Foaming the chassis

[The Necessary]

F,

unless you knew what you're talking about, you really shouldn't have posted your silly opinions.

But, I guess you must have *thought* you knew something about this topic, hence your post... *sigh*, if only we could all be as blissful and secure in our ignorance and stupidity as you are... Life, would be good.

How's this for an original The Necessary proverb;

"Read why I've posted, throughly, and think about it, else you be the fool that will never be educated".

That's you, F.

Please don't reply to this, for it would cause me (and every other reader) much cranial discomfort to read another of your idiotic, nonsensical replies.

 

[jarance]

Aiyaa, name calling again.. let keep to topic at hand.
It would be interesting to hear from an expert.. So far,we only hear from users only.. any expert care to comment..

 

[E34EuroTouring]

Its actually getting more factual after all the flaming that has been done etc.

Yes, a stiffer chassis will always take a toll on the suspension. But then, hard driving people already knew this. Thats why, their suspension have already be upgrade to BETTER than stock. Mine you, a normal production car, has a lot of compromises for economic reasons. The modder's first job is to identify what those are and how much the upgraded parts will deliver (heck, most sensible modders do, anyway).

Its so easy say, just "throw money at the problem", without really wanting to know what that gives. But a true driving enthusiast wants to know and be well informed about this. Thats why really great drivers know their engine and chassis very well and when a small thing is out of place, they know within 15 mins of driving. This is one reason why so many racing drivers said" Driver and car are one when its moving at the limit". The car becomes an extension of our senses , so we can "feel" the difference.

Those who are into high-end audio know this fair well too. Principle is similar.

Forming is a cheap way of give us what the manufacturer will do in the next model, except for structural changes in suspension. Like the current E90 which has a great 1-series derived rear suspension linkage that is way better than the E46 multi-link geometry.

 

[ALBundy]

Would a car handle better is the chassis is stiffen? Answer is yes and no. It all depends on how you like the car to behave. A stiffened chassis would have less traction and generally will induce more oversteer into your car. Does a car that oversteers handle better than a neutral one?

 

[Redd]

in terms of handling - nothing at all to do with foaming or suspension wear & tear here - a stiffer chassis is almost always better than a less stiff one.

here's why. a stiff chassis has less play and is less sloppy. yes, it might have less overall grip under certain conditions, and/or introduce oversteer.

but u can tune suspension to take care of grip and over/understeer. u cannot tune suspension to take care of sloppiness. sloppiness is sloppiness. ive sat in older cars with chassis made of jello (or u'd think it was) and when ur hooning it, the 4 corners of the car feels like they're doing different things. there's no cohesiveness, no predictability. it's sloppy.

so a good tuner/driver will know that a stiffer chassis is less forgiving and tune the suspension or drive around it.

redd

 

[E34EuroTouring]

Redd,

Well put. Slopiness.. I like it!. Generally, we made a lot of assumptions when doing one thing. Optimization for racing is different from street driving depending on the person's preference. Yeah, if you give race drivers a choice, they would replace the shocks with a solid rod with no suspension at all and let the tires do all the work!. Thats, what I was told by a Formula 3 driver. Super stiff suspension that had almost no travel. The amount of shake is just increadible so it was very very tiring to do 10 laps!.

All things being equal, assuming the suspension components and tires are not the weak point but the chassis is, then, its better handling for sure. Every new model , we hear from manufacturers 30% or 45% stiffer chassis. Must be good right ?. Mostly so, but a lot of the time the dependent suspension parts and tires themselves changed to accomodate the additional load taken by the chassis.

 

[DChong]

Hi guys,

I am Desmond Chong from K L AUTO, the distributor for AUTOFOAM chassis stiffening & soundproofing foam.

It is great to see so much interest & controversy on our humble product. My sincere appreciation to Lee for starting this great thread.

AUTOFOAM is sourced from Europe from a major OEM supplier. It is a Closed cell structural foam specially formulated for AUTOMOTIVE use meaning it is designed to cure consistently & uniformingly in an enclosed space ie chassis. This is very important to ensure there are NO air pockets or voids in the chassis . It is non-hygroscopic--will not absorb or trap water. It is non combustible. In short, it rocks!

