This has got to be one of the most insane vehicles you will ever see. It's a go cart with a sport bike engine. 300 lb vehicle and 119hp, IIRC.
http://www.youtube.com/watch?v=fKyTK-U3910
If you have played Gran Turismo enough, you will probably recognize the Nurburgring as the track used for this video and several others featuring this guy's creations on Youtube.
http://www.youtube.com/watch?v=fKyTK-U3910
If you have played Gran Turismo enough, you will probably recognize the Nurburgring as the track used for this video and several others featuring this guy's creations on Youtube.