Chassis strengthening

**claymore** · 14-11-2006 12:08 AM

i know its bad with welded in cages, when mounting the plates to the car, the good cage builders will do in weld inch then no weld then inch weld to keep some strength in the area, cus it can punch through easier if welded all around the plate.

This is not quite true. They do weld a bit then a bit more to prevent warping because the metal gets too hot to do it all at once and to get the parts aligned then they go back and finish the weld. You really need to weld all the way around roll cage parts even the brackets it's MANDATORY in most racing sanctioning bodies and they do inspect it before certifying the roll cage.

If you want to see an example of spot welding look in the photo above, look along the floor on the extreme left side where it meets the body, all those little black spots running up the inner wheel well are spot welds.

**Muzz** · 14-11-2006 12:22 AM

i like this thread

learning lots here.

**Muzz** · 14-11-2006 12:45 AM

take a look at this spetz - good info here especially down the bottom of the page- http://www.drifting.com/forums/showthread.php?t=1097 obviously this guy has had experiance with it before.
also for good pics - http://www.shockdrifting.com/articles/view.php?id=49

**Muzz** · 14-11-2006 12:48 AM

Originally Posted by claymore

Seam welding means you weld along the seam entirely (weld the whole seam).
Spot welding is where you weld in one spot for about an inch then move along the seam and do another small weld leaving parts of the total seam not welded so the welds look like dots along the seam not totally one long weld connected together.

ive been looking around the net for quite a while trying to learn a little more on the subject, and it seems no one uses a continuous weld along the seams, so far ive only seen spot welds and stitching type welds.

**claymore** · 14-11-2006 02:01 AM

Yep not positive on the reason but most professional race teams only use spot welding in the body seams they do not weld the whole seam.

**iamhappy46** · 14-11-2006 08:10 PM

Originally Posted by iamhappy46

Solid normally stops the car from deforming in an accident, which means the occupants normally take all of the stored energy from an accident. This normally means fatalities and is why crumple zones/safety cells are created in modern cars.

Reason why nobody welds all the seams. It also means that the ENTIRE chassis deforms in an acident as the impact energy stresses the entire car. A small bump in the front left hand corner could break welds in the rear right hand corner and warp the entire car, making future wheel alignments a nightmare

Basically, anything that is part of the roll cage is welded tight. Anything else(usually front strut towers forward) is normally tack welded on for easy replacement after a collision.

**ekslut** · 15-11-2006 11:49 AM

So would semi-seam welding or spot welding be the best option for a dedicated track car? I am about to get my car re-sprayed, so I have been thinking about getting something along these lines done.

Does anyone know of any good advice/links on how these welds should be done?

**claymore** · 15-11-2006 05:24 PM

From my research into pro racing teams it looks like they do a weld of about 1/2 inch (little bit over 1cm) move along the seam about 6 inches (15cm) and do another 1/2 inch then keep repeating the process along the seam. With most of the trim in you can only get to the exposed seams on the underside but if it's a track car with stripped interior then there are loads along the wheel wells and floor boards that you can do. But look out as it's a long process so it might be pricey if you have a shop do it. And with any welding be very careful of FIRE and be sure to disconnect your battery and if you have the time take the alternator and ECU right off the car to prevent any possible damage from the welding.

**Muzz** · 15-11-2006 05:26 PM

**iamhappy46** · 15-11-2006 06:02 PM

ekslut: Semi seam welding is the best option. Front and rear strut towers, then everything in between is the best parts to weld, although the ED Civic could do with some strength around the radiator support as well, as the castor rod attaches there.

One inch long weld with say between a 2"~4" gap between welds will make it strong enough as your car is probably very light.

Best thing is, when you go up driveways at an angle, you can actually feel the whole chassis staying stiff instead of twisting. I will get pics of my N14 Pulsar interior shortly.

**Muzz** · 15-11-2006 09:59 PM

sweet id luv to check out ur pics too

**ekslut** · 16-11-2006 08:11 AM

sweet, thanks for the advice guys.

The car is already completely stripped, all sound deadening removed, etc...
I have a few mates who can weld, so I think I will just get them to do the job

So basically if I got a 1/2" - 1" weld every 4" that would be all good?

Originally Posted by Muzz

sweet id luv to check out ur pics too

I'll post up some pics when its all done