefit from it.
 
Sounds like a fun little winter project I could do since everything's out of the car right now anyways.
 
I have an SE-R buddy who did this to his 240sx. He said it made a difference in how the car felt to him, and road noise decreased. He said prep takes about a day, for pulling stuff out, and taping up holes. It will definitely be on my list of things to do.
 
Sounds like it could be a worthwhile investment for autocrossers. Any clue how much this would cost?
 
Yeah, I finally found the company online. $138 shipped for 5 kits, which is how much SCC used to do the 300ZX. Not too bad. I'm going to do some more searching around for people who've done it before I commit to a project like that though.
 
I'm sure there are some types of foam out there that wouldn't cure in an enclosed area. Plus, SCC probably wants to send the business to the company they featured. Any clue what the density rating was on the foam you used?
 
I have heard of foaming the chassis, but I have never seen a decent writeup on it. The scc article is decent and gives the general idea but there are still some things I'm wondering about. The main thing is how much weight this adds. I would like to do this, and I think along with the seam welding and "finishing"(going from a 4 to 10+ point) the cage would make my car amazingly stiff. If anyone has any more information I would love to hear it. I'm not real sure how much it would help considering my car is already alot stiffer than stock, but it can't hurt(as long as it doesnt weigh much). If it does add a considerable amount of stiffness it might be a huge difference. Dsms(imho) are actually pretty flexible stock(as opposed to what a few people have told me).

silv blt: do you have a link to the company?
 
zephyr_8 said:
I have heard of foaming the chassis, but I have never seen a decent writeup on it. The scc article is decent and gives the general idea but there are still some things I'm wondering about. The main thing is how much weight this adds. I would like to do this, and I think along with the seam welding and "finishing"(going from a 4 to 10+ point) the cage would make my car amazingly stiff. If anyone has any more information I would love to hear it. I'm not real sure how much it would help considering my car is already alot stiffer than stock, but it can't hurt(as long as it doesnt weigh much). If it does add a considerable amount of stiffness it might be a huge difference. Dsms(imho) are actually pretty flexible stock(as opposed to what a few people have told me).
Click to expand...

Mine flexes like a sumbitch when I've got it on the floor jack. I'd love to stiffen it up some. Of course an 8 point cage is in the works, but I'm not sure when that'll actually get installed.
 
My car is at least 2 times stiffer than stock. It makes an amazing difference. I can see how stiff it is just jacking it up on a floor jack. Its even more fun on back roads and bumps. I can hit bumps very hard and it just soaks them up, even on gravel/dirt/mud it just is amazing. I am a VERY big fan of anything that adds chassis stiffness, to the point of evenutally putting a full rally-style cage in.(that and being the "seam welding guy" or at least it seems like it to me since i jump on every stiffness discussion and almost always mention it) Really any improvement in stiffness you'll love. Especially if you race/drive the hell out of it.
 
zephyr_8 said:
My car is at least 2 times stiffer than stock. It makes an amazing difference. I can see how stiff it is just jacking it up on a floor jack. Its even more fun on back roads and bumps. I can hit bumps very hard and it just soaks them up, even on gravel/dirt/mud it just is amazing. I am a VERY big fan of anything that adds chassis stiffness, to the point of evenutally putting a full rally-style cage in.(that and being the "seam welding guy" or at least it seems like it to me since i jump on every stiffness discussion and almost always mention it) Really any improvement in stiffness you'll love. Especially if you race/drive the hell out of it.
Click to expand...

So you have any clues as to which exact foam to use and where you put it in the chassis?
 
The stuff only adds about 10 pounds total. It's 2lbs/cubic feet density and each container makes a cubic foot. They used 5 of them on the 300zx. That makes it 10 lbs. If you can actually achieve a 40% increase in rigidity like they claim with only 10lbs of foam for around $100, it sounds like a great idea to me.
 
Not all foams are created equal, and generally quietness comes from stiffening "drums" rather than stiffening significant structure.

1. Foam can reduce squeaks/rattles by preventing you from hearing them. Ear plugs are a fine example. foaming a body will reduce "airborne" noise from trasmitting into the passenger compartment.