Foaming a car is a permanent 1 time treatment.....trust me, we have tried removing the damn thing. It is IRREVERSIBLE. So getting it done RIGHT the first time is paramount.

As to the topic of crash worthiness, below are some technical specs for the techies to chew on.....
Density.........................................23 to 25 kg/cbm
Tensile strength (DIN53455)........18N/ccm
Shear Srength (DIN53455)........ 8N/sq. cm

As you can see, AUTOFOAM is rigid not solid. It reinforces chassis structures but not to the point that the car is cast in concrete.. In Europe, US, Japan, automotive foam is used on crash repair cars to reinforce the weakened structures.The same formulation is used by major car companies in certain chassis joints and on the latest Alfas in the rear chassis to CUSHION shock & impact in the event of an accident.

Internationally prepared Rally cars are extensively foamed. Japs foamed their Drift cars in every concievable orifice.....(.learning from Lee.)

The areas we apply to would depend on the needs and requirements of the client. If one feels that foaming certain areas would compromise the crumple zone ,then omit it. But foaming B pillar & Side sills definitely improves cars integrity and safety.

Car modification is a very personal thing. Some people would even go to the extent of putting Porsche brakes on a Airtrek. Some want their car to handle like a Go Kart.....go full works... AUTOFOAM, H&R, BILSTEIN,RACING DYNAMICS,AC SCHNITZER. ..Want comfort, go for AUTOFOAM cabin......from only rm 680 ...very affordable. So the moral, to each his own.

But one thing is very clear.....AUTOFOAM works!

BTW, the NECESSARY, the failed suspension on our mutual friends car was due to a over torqued rear strut bar.....they over tightened the top bolts.


If anybody needs any more info,give us a call, u can PM me for the number or refer to the first page.

Cheers,

Des

 

[JeffHo]

Can you elaborate on the AUTOFOAM cabin .......


Jeff

 

[ichiwan2]

Autofoam website:

http://www.autofoam.com.my

 

[Redd]

sorry to rehash an old (and possibly sensitive) topic, but i thot the info was worth passing on.

the following info was recently posted at the italiaauto.com forum. the author crash tests cars for a living (the engineering team, not in the car ) so his info is reliable.

the full thread is here:

http://www.italiaauto.com/forum/viewtopic.php?t=4944

but the short of it is this:

Twin_Sparx :-
Ok, if its done at the factory, then MAYBE its ok...cant say for sure.

I've had experience working with stuffing foam (similar to Autofoam) into the A and B pillars when we were trying to improve the crashworthiness of a certain vehicle .

What I found was, if not done properly, not only did it clog up hidden drainage holes (as expected), it varied the cross sectional stiffness very unpredictably.

In the A-pillar, just lining the inner cavity of the pillar inner and outer reinforcements made it almost 50% stiffer. Good? Lets say I spent about 6 months running simulations to optimise the size of the foam block inside the cavity to enhance the structural stiffness and provide the proper 'folding mechanism' of the pillar upon impact.

Its even worse in the B-pillar and side sill. Most B-pillars have a hinge location where the pillar is designed to buckle when T-boned. The sill is also allowed to fold upon itself...ie, outer crushes into inner sill.

You'd be surprised.... it may seem like not a big deal when you look at how soft the foam is, but stuffing A & B-pillars and sills with it will alter the crashworthiness of your vehicle quite significantly. So, instead of folding up and crushing systematically as designed by Alfa crashworthiness team, you're in better chance of getting it randomly mangled.

so good luck autofoaming ur car.

redd

 

[The Necessary]

That's some great info, Redd. When it comes to topics where safety is concerned, there shouldn't be any 'expiry date' to sharing new, and potentially important information.

 

[E46Fanatic]

For once.. the Necc is right... *clap* *clap*

Twin Spark is right, manufacturers spend a lot of time and effort in simulating and testing for crash worthyness in their new cars... Don't try to be too smart by altering the dynamics of what they have designed in the first place, esp. when it comes to safety issues.

A screen shot of LS-Dyna (which is used for crash test simulation, failure analysis, large deformation dynamics and contact etc) taken from a collegue's computer . Its real science..

