Taco gussets vs triangular gussets?

[Seralan]

I think I like the idea of using the taco gussets on the cage intersections. Are they any better or worse the the regular triangular style? Do they have to match the wall thickness of the tube? Would I need to punch them to provide access to the tubing welds for tech?

Any info or opinions would be appreciated,

Thanks,

Alan

[Mopar 151w2]

Just my opinion - "Tacos" are better than single- thickness gussets, 'cuz they spread load over a wider area, and in line with lhe walls of the tube.
I would'nt sweat using an .083 gusset on .093 tubing, but the .060 gusset on the .134 tube strkes me as pretty dumb. I would'nt think an inspection hole would be necessary or required, but it's not a bad idea.... Dimple-die the hole for "fabrication stud of the week" points.

[walterclark]

We dont specify a minimum thickness for a taco style gusset. The FIA requires they be at least 1mm and we will accept that. But that is the equivalent of about 20ga steel and in my opinion way too easy to tear thru. I recommend tacos be at least twice that or about around 14-16ga and flat gussets be at least 11ga. We dont require the taco be cut away to permit viewing joint welds behind them. We will permit a small radius cutout in the taco at the tube joint - the FIA permits a radius no larger than 1.5 times that of the tubes being joined so we will accept that. Some fabricators will punch or drill a hole in about the middle each flat surfaces of tacos which is OK, but per the FIA the holes shouldnt be larger than the OD of the tubes being joined. If you get a sense of a theme here... If we dont specify something, then we will accept what the FIA says in App J Article 253 about it. So if you were to build a complete cage to current Art 253 standards for fabricated cages it would be accepted by us (and a lot of other sanctioning bodies).

[Seralan]

Thanks guys,

I figured that the FIA specs would be acceptable, but wanted some reassurance. The car should be less the 2500lbs total when I am done. I am going to splurge for 1.75" .095 wall dom tubing for everything (only need one bend die). It looks like using that conservative approach I'll be legal for NEHA , COM, and even rally America if I want to go broke again.

As far as the gussets go, I modeled them and the tacos have a lot fewer stress risers then the single plates. I'll plan on running .0625 sheet for the gusset material thickness. I'll probably punch and dimple die all of the gussets to provide some weld view. It's hard to believe anyone would skip out welding that part of the......forget I said that. I'm looking to be as safe as I can even with a weight penalty. I also want to pass tech without having to grind, cut and weld.

I really do appreciate all of your input,

Alan