Begin at any point on track:
Hold [Shift] + [Option] and click on a track position before the race begins. Note: This will start the race at "-1" laps.

Turbo boost:
Quickly shift into first gear when the bike is in mid-air while the front wheel is higher than the rear wheel. Keep the throttle up as the bike returns to the ground. Note: The rear wheel must hit the ground first for the boost.