[quote=“RRhodes” post=64596]I’m not trying to save money here. Just have no idea what’s required. My cage builder is in the drag industry, he has no real experience with road racers. I’ve seen many designs with variations on this theme including NASCAR style, vertical bracing, gusseted X’s etc. No matter how you slice it in an impact both bars will be under tenstion (except real NASCAR designs) and trying to shorten the distance between the main hoop down bar and the front vertical.
The NASCAR bars change this by adding clearance, putting the door bars under compression, and forcing the verticals apart. Probably a much better design overall but I want to go down this path and fix the design problem by avoiding getting t-boned ;)[/quote]
This is an oversimplification of how the different structures respond to shear and “moment” forces. Any mechanical or civil engineer will agree that an X is far stronger then two bars supported only at the ends. A gusseted X is far stronger than a non-gusseted X. It’s not so much the stiffness at the anchor points because we all have the same number of anchor points. It’s about the stiffness of the structures between the anchor points and their ability to resist t-boning by distributing the load among the X’s 4 beams. Or, in the case of NASCAR bars, turning what would be moment forces into more easily resisted shear and compression.
Useful additional note. Measure the height of your front bumper and use that as a guide on where to make the side bar structure particularly stout.