my rush has greys/ t34 / cams / head work etc and fwd. after about 300bhp you have trouble getting power down on 2wd although i havent tried it with soft tyres.

another problem with the rush is finding a way to get decent intercooling and engine cooling. the standard intercooler that people use in rush is cossie 4wd but the air flow is poor and since it sits 6 inches behind the engine rad its not a good choice.

also the rush with cossie weighs about 750 kg and bike engine jobs around 450-550 kg. the ultimate solution is a turbo busa or possibly a turbo 1200 kawasaki which runs about 300bhp for £3000 for the turbo upgrade. when it goes bang you get another base engine/box for £250-£400 and spend a couple of hours putting your turbo goodies onto that. you can lift the engine in and out with a peice of string. the way to go i reckon.

my car keeps up with all the bike engined ones ive met except turbo jobbies