[Excaliber]

Ideally the upper and lower ball joints would be near zero in alignment up and down (top and lower) when first installed with ALL adjustment potential positions in the "middle" of their range of adjustment.

From there you can reposition the upper ball to "lead" the lower ball. Like the "castor wheels" on a chair. When you push the chair, the wheel kind of spins around to follow the leading edge of it's mounting point. This is positive castor. Thats what makes your steering wheel tend to "straighten out" by itself after you turn a corner. It's the "castor" effect of the upper and lower ball joint relationship.

Camber is the top of the tire leaning in toward the car, or away from the car, or "zero", straight up and down in relation to the side of the car.

Toe-in is where the front edge of the front tires (or rear in IRS) are either "pigeon toed" in, or out, or zero, straight ahead.

Again, with ALL possible postioning nuts, screws, shims and other "alignment" items in the "mid position" these THREE critical alignments (camber, castor and toe) would be near zero. Now you can adjust all three TOGETHER at the same time to "dial in" your alignnment.

Alignment is done with the car sitting on a level surface, normal ride height, wheels straight ahead and all that. As soon as you "hit the road" and take a corner, the car leans, one coil spring is compressed and the other is lifted. The suspension "moves" up and down. As it does the relationship between camber, castor and toe start to "change". This is called "bump steer".

In an ideal and perfect world the relationship of the THREE alignments will always stay in perfect relationship to each other as the wheel moves up or down on either side. In the "real" world and unless you have some "exoctic" suspension the relationship WILL change, you WILL have some bump steer.

Some cars have less, some more. Sounds like FFR may inherently have a condition where to much "bump steer" is a fundemental design flaw. The "three" can still be adjusted, but the MORE adjustment you have to do to overcome the basic design flaw, the worse you will make the "bump steer" issues!

Solution? JBL of course, zero bump steer!

Ernie

Edit: Unless your a "racer" who is really in "tune" with the handling of YOUR car, you would probably not notice a "bump steer" condition. But exiting a corner at high speed under great "load" with "bump steer" could mean the difference between a "crash" and "making it" through the turn!