 

[The Necessary]

And not for the first time, e46f has had to eat humble pie... Muahahahaha!

 

[DanPromote]

Interesting, in summary Autofoam works but be careful when foaming your car, so that it does not affect the crumple zones.

 

[Lee36328]

Originally posted by Redd@Feb 13 2006, 11:35 AM
sorry to rehash an old (and possibly sensitive) topic, but i thot the info was worth passing on.

the following info was recently posted at the italiaauto.com forum. the author crash tests cars for a living (the engineering team, not in the car ) so his info is reliable.

the full thread is here:

http://www.italiaauto.com/forum/viewtopic.php?t=4944

but the short of it is this:

Twin_Sparx :-
Ok, if its done at the factory, then MAYBE its ok...cant say for sure.

I've had experience working with stuffing foam (similar to Autofoam) into the A and B pillars when we were trying to improve the crashworthiness of a certain vehicle .

What I found was, if not done properly, not only did it clog up hidden drainage holes (as expected), it varied the cross sectional stiffness very unpredictably.

In the A-pillar, just lining the inner cavity of the pillar inner and outer reinforcements made it almost 50% stiffer. Good? Lets say I spent about 6 months running simulations to optimise the size of the foam block inside the cavity to enhance the structural stiffness and provide the proper 'folding mechanism' of the pillar upon impact.

Its even worse in the B-pillar and side sill. Most B-pillars have a hinge location where the pillar is designed to buckle when T-boned. The sill is also allowed to fold upon itself...ie, outer crushes into inner sill.

You'd be surprised.... it may seem like not a big deal when you look at how soft the foam is, but stuffing A & B-pillars and sills with it will alter the crashworthiness of your vehicle quite significantly. So, instead of folding up and crushing systematically as designed by Alfa crashworthiness team, you're in better chance of getting it randomly mangled.

so good luck autofoaming ur car.

redd

Redd,

I have read your postings in italiauto, and in autoworld.

Was not going to comment until you said you made your postings here and have not been crucified. Rather than spoil your record, and imply silence is consent/agreement, my opinions and comments below.

If twinsparx has a point to make, let him make it here. If he has evidence, let him show it. So far, it has been on a basis of : "Trust me, I'm an engineer, I make a living crashing cars, and I've got tons of evidence, just can't share it with you because it's manufacturer's secrets. Take my word for it, stay away from foaming."

Unlike the other postings, we are (hopefully) all logical and mature people here. So, let's hope the discussion will be kept logical and non-personal; none of the name-calling in the other forums please.

I am intellectually and genuinely curious what twinsparx has found out in his research, and what evidence he has for backing it up. [And no, stuntmen w bats don't count. ] I'm ok w his explanation, up to and including saying that foaming will alter the crash dynamics in unpredictable ways. Agreed. That sounds logical so far. To make the leap from there to : foaming is dangerous, do at your own peril; seems like a generalisation to me, unless there is evidence that foaming, specifically the sort done by Autofoam, is proven dangerous.

Why Autofoam? Why was Twinsparx's views linked to it? Unless his study includes how Autofoam is done by KLAuto, and concludes the KLAuto foaming techniques are wrong/defective, I find these insinuations that Autofoaming by KLAuto is improperly done and therefore dangerous, as opposed to foaming done by the manufacturer, libellously unsubstantiated.

Granted, I also do not have evidence that the foaming done by KLAuto is NOT defective and NOT dangerous, so I reframe from making any claims, positive or negative. Like you said, buyer beware. I have, however, taken many corners before and after foaming, and can testify to its benefits in that context.

Whew! Did not mean to ramble for so long! B)

 

[fabianyee]

No doubt the effects can be felt as far as foaming is concerned, especially at the corners and oso sound dampening.

The other issue is how it affect structural deformation in the event of a collision..

I'm not against or for in this matter.. just pointing out the 2 perspectives which are being disccussed.

 

[E46Fanatic]

Cold hard evidence in this area will be impossible to post in a forum like this.. both from a feasibility point of view as well as confidentiality considerations from the company he works for.

