Hey all,
I've been wondering lately about the relevance (if any) of rear suspension caster, KPI, scrub radius, and caster trail/offset, not to mention fore/aft spring location on vehicle dynamics/handling on a SLA double-wishbone setup. I would suspect that these parameters are responsible for lateral/longitudinal force wheel compliance, in that scrub radius and caster trail cause toe-changes when longitudinal/lateral forces are applied. I would imagine that caster trail needs to be negative (i.e. behind the wheel) to give lateral force understeer (resulting moment wants to steer the wheel into the turn) whereas scrub radius should be minimized to minimize toe-out under braking. It might also be useful to have the coilover mount onto the rear upright (instead of on the wishbones), and have it do so aft of the rear wheels so that it preloads the upright/wheel in the toe-in direction - or is this a bad idea?
Here are some pics of what I had in mind
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Comments? Critiques?