I got almost 90degree in mine rudder with a Fut 9404 servo mixing flap to ele 140% both ways all the time because it seems to help keep the plane from torquing as bad. I am running one of the new OS 50 2stroke on mine with a mac 2 piece header and tuned pipe with a "wood" 12x4 turning right at 16000 on the ground. Balanced mine were it was still a little tail heave with a full tank of fuel to help with the hovering & also helps loop tighter. Some of the guys I fly with are running "wood" 11x4 props on theirs had having good luck. To keep from having to add as much weight to the tail get your bat in behind the servo tray.
Really good plane for the price I got two of them.
There is not anything a little extra power will not help.