But I am sure if you are keen enough you can get in touch with him or pay him a visit to see the simulations .

I have seen data and models on crash analysis for automobiles, and every part of the structure of the car has properties which are part of the model. The behaviour and dynamics of deformation is a factor of all these individual properties to give you the outcome you would want in the case of a simulated impact. Thats why the use of high performance computing and advanced simulation software is used for the element analysis by most if not all modern car manufacturers. Change parts of that model, and the outcome will differ. When parts are meant to disperse and absorb the forces do not play its role other parts of the model will behave differently and as what Twin Spark mention, the likelyhood of achieving an adhoc mangled wreck is probably what you'll get instead.

How do you prove this? Well its all in the simulation and models.... You'll need software, hardware, models and the expertise to get your proof.

 

[Lee36328]

Originally posted by E46Fanatic@Feb 14 2006, 09:10 AM
Cold hard evidence in this area will be impossible to post in a forum like this.. both from a feasibility point of view as well as confidentiality considerations from the company he works for.

But I am sure if you are keen enough you can get in touch with him or pay him a visit to see the simulations .

I have seen data and models on crash analysis for automobiles, and every part of the structure of the car has properties which are part of the model. The behaviour and dynamics of deformation is a factor of all these individual properties to give you the outcome you would want in the case of a simulated impact. Thats why the use of high performance computing and advanced simulation software is used for the element analysis by most if not all modern car manufacturers. Change parts of that model, and the outcome will differ. When parts are meant to disperse and absorb the forces do not play its role other parts of the model will behave differently and as what Twin Spark mention, the likelyhood of achieving an adhoc mangled wreck is probably what you'll get instead.

How do you prove this? Well its all in the simulation and models.... You'll need software, hardware, models and the expertise to get your proof.

"Cold hard evidence would be impossible to post...", well, that makes my point, until there is evidence, it is all conjecture isn't it? I am a doctor, so take this medicine without questioning me? I am engineer so take my opinion without question?

"...When parts are meant to disperse and absorb the forces do not play its role other parts of the model will behave differently and as what Twin Spark mention, the likelyhood of achieving an adhoc mangled wreck is probably what you'll get instead." - I was in agreement w this para, until the "adhoc mangled wreck" part, which does not sound very technical and scientific. You mean, "the model will crumple outside the manufacturer's specification." don't you? In either case, they all crumple, and if you like, becomes a mangled wreck. The question is, whether it crumples as designed or not.

 

[The Necessary]

Lee,

wow, no need to get so partisan here!

If you had actually read what was posted on italiaauto, you would have realised that it was "musclehedz" who first mentioned "autofoam", and then "twin_sparx" warned everyone agaisnt it based on his experiences/knowledge.

IF like you say; "twin_sparx" is saying; "Trust me, I'm an engineer, I make a living crashing cars, and I've got tons of evidence, just can't share it with you because it's manufacturer's secrets. Take my word for it, stay away from foaming." (which, btw, he's not. but if that's how you read it...), then what is your post? "Trust me, I'm a good friend of the guy who does Autofoam, I'm not an engineer, I've no empirical evidence, BUT I've taken alot of corners, so I know."?

I think Redd had the best of intentions when he posted that information. And him not getting "crucified", as you put it, is because the vast majority of us here agree with him. I'm glad you're sharing your point of view, but unfortunately, it seems that your information is less reliable than Redd (or twin_sparx's) and is more concerned with defending the brand (Autofoam) than the relative merits/demerits of foaming.

 

[The Necessary]

Originally posted by Lee36328@Feb 13 2006, 08:42 PM
The question is, whether it crumples as designed or not.

Wait a sec... how do you think cars are designed to crumble/crumple? Ummm... with maximum regard to the safety of the passengers inside (and these days, outside), I would hope! Don't you agree, Lee?

SO... if it doesn't crumple as designed... hmmm... which you agree that foaming does contribute to... I wonder... does it mean it will crumple better or worse?

Well, we can't determine "better" or "worse" arguing on the internet now, can we? But we can definitely agree that it won't crumple as designed. And if it was designed in the first place for maximum survivalbility, not crumpling as designed would lead to... (you fill in the blank, Lee).