Aetro wrote:
I was looking at some F1 suspensions and wondered if anyone knew of any advantages of having super long wishbones.
Long wishbones are common on formula cars of any class, formula ford is an excellent example. It's simply the inevitable result of having a wide track and a narrow chassis, rather than a goal they had in mind when they where designing the car.
The only place I can think of where long wishbones are a design goal is long travel suspensions on purpose built off road vehicles like dune buggies, Baja trucks, and the like. The benefit in that case is that a longer wishbone allows greater suspension travel for the same misalignment in the ball joints and CV joints.
On a locost, there's no real benefit.
Aetro wrote:
This seems to be good up until 3in of bump where the RC goes below the ground. Almost the same situation at 5* of roll. How important is the side to side movement? should i try to limit its migration?
In bump, don't pay any attention to RC migration with respect to the ground. What matters is the vertical distance from the RC to the Cg, which is what determines your roll moment and roll inertia. In bump, you
want the RC to migrate downward. To be precise, you want it to migrate downward at the exact same rate as the Cg migrates downward. For three inches of bump you want three inches of migration. And the tales of doom regarding an RC below ground level are old wive's tales, it's really not important. If RC height is migrating from substantially positive to negative in roll, you're going to have nasty handling, but not because the ground is a sacred boundary that must never be crossed.
As for lateral (kinematic) RC migration, it's important in terms of force based roll centers. If your kinematic RC doesn't migrate vertically or laterally, then your force based RC won't migrate vertically.