Originally Posted by target
I must be doing it wrong, I usually increase diff with speed, and decrease rudder mix with increased speed.
This has been (seemingly) working for me so far, but I haven't tried the opposite yet.
That may work for you in F3F where you guys tend to pull up for a turn (and during roll the pos. Diff makes the fuselage point downward into the turn).
In F3B this is not that good: I try in a speed and distance run never to pull up, the plane is always monotonously descending. The nose is always pointed downwards, at every moment in the run at an almost fixed rate. Therefore I want an axial roll, would it be slightly pointing down, it would loose too much altitude in each turn (pulling up would destroy speed). This sounds anal, but if you fly 30+ laps and loose a feet every turn, then that costs too much altitude. The same in anticipation for a speed turn, I don't want to loose too much altitude.
Further you can keep the plane for a moment in knife edge to anticipate a turn, even in medium speed distance, when the roll is axial and has no up or down pitch. If the differential would be slightly pitching, it is much harder to keep the glider in knife edge, even for a short moment.
This is how I leaned it from Quabeck's book and the Boehlen Bros, and it works for me well.