[vector1]

realistic is what you can afford. how much do you want to spend on the engine? do you have to upgrade other parts and are you willing to spend the dough? then, can you actually use the hp you have budgeted for? lightweight drivetrain is easy hp, always there, and seldom breaks.

how much faster is a 600/600 engine than a 500/500 in the quarter, or even 400/400? then take the same comparison on a road course and see who can use the hp in the twisties.