Foam shit in sills

[Dogs Danglies]

jamiemirror Wrote:FYI: Infinity (Nissan USA) uses PU foam in some production vehicles.
I think up to 40% stiffness when using "light" PU foam is not so bad.

I might have a search round the internet, see if I can find the stuff Nissan use, would feel better about using something like that if a manufaturer uses it aswell.

My car is having a roll cage anyway, but just wondering more ways to strengthen it

[Sanity Clause]

Quote:
I might have a search round the internet, see if I can find the stuff Nissan use, would feel better about using something like that if a manufaturer uses it aswell.

My car is having a roll cage anyway, but just wondering more ways to strengthen it

The shell needs to flex a certain amount.

It depends on what you intend doing with your car, of course. But I'd suggest that you don't want to make it too stiff, otherwise you could start getting cracks appearing, in places like at the bottom on the screen pillars.

Having said that, you'd probably have to be driving on some pretty rough roads for a while for that to happen.

Seam welding the chassis will help to strengthen and stiffen, but don't weld continously. Leave gaps. Weld 2 to 3cm, then leave a 2 to 3cm gap, and so on.

Double-skinning the sills will also help a little.

A lot of effort for a small gain, though. A properly fitted roll cage will provide most of the stiffness you require.

[Dogs Danglies]

The chassis is going to be drifted (is that a word?) so I want it quite stiff, and dont really want to use it too much on crappy london roads that will pound the shit out of the chassis.

Its been half seam welded when I bought the car so may aswell finish it.

[Tofu @ AE86]

i have a vcd from Best motoring that features this issue, they apply it in one of the presenter´s car, a Skyline, but first, to prove that that Polyurethane foam is stiff like hell, they pour it trough a plastic tube, that, when the foam harden´s (just a couple of second´s) they remove tha plastic tube, leaving a baseball bat shape "foam"....they hammer it agaisnt the floor, that shit is really hard, like wood
but, virtually without any weight....

a couple years ago, i´ve talked with MotoP (from club4ag) about this, because he applied it on is 86, he said that it´s hard to apply because we have to join two separate liquids (reactor & other) and after that, the foam stiffen´s very very fast, it´s sticky like hell....his words, not mine...

one of the products...
http://pagebank.sun-inet.or.jp/~bellco/essh.htm

a review...
http://www.miata.net/products/chassis/bellco.html

other reviews...
http://www.mx6.com/forums/showthread.php?t=129858

[Tofu @ AE86]

"Bellco Power Urethane comes as a 2-liquid compound mix type, in which fluids A and B are mixed in equal amounts, which produce a chemical reaction when mixed together, resulting in a substance that is extremely lightweight and high-strength. Unit price when sold in Japan:"

"Even if the fluid injection and formation process goes wrong for some reason, it will not have a negative effect on the car body strength. However, there is no product available which can dissolve the foam once it is in place inside the side sill.

Because Bellco Power Urethane is a petroleum-based product, it does ignite at 320 degrees Celsius.

Because of the flammability of the product at this temperature, once it is in place inside the side sill it is no longer possible to carry out any direct welding operations on the side sill portion. [u:5f2c155c89]In the event of an accident resulting in major damage to this area, the entire side sill will have to be replaced."[/u:5f2c155c89]

ouch!, too much assle, i don´t know if i risk it

[Dogs Danglies]

Nice one Tofu, I will read through those links, seem to be some good info on there. Wouldnt like to be the poor welder that tries welding up a chassis on a 'foamed' car only for it to go up in smoke

[PazzaAE86]

Most of that foam is flammable. Its bad to put it in a car that is gonna need welding.. AE86's need welding