One trick i always use to get great times, is to use the up and down buttons to your advantage. This takes a lot of practice. But you can use it to above the track and use it to cut hard corners. This usually only works on phantom.

A good place to practice is the first real turn on Klies Bridge. Just as you get to the top, just before dipping fown to the 90 degree turn, hold down and left and try to manouver yourself to go on the inside of the turn and land just before the cave.