I'm race prepping my AP1 for time attack racing. I have been a welder/fabricator for several and do all of the fab work myself. Now that I have the stripping complete and it's time to start re-building I have run into a dilemma.

I am very familiar with stitch welding a chassis and the positives/negatives of doing so but my problem is that I can't find a good reason not to SEAM weld the whole thing. I understand the theory behind it being that if there was a crack in one of the welds the full bead would provide a path for the whole thing to "rip" whereas stitching would stop the "rip" after only poping the "stitch" and not continue on.

My hang-up is that if the weld between any 2 particular pieces is COMPLETE from end to end and in the case of 90 degree welds continuous I don't see how the rip may start in the first place. I could even add a little extra rod/wire at the beginning and end of each bead to beef it up.

If anybody has solid theories or quantative proof (even better) it would be much appreciated.

Thanks!

 

Maybe weight? There's probably a point where it's stiff enough and the material that's added is just weight. Just a guess.

 

Yeah, I thought about that too but the added weight is minimal at the worst. I use 13lbs. spools on my machines and I could weld the entire car twice with that much wire.

Good point though, may just be a waste of time?

 

you need to post this on engineering tips

 

Some chassis flex is still necessary, no? I'm told that seam welding predisposes to a lack of the inherent flexibility needed whereas stitch welding allows for sufficient stiffness with still enough of the flexibility required. I've got nothing of substance to back it up though.

 

Where is engineering tips? Vooper that makes some sense I suppose, I'll search around for any info that might back that up.

 

No.

The suspension's job is to absorb bumps and manage the rate of weight transfer. Any flex in the chassis just makes it harder to tune the suspension in a predictable way, since it's hard to separate the effects of chassis flex from the effects of the suspension.

 

[QUOTE=PedalFaster,Oct 11 2010, 05:02 PM] No.

 

I read that article too, awesome by the way and I've drawn a lot of inspiration from it for my project. I have heard that before as well, though I'm pretty sure thats a crock, I've never heard of LMP of F1 cars being built to "flex" anywhere ya no?

 

Some flex in the chassis may be inevitable, but that's not the same as necessary...