2. Our structures are unibody welded steel. If you can deflect something with your hand/arm-strength. It will not stiffen support for your wheel/tire/suspension.

3. It is relatively easy to stiffen a body panel (drum head) with foam... thus reducing NVH.

4. Significantly stiffening body-torsion or chassis-attachment-mobility requires steel, carbon fiber, or foamed epoxy (modulus of elasticity). Of course, if any of these are added in non-critical areas, weight is the only thing being increased.

5. Mastic, foam, caulking, constrained layer, goop, and the like can easily reduce noise transmitted to the drivers ear.

6. T.V. shows, magazines, and the like are great places for aftermarket suppliers to market their product. Do they care about your lap times or driving feel? no. Automotive aftermarket is fueled by selling parts. Not fixing problems.

7. Stiffening structure can be challenging. 2" Steel tubing routed direct (no bends) between force application "nodes" is generally your best bet.
 
bjones18, So is the stuff these guys are talking about the "foamed epoxy"? It sounds like it to me. Also what is it that we should look and not look for when we go to find this stuff? And where would be the best areas that we should apply this stuuf to our car? i.e. A-pillar, inside of the door sill the the guy in the 240 mentioned in the the link. I'm very curious about this stuff and would likely try it as I autocross and am starting to get into road racing and a stiff chassis would be extremely beneficial.
 
Zero Bar said:
bjones18, So is the stuff these guys are talking about the "foamed epoxy"? It sounds like it to me. Also what is it that we should look and not look for when we go to find this stuff? And where would be the best areas that we should apply this stuuf to our car? i.e. A-pillar, inside of the door sill the the guy in the 240 mentioned in the the link. I'm very curious about this stuff and would likely try it as I autocross and am starting to get into road racing and a stiff chassis would be extremely beneficial.
Click to expand...

I am not sure what they are using. The absolute best place for glue is impossible for us to acheive. Before spot-welding the hem-flanges (and all other structural flange welds) epoxy should be layed between the flanges, then spot-welded through (very messy, as weld expulsions often squirt epoxy out). The epoxy would then cure in the e-coat oven. This makes for a very rigid, durable, and corrosion proof structure. Trying to do this after the BIW is welded together would give questionable results. Those who have tested structural adhesives realize that surface preperation is extremely important.

Personally I would not look to glue or foam to stiffen my body/chassis unless I were using laminated composite panels (balsa, or aluminum/nomex core). However, I would use glue/foam/etc if I wanted to reduce noise in the passenger compartment.

To stiffen a body/chassis I would weld in tubular structure. You care about lateral stiffness and torsional rigidity. Hatch-back cars do not have a package tray (structure between rear shock towers that holds speakers). A roll cage which is properly tied into the unibody structure is best.

by the way, I just got an ebay strut tower bar. It has bends to get over top of the engine (which I will be straightening real quick before I install it). I was able to deflected it with 10-20lbs of force :notgood:

If anyone thinks a rubber band attached between shock towers does anything.... They should mount a HUGE rear airfoil on the rear of their FWD car... most certainly on a deck lid which is supported by rubber weather stripping :D
 
Bjones, in spite of your reservations, I'm sure someone here will try it. Can you recommend a way to objectively test the results? Something that could measure frame-flex before and after?
 
The supplier should provide data if he wants to sell his product.

Otherwise:
Ground out three corners of your body structure solid to ground (with chains), say LR, RR, LF. (dial indicators at these 3 corners will indicate how effective your ground-out is).

The fourth, free corner is for adding/subtracting weight and recording vertical displacement. A weight scale for measuring vertical force and dial indicator for vertical displacement. A body shop frame straightening machine would be a great tool to lock down 3 of the 4 corners. Wheel force scale, dial indicator(s) and many 25lb sandbags to measure force & displacement of the "free corner."

Keep in mind, Fred Flintstone will NOT be able to reproduce or repeat his results. You are looking for millemeters of displacement with 10-20,000 Newtons of Force applied.

The real way to measure uses a laser, targets, hundreds of measurements, extremely complicated set-up, and mathmatical transforms on the data :boring:
 
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