Below is the quietest automotive racing video I have ever seen. It was taken at the Time Trials Extreme Grand Prix -- an electric motorcycle race.
The winning Team Agni's bike is a converted 2007 Suzuki GSX-R 600. It comes equipped with two Agni 96 motors and a Kokam lithium polymer battery. The lap was made in 25 minutes and 53.5 seconds, more than 3 minutes faster than second place winner XXL Racing, and four minutes faster than Brammo.