Avoid setting a computer radio's primary throw rate outside 90% to 110%. If you need more or less... do it mechanically as soon as practical. The servo torque and performance ratings are based on the normal "100%" throw range.

Going down, you decrease power by squareing the decrease in throw. (50% setting on the ATV... you have effectively got 25% power.)

Going above 110% can get into problems with over-ranging the position sensing potentiometer. its only designed to operate within a limited arc. You exceeed that arc and all bets are off on what the servo will do.

This is where computer radios teach bad habits... (and the JR advertizment of setting to 139% is asking for problems.)

The mechanical method of increasing throw in the previous post is correct. You first try to move away from center on the servo arm. IF you can't gain enough throw that way, THEN you try moving closer to the hinge att he control surface. Move one hole at a time at the servo or the control surface. If you have the threaded rod type aileron torque rods... 2 to 3 turns of the nylon adjuster, and move both sides the same amount.

On the Avistar (and some other planes), you can sometimes improve roll rate by just turning the clevices on BOTH ailerons out... moving both ailerons up a little. If the ailerons are adjusted with a slight downward deflection in "neutral" the roll rate suffers, and stalls become more likely to result in spins. Youdon;t have to move the ailerons enough to be easilly visible to make a LARGE performance difference.