It robbed you of power? I've read loads of posts on here re cone filters and this one in particular that increase HP (albeit marginally) due to the velocity stack in thse filters? Jardo / Prawn please correct me if i'm wrong. Its the spool up noise i'm after anyway but i dont want to lose HP!
Mine was defo down on power with it on, but to be fair i think it may have been a heat sink issue. i put the standard box back on and it felt much better, maybe i need to fabricate a heat shield?