You should hear my MotoGuzzi...

Vibrates the floor at low revs then screams like a Duke 888 when you open up the throttle. Amazing the change in engine noises from £5k worth of tuning! (Gilding a turd etc etc, I've heard it all - but it's faster than a Cbr6 to 80ish, and 30 times as cool, especially being a venerable 30 years old.)