[stevocan]

Hey guys, I own a 2008 BMW 335i 6speed currently on mhd stage 1. Whenever I push in the clutch and hold it there, no matter which gear it's in, and rev the car I feel like the engine is held back. It doesn't have the same free-revving nature as if it were simply in neutral with the clutch out. I found a video describing my exact problem: 

I have no symptoms driveability wise. Also, there are no unusual noises on idle both with the clutch in or out. Really just when I try and rev it. Has this ever happened to anyone and solved it? 

Thanks