I am no scientist and people claim that custom intakes don't make a difference. But, I can definitely feel an increase in throttle response with my Stage 1-3 Riss Racing intake. It doesn't give you the 20-30hp that some companies claim. The biggest gains come from adding DP's and a more free flowing exhaust. I'm happy with my purchase.
2013 M3 - MW, Carbon Fiber Roof, Competition, Cold Weather, Premium, 6MT, BPM Stage 2 Tune, MS Stage 2 Intake, Challenge Race X-pipe, Ultimate Clutch Pedal, M Performance Wheel