A 1/16 of a inch between the ailerons will get you where you need to go. Try this: 1/4" on the up aileron, 5/16" on the down aileron. Set these #'s as your max throw (or high rate if you have dual rates) or tame it down to your flying style (or less throw on low rate) Do not go anymore then a 1/16" of a inch on Aileron differential. It will mess up how the plane handles in other areas.