| Author | Topic |
|---|
Location:
W.A
Registered:
May 2004
|
 Frame strengthening with foam!
|
Thu, 13 May 2004 07:07
|
 |
Recently I read two articles from club4ag which contained using polyurethane expansion foam to strengthen the body of the AE86.
Here's a bit from one:
".. The second step in structural reinforcement involves the use of expansion polyurethane to fill doorsills and rocker panels. The 2 part, high-density mix is used to solidify hollow areas of the mid-chassis and cabin floor pan. It has been tested to increase torsional rigidity of the AE86 3 door by 45% percent as opposed to 11% by 6 point roll cage .."
Link to full article:
http://www.club4ag.com/faq%20and%20tech_pages/Moto -P's%20New%20AE86%20Part%201.html
And used in a racing levin in all frame structures:
http://www.club4ag.com/faq%20and%20tech_pages/IIda %20AE86%20project.htm
Has anyone ever heard of this or done this?
If so where can I get this stuff, is it easy to use, and about how much does it cost?
I'm just starting an ae86 project, and since im going to strip everything, was just wondering if it's worth doing...
Car will be mainly used for street driving, maybe motokhanas drifting and the odd drag! 
|
|
|
Location:
1st street on the right
Registered:
November 2002
|
|
|
Location:
Adelaide, SA
Registered:
May 2002
|
|
Re: Frame strengthening with foam!
|
Thu, 13 May 2004 07:32
|
|
Its a part polyurethane foam - you can get it from some refridgeration suppliers as it is used as insulation in fridges etc.
Essentially you'd mix part A with Part B, pour it in the sills and as it cures it exapnds. Any moisture in your sills will remain there (until it rusts through), and because the foam is quite absorbant you need to make sure that no water will get into the sills.
It's been mooted a couple of times before but I'm not sure if anyone has done it yet.
|
|
|
Location:
Northwestern Sydney
Registered:
August 2002
|
|
Re: Frame strengthening with foam!
|
Thu, 13 May 2004 07:34
|
|
I've looked in to this but not for structural rigidity. More along the lines of sound proofing.
It's interesting that it can provide additional strength.
I admit now that I havn't read the articles but the first thing that springs to mind is what happens if water gets in there? It seems that you would have to at least fish oil the areas to be applyed before using it if you were concerned about the body lasting. in a racing application the long term prospects of the vehicle aren't too bright as they tend to be damaged/repaied/written off often. On a street car My concern would be if water were to get in to the void it really has nowhere to go but sit there and rust.
the 2 part product can be made reasonably cheaply and is quite rigid (like foam but finer)
I was told for less than $90 you can get enough to create a block of about 2m^3 but that I'm unsure about.
Hope this helps, I'll read those articles when I get in tommorrow.
|
|
|
Location:
Northwestern Sydney
Registered:
August 2002
|
|
Re: Frame strengthening with foam!
|
Thu, 13 May 2004 07:35
|
|
Damn beaten to the Punch 
|
|
|
Location:
Eskilstuna, Sweden
Registered:
May 2002
|
|
Re: Frame strengthening with foam!
|
Thu, 13 May 2004 08:43
|
|
| d-shiznit wrote on Thu, 13 May 2004 17:07 |
It has been tested to increase torsional rigidity of the AE86 3 door by 45% percent as opposed to 11% by 6 point roll cage .."
|
I know it is not your quote etc, but that figure of 45% vs 11% just sounds far to good to be true.
I have not heard of foam being used at all in modern rally cars though.
|
|
|
Location:
Madrid - Spain
Registered:
August 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 03:36
|
|
I think everyone is getting a little misled by the above numbers.
Yes it will give an improvement. No it won't stiffen the chassis more than a well designed roll cage. If the cage only stiffened it by 11% then it wasn't a very well designed cage.
It is not surprising that you can get measurable gains from using it, however I find it hard to believe that using this foam alone, they achieved 45%. The least stiff area for torsion in any monocoque car is through the cabin area (where the doors are). You can't get a lot of foam inside the sills and pillars, not enough to make a huge difference in this region anyway. You could however stiffen the areas either sided of this by filling the box areas behind the front wheels and in front of the rear ones. This could give noticeable improvements in stiffness as will seam welding in these areas.
The down-falls with using it though is as mentioned before, possibility of panal damage when the foam is expanding/curing. risk of moisture ingress causing corrosion. And once it has started to corrode, I don't think it would be a great idea to put a welder near it.
This is also a cure for some chassis squeaks too.
|
|
|
Location:
Baulko Hillo
Registered:
April 2004
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 04:11
|
|
I saw a demonstration of them using this stuff on a BEst Motoring or some other Option vid. Looks just like Space Invader, but I'm sure it's more dense than that.
They poured it into a square transparent plastic tube and when it set, it appeared to be very rigid. Then they poured it in some dude's sills. I've also seen guys using it to insulate fuel systems in the back of club cars, but I think that was a bit of an experiment!
|
|
|
Location:
South Australia
Registered:
July 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 06:59
|
|
Yep - a six point roll-cage that doesn't even connect to the strut towers will do next to bugger all for torsional rigidity. Especially given where torsional rigidity is usually tested. (still saves your ass in an accident though)
A proper 10 point roll cage will crap on the foam for torsional rigidity.
*however* that foam is still efficient at strengthening a chassis - but I'd only use it if I had some spare weight and I would try to double up by using it for ballast as well as for torsional rigidity.
|
|
|
I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 07:10
|
|
space invader.
if you look in the factory manuals for the VT commodore you will actually find space invader listed as a part.
the VT uses it for sound deadening in the A and C pillars - quite amazing its listed as a part....
|
|
|
Location:
Melbourne
Registered:
May 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 07:15
|
|
it's used on quite a number of race & rally cars still. you need to use a 2-pac closed cell type or the car will rust out very quickly.
pain to repair a car with this stuff in the sills though!!
quite messy to use& the correct stuff just happens to give of a gass named isocynanide as it's going off!!
T
|
|
|
I supported Toymods
Location:
melbourne.victoria.austra...
Registered:
June 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 07:18
|
|
ooooh isocyanide has to be good for you..... 
|
|
|
Location:
GoldCoast/Brisbane
Registered:
May 2002
|
|
Re: Frame strengthening with foam!
|
Fri, 14 May 2004 10:21
|
|
|
I can see my lips turning blue already!! LOL!
|
|
|
