what are the considerations when choosing arb?
weight?
material?
diameter?
type of mounts / bushings?
I think ARBs are quite low-tech, so there wouldn't be significant different-designed mounts/bushings. Same for the material - 99% should be using the same type (high carbon steel according to
WikiAnswers - What is the material of Sway Bar or Anti Roll Bar of vehicle )
Less weight of ARB is obviously better. Does it count towards unsprung weight (other than the struts/springs + brakes + wheels)?
Diameter - the larger it is, the more the body can resist torsion:
Strength of Materials
Since we've eleminated most of the factors in ARB design, the only real determining factor for suitability should be D. And then again, it boils down to a particular owner's planned usage of his car, eg. 2 FD2R - a 90/10 street/track vehicle will obviously have a different requirement from a pure track-registered one. And likewise, a gravel-rally Evo will obviously differ from a time-attack one.
My 2 cents, pls correct me if I'm wrong anywhere.