as already said bikes will always be faster than a car due to the weight, bit different on track as they have less grip in the corners but make up for it on the straight
clarkson done a test like that once with a r1 ridden by a british superbike champ against a porche 911 carrera 4 driven by jason plato, the car won round the track
http://www.youtube.com/watch?v=_UDXcotDqDs
if the track was less bendy i reckon the bike would of won
ahh joe's ford gt tt got to fucking love that car
That was years ago. Bikes have come a long way since then.
Obviously there are tuned Fords that can beat bikes in a straight line, but the difference with a bike is that for £6k you can put £300k cars to shame.
They are good fun.