So I have been doing research about installing a eurocharged sc pulley and ecu tune... How is it that the site claims it will put your car over 400hp... Yet youtubers video their cars with this exact modification and needswings CAI to boot - and their vehicle dynos at 348 which is actually not that much of an advance from stock... Am I missing something? Please break it down for a noob in lament terms. Thanks!

I just want to make sure I am not paying a grand, plus... For only 10 extra horsepower. That seems ridiculous.