I have downloaded a few world record time trial ghosts. In them (as expected) they take corners perfectly, execute shortcuts precisely and generally fly around the map ridiculously quickly.
But it seems that a key part of the strategy is to constantly jump and turn (even on straights). Whenever I have tried this it has resulted in me slowing down or turning off course.
What is the technique to doing this? How does this actually cause the karts to go so fast?