To get 250 from a sc, you are gonna have to dish out money for headers, catback and intake atleast. Those things with a supercharger will net you just over 230whp... check around for dynoplots. Also the belts on the sc have to be changed about every 10k miles. You could upgrade the sc pulley to get 9psi which would get you to roughly 260whp (with the above mentioned items you have to buy). To do that you will have to get another fuel management to handle the extra boost. Also sc doesn't have anything to cool the air so running that much psi would increase your chances of detonation...aka engine go kaboom. This is the reason I went turbo instead of sc, plus there is more room for improvement incase I get bored of the power and want more. Either way, both have it's ups and downs and cost lots of money.

Don