Originally Posted by Razathorn

You're confusing empirical results with what is actually happening to cause the empirical result.

On your losi, your rear roll center was probably on the low side, so raising it made it better over all. On the b4, you were probably a bit on the high side, and lowering it made it better over all. If you're roll center in the rear is wrong significantly in either direction, you're going to be loose. Too low and the car wants to flop over and wash out, too high and the rear just slides around out to lunch.

Removing washers in the front inside (raising roll center) almost always adds more initial steering on all cars. It tends to remove mid corner steering if you go too far.