S54 Carbon Airbox Variant 3 (E46 M3) -- Alpha N
The S54 Carbon Airbox is made of 100% carbon fiber including the internal intake runners. Alpha N version for use with Alpha N type of engine management, either via reprogrammed ECU (MSS54HP) or aftermarket stand-alone ECU. The airbox is available for fitment with an external air-filter. The CF snorkel provided is available in either 120 or 130 mm inlet diameters. The airbox utilizes tuned intake runners and larger plenum volume (Helmholtz resonance) to effect a power gain. The engine will have a more aggressive intake note and a better throttle response. The airbox works particularly well with uprated cams.