[Richard Hudgins]

Bob,

How bad are the jacking effects with the Jag geometry?

I have always wondered about the lower arm angle and what the jacking forces are.

Now, to be honest, Jags are some of the finest behaved chassis that there are.

The JBL theoretical swing axle radius on the rear is a bit longer than what you show (Close to 345 inches.) and the front is 120 inches. (I really like long moment arms to slow down the dynamics.)

The Front RC is "0", the rear ".625" at normal ride height. I also like a pretty flat Roll axis with this CG and weight distribution. (45/55.)

Also, the angles are such that no jacking effect is implied under roll conditions.

I have found this combination to work fairly well and produce the dynamics that I desired for this chassis.

It is not at all what I would do for a Aero car. But for this type of application it seems work OK. My wheel rates can remain low, damping rates in the 250's and then roll rates control the rest.

But as we both know, there are many ways to skin the cat.