So all ive got performance wise is a K&N filter, cat mod and custom exhaust. (So far). When im on the freeway doing like 75ish and punch it my truck seems to just fly and the RPMs are way up there. Now normally my truck craps out past 4 grand or so im guessing cause of the powerband. My question is, am i getting some sort of ram air effect from the speed? My air box lid is open but that really shouldnt make a difference. So whats the deal? Anyone?