Originally Posted by ndogg

RCA lowers where the lower arm attatches to the hub. This changes the angle of the lower arm to raise the roll center. Since the shock mounts to the LCA right by there it lowers the shock thus lowering the car. The preload on the shock is not effected though so you don't gain any bump on the shock.

Originally Posted by robrob

Nope, I was wrong before I was right
I knew this discussion would happen. Take a look at the pic below. The weight of the car is resting on the lower control arm through the shocks. When you install roll center adjusters (before you make any other adjustments) the only thing that changes is the hub is raised and the upper control arm angle changes. This angle change is how the roll center is raised. Note the lower control arm and shocks don't move.

If you put the wheels back on and lower the car to the ground the car will now be about 3/8 inch lower than it was before the install--and this is the important part--the shocks are in the same place meaning they haven't been lowered toward the bump stops. To get the car back to the original ride height you have to adjust the coil overs to raise the car--thus you're gaining bump stop clearance.

Originally Posted by ndogg

Ahhh, ok. So when you do lengthen the shock to get the ride height back, the upper arm moves back into the same position it originally was, and the lower arm is now the one with the changed angle, correct?