Chassis strengthening

[Muzz]

awsome! if you havnt already, check out the 1st link in post #75, i like the idea this guy has of driling down a little to reach the second layer of metal, then welding it up, otherwise, unless ur using a high powered welder, u may not be actually fusing the layers of metal together properly. Also doing this would let u use less heat/power which i recon would give less chance of warpage problems.

[Muzz]

read post number 14 in the thread i recomended above ^

[claymore]

If you are going to do it that is good advice. Go to your local parts or tool place and they have a tool that goes into your drill and looks like a mini hole saw about 5mm wide with replaceable "Saws". Body shops use them to drill out the stock robot welds when replacing a panel and they drill out only the first panel leaving a nice small hole showing the second panel underneath so you can weld directly to BOTH panels at the same time. If you can't find some maybe "Skinnyboy" can tell you where he gets his.

To use them if you get good at it you just pick your spot and drill, if you need some practice center punch the spot first then drill. You will feel the drill spin freely when you get through the first panel and a small circle of metal will fall out, BUT you can drill through the second panel if you keep the drill pressure on so stop when you get through the first panel. They are cheap and easy to use so you could drill the holes and your buddies doing the welding can follow you around saving you some time.

[nd55]

Just wanted to correct an earlier post.

Foam used to fill chassis spaces isn't the generic stuff you purchase at the hardware store.

It's two part (like epoxy) and has to be mixed together, then introduced into the void somehow before it starts to set.

Not sure of a local supplier of two part foam.... anyone?

Nick.

[spetz]

There were some posts on ozhonda with links to where to buy this stuff from

I realise it isn't your generic expanding foam stuff. But does this actually help much?

[Muzz]

http://www.sportcompactcarweb.com/pr..._300zx_part_5/ About 2/3 of the way down in this article they talk about foam filling the rails.

here is there verdict

We were amazed at how this simple procedure improved the performance of the car. The chassis now almost feels like it has a roll cage. A sloped driveway can be driven up sideways with nary a creak. Even though the Z already has a pretty tight chassis, it feels more solid. The ride has improved and road noise has been reduced noticeably. We bet that the car will be even more responsive to chassis tuning measures in the future. If you are a slalom racer, a road racer, have a lowered car or even just want a smoother ride; foaming is a worthy, easy-to-do modification. Foamseal has foams in densities as high as 10 lbs per square foot if you desire to make things even stiffer.

[spetz]

hmmm seems interesting
Where to buy this stuff?
And is it easy to DIY or should be done by a panel beater?

[Muzz]

couldnt really say there, i have no experiance with automotive foam. search in google or yahoo australia "automotive foam" im sure ull find somthing.

dont know abuot how difficult it would be to diy, but if a panel beater does it, ul have somone to blame if it makes a mess!
Shouldnt be to hard though, drill a few holes in ur chassis rails, and use a funnel to fill the desired amount, i think it doubles in size as it expands, itll say the expansion rate on the pack. Then scrape off any over flow as it comes out & sand any overflow off when completly dry.
Once again i have no idea about this stuff, but it dosnt "sound" to hard, but could get messy.

[Muzz]

Back from the dead, ive been reading that if u foam fill your rails, and they are damaged in an accident, it makes them almost imposible to fix. Making it a not so smart option for a street car. I cant confirm how valid this claim is but a few ppl have mentioned it in various places around the net.

Ive also read, when doing spot welding/seam welding/seam stitching, it is extreemly advisable to do one weld, then move to another part of the car and do another weld, move back and do another weld etc. and keep varying the places u weld. Also to cool each weld using a hair dryer on cold or somthing simular (not water cus it can crack the welds!), before doing the next one, to help reduce the chance of warpage problems.

[STiR]

Very shortly my EG is going in to be seam-welded(excluding engine bay) and have a CAMS approved cage fabricated (weld-in also), then off to to body-shop for inside-out paint-job. We will have the front fenders removed and have some triangular plates welded on (to serve as a fender brace). Should be very interesting.

[Sp00ny]

I did this to my N14 Pulsar, took freakin ages(about 40 hours?) but going up steep angled driveways it lifts the 2 unloaded wheels! Placing the wheel jack at one 'corner' point will also raise 3 wheels and leave diag opp wheel on the ground.

Wouldn't the size/stiffness of the swaybars and length(stroke) of the suspension change that?

As soon as I installed my 22mm Rear swaybar...my car hits 3/2 wheel motions when entering a driveway. Regardless of how stiff your chassis is (to a reasonable extent) the main things that would cause that would be swaybars and stroke...

Swaybars because when force is applied to one wheel greater force is applied to the other resulting in lifting of the wheel. Stroke because if your suspension setup has a small stroke when entering driveways the wheel has only limited space to drop, causing it to "float" in mid-air not so much be "Forced there".

Chassis ridgidity would help this, but wouldnt be the sole cause. If stock our chassis where twisting that much...there would be some serious design flaws.

[STiR]

Just an update on this front, I've got a cage design sorted in Chromoly and there is a possibility the car could be going in next week to start the work. Otherwise, it will be a couple of weeks before they can fit me in. Look forward to seeing the difference a tower to tower bird cage makes :-)