Chassis stiffening via various methods...
no
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It's always good to be certain when you are messing with stuff like this. Your description gave me a mental picture of a pile of foam chilling at the side of your house.
Off topic: I'll bring those motor mounts by qsl this thursday if you want to take a look at them. I should be putting them in this weekend.
Off topic: I'll bring those motor mounts by qsl this thursday if you want to take a look at them. I should be putting them in this weekend.
buildin' it
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just cuz i'm curious, what kind of weight are we talking about?
i get the whole you can't stiffen a chassis without adding weight to it, but is the foam really that much of a better option than say a roll cage?
just lookin for some opinions
i get the whole you can't stiffen a chassis without adding weight to it, but is the foam really that much of a better option than say a roll cage?
just lookin for some opinions
FORE:sight
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A full cage is for 1) requirements of sanctioning bodies. 2) actual roll-over / crash protection. 3) a place to hang your multi-point belts. 4) impress high school girls with your "race car".
A foamed unibody provides none of these.
If you were to compare a 4-pt bolt-in cage to a foamed (rockers, cross bars, a-b-c pillars) car, the foamed car would be stiffer. A cage really isn't designed for chassis stiffness. If you weld it in and gusset it to other members, then yes you get some stiffening. Most of the cages around here aren't though. Ever get you hand pinched between the a-pillar and a front cage tube? That's the unibody still transferring all the suspension loads while the cage carries none. You're not making anything stiffer without transferring the load through the reinforcement.
So as far as a gussetted cage versus chassis foam, the cage in this comparison would be way stiffer. It would also be way more invasive, way more expensive, and way heavier.
As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
A foamed unibody provides none of these.
If you were to compare a 4-pt bolt-in cage to a foamed (rockers, cross bars, a-b-c pillars) car, the foamed car would be stiffer. A cage really isn't designed for chassis stiffness. If you weld it in and gusset it to other members, then yes you get some stiffening. Most of the cages around here aren't though. Ever get you hand pinched between the a-pillar and a front cage tube? That's the unibody still transferring all the suspension loads while the cage carries none. You're not making anything stiffer without transferring the load through the reinforcement.
So as far as a gussetted cage versus chassis foam, the cage in this comparison would be way stiffer. It would also be way more invasive, way more expensive, and way heavier.
As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
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As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
Formerly IThaJokaI
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I was reading one of the original threads from someone doing this to an S14. He did the a/b pillars, seat rail thingys, rockers and back seat thingys. He said that he used enough foam to be equal to about 20lbs once dry.
I dont know about you, but 20lbs and a shit load more rigid. Im in.
I dont know about you, but 20lbs and a shit load more rigid. Im in.
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buildin' it
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A full cage is for 1) requirements of sanctioning bodies. 2) actual roll-over / crash protection. 3) a place to hang your multi-point belts. 4) impress high school girls with your "race car".
A foamed unibody provides none of these.
If you were to compare a 4-pt bolt-in cage to a foamed (rockers, cross bars, a-b-c pillars) car, the foamed car would be stiffer. A cage really isn't designed for chassis stiffness. If you weld it in and gusset it to other members, then yes you get some stiffening. Most of the cages around here aren't though. Ever get you hand pinched between the a-pillar and a front cage tube? That's the unibody still transferring all the suspension loads while the cage carries none. You're not making anything stiffer without transferring the load through the reinforcement.
So as far as a gussetted cage versus chassis foam, the cage in this comparison would be way stiffer. It would also be way more invasive, way more expensive, and way heavier.
As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
A foamed unibody provides none of these.
If you were to compare a 4-pt bolt-in cage to a foamed (rockers, cross bars, a-b-c pillars) car, the foamed car would be stiffer. A cage really isn't designed for chassis stiffness. If you weld it in and gusset it to other members, then yes you get some stiffening. Most of the cages around here aren't though. Ever get you hand pinched between the a-pillar and a front cage tube? That's the unibody still transferring all the suspension loads while the cage carries none. You're not making anything stiffer without transferring the load through the reinforcement.
So as far as a gussetted cage versus chassis foam, the cage in this comparison would be way stiffer. It would also be way more invasive, way more expensive, and way heavier.
As far as weight, simple 4/6pt cages are (very) generally a couple dozen pounds. This foam I used is 8 pounds / cubic foot. 1 cuft is 957 fl ounces. I put about 180oz of liquid component in to the car, which expanded to about ~400 fl oz worth of space. So I added about 3.5 pounds to the car. I probably need to add 2 more pounds before I finish.
didn't realize that stuff was anywhere that cool...
any write ups/pointers on how to do it "the right way" to get the most out of it?
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