[Taekwondoin]

Can't really comment on bikes, but i know on modern supercars (think Nissan GT-R) the limiter is an integral part of the ECU, and to remove it completely disables the car. Of course, that's just to get around Japanese law that manufacturers are no longer allowed to make cars that do over 112mph, they have a very clever satnav though that knows when they are on a road (so it's limited) and when its on track (unlimited).