Holy crap are you guys dense!!!
Have you ever taken apart your filter box to see the tiny hole that the engine gets to breath through ..... cold air or not!!
In this case MAKG is absolutely correct!! just adding an after market filter isn't going to make the slightest bit of difference. It can't because it isn't the restriction.
Anyone who tells you that a free flowing intake isn't worth power obviously has never bothered to try one!!
As I've stated before, I have first hand experience with the R&D behind the WMS cold air for the 05 and up Mustangs, and have personally seen the gains on the Dyno!!
Actually, for the first two years in business, I shared facilities with said Dyno.
I've seen hundreds of different combinations, before & after tests, and R&D sessions, and have yet to see a free flow intake that didn't make power (unless of course someone forgot to plug in the MAF sensor)
If you guys continue to give poor advice based purely on conjecture, I'm sorry but since no one will delete my account or ban me from this site I'm going to call you on it!!!
Better do your homework before you post something you've heard about!!!!