foaming a 240 frame would make the car more prone to fish tailing, same as adding a rear sway bar. foaming the fraim is best on FWD and AWD cars or RWD with close to 50/50 weight dist. . If you stiffen the rear of a 240, your car will fishtail like no tomarrow. it'ed make a nice drift setup. thats about it.

 

Could that not be taken care of with some forethought and planning?

Saying foaming the chassis will make it spin happy could be correct. I'm not arguing that point.

The point I would like to make is this. Yes adding a rear swaybar can disturb your balance. But this is countered with the proper front swaybar.

I can't see a problem with doing the same when foaming.

Plus equal parts foam in a chassis where stiffening points are equal wouldn't just make the 'whole' chassis equally stiff?

If the chassis was 48/52 and you improved 2% front and 2% rear wouldn't that still keep it's ratio 48/52?

Just more food for thought.

I could also see foaming spots where the chassis is weak and could be aimed to induce oversteer or understeer......

What do you think?

-Stanley

 

I can see what you sayin, i think we're b oth right its hard to be definet on this, bassicly gotta use your knowlege of physics torsion etc.. to guess whats gonna happen till you do it.

I'm still gonna asume that stiffining the whole chassie would prob hurt. only reason i think so is , if you reduce flex in the rear, along with performance springs the rear would tend to hop rather then just dissipating the energy threw flex in the rear. The hoping would make it prone to fishtail. Unless you were on a perfectly flat paved road w/o bumps.

 

You do not want to weld the frame! By Splicing the frame you will create a "hardened" area (heat effected zone). This will be stiff and prone to cracking with the flex of the frame even with the foam. Also Anyone who has ever spliced to things together would know how hard it is to keep them perfectly straight. It is almost imposable to weld the frame 100% true no matter how many clamps you put on it.

 

I will be seeing it soon. I am going to stitch weld a AE86 in a couple weeks and it is getting foamed as well.

Hold on. I cannot agree with this at all.

Your car would not hop. Your springs are there to dampen the road imperfections with the help of your shocks.

It is counterproductive to keep a chassis loose as you stiffen your springs. If you make a stiffer chassis you can run a stiffer spring rate to keep the ratio correct.

There are some really good books on this. The first one that comes to mind is "Secrets of a Solo Racer".

Have you guys ran subframe spacers? They are solid metal. You use them to defeat the OEM rubber bushings. Defeating the rubber takes out slop or as you say "flex".

When you get rid of this flex you eliminate wheelhop. When fine tuning a suspesion you want to remove as many "if ands or buts".

Example:

If my rear subframe has a worn rubber bushing and I run my upgraded coilovers I will continue to have wheelhop when the subframe shifts.

Eliminating the shift gets rid of one more if

Hoping would make the car prone to fishtail. I agree with you there. It still would on a perfectly flat road as your wheels would not be making contact.

You are spending good money on coilovers but still leaving a weak spot on your suspension.

Have you guys ran this stuff in your cars yet? I am speaking from experience with the components and chassis I have owned. I don't want to come across as a "know it all" but more of a "oldtimer that has been thru a lot".

-Stanley

 

Why not? You have seams that are made to flex under normal street conditions. A car that is going to see track and is being built for improved performance warrents improved building.

I can see brittle if you do not know what you are doing. Of course as with anything technique and skill are factors that have to be worked with.

That is like saying no one should drink beer because you can die from poisoning.

Technique and moderation governs how drunk you get.

Same with welding.

Of course if it is done incorrectly. But to just say so I would have to disagree.

Here take a look at this dandy:



The pipe's cap.



The pipe cut into coupons.



Coupon after a 18k foot pound pressure bend.



Root was fine.



Cap was fine.

Heat effected zone was kept in check in ratio to the base metal thickness.

So you are right that the HEZ can lead to cracks. That is if the welder doesn't know what he is doing.

A trained welder will know when to move to another spot to keep the HEZ in good condition.

It is not hard if you keep your HEZ in check. If you don't metal likes to fishmouth. Tack, tack, tack and keep the HAZ in check. There are also devices to measure the temperature of the base metal so warping is not done.

It all comes with training. Are you a welder by trade jbask?

Don't want to challenge you but I am a newjack (Welder A in my company) and have plenty of info if you are interested.

We can all have what we want and it will all rock!

I wouldn't put clamps on the frame. It is already together. You are improving on what is already there.

We can all make really good stuff with great quality. It just takes training and an open mind.

Please feel free to argue anything I have posted. I am here to learn as well as share what I know.

-Stanley

 

some good food for thought. I know more then most but there is someone who always knows more, and i'm not stuborn to say you make sence. Something worth trying out.

 

Sounds like a plan. We are close maybe we will hang out at a meet or something?

Need help wrenching on something or you can pass by when we are building the car. Garage is set up and we are waiting on electricity to be ran.

Also here is another one. There is also another mis-information out there. When we all read magazines and see a glimpse of what the pros are running we can lead ourselves down a ****ty road.

Yes so and so might be running 21k fronts and 19k rears. But what has he done to chassis?

There are so many factors it is mind boggling. Right now I am researching a instaspool ka-t setup for my car. Vmount and all that good stuff.

 

sounds like a plan. I'm working on opening my own shop late this yr also , would be nice. Mine is gonna be a servies center but at night the bays are still open hah.

 

I am a gypsy mechanic now. The garage I am talking about is a modular drop off unit for my friend's car.

Good luck with the shop.

Anyone else want to foam a frame? Should be fun!

 

ever wonder why the pro drifters weld areas on their frames??? or why built auto cross cars do the same thing??? chassis stiffining is one of the oldest tricks out there... welds in the right spots can help handeling dramatically... that is why there are things like door braces roll cages (other than roll over protection) sub fram connectors sway bars and strut tower bars... all of these things are designed to stiffin a wobbly house of cards... all are designed to reduce flex in the chassis as well as stiffen up the suspention... frame grafting has been around longer than even i have...

if i were to build a race only car i would reweld almost every spot weld on the car... why... so stiffen up the whole unibody construction... as well as add custom sub frame connectors that are welded in at the body points and welded to the frame... all of this would lead to a lot of road vibration being transfered into the car... that is why the factory does not do this... a car is built as a give and take situation... you give up stiffness to gain quiet road driving... you give up hp for emissions standards... you give up handeling to gain ride comfort...

scratch building a car for race or performance driving you are not worried about these things... weld the hell outta the frame and the body and see what you get...

ps... my 9 second civic was welded front to back and it passed nhra rules and specs on welds and safety...

 

Got any pictures or insite on running/building that civic?

Also any advice is appreciated.