[psy_wombats]

That code above should produce a curve that reduces the motor outputs when the joystick is at a low level, but still maintain a max speed. (See attachment.) Of course, you could just multiply by some fraction, but that decreases your top speed. Or maybe reduce speed when motors are turning in opposite directions, (turning?)

The reason it's cubed is to get that sort of curve for the entire function. The random huge number in there is 128, (the maximum value) squared. It's basically to center the cubic equation on 128,128. (I believe I came up with it with experimentation on a graphing calculator, I really forget why it works)