SL Airbox is one of the most demanded improvements among BMW M3 E46 enthusiastic. That is both for performance gain, and for sound it brings to car. On the other hand, it is a laborious, time-consuming and expensive modification.
For those who are looking for similar sound to CSL airbox but do not look for HP gain, we have developed the Karbonius OEM Style S54 airbox.
It is a simplified version of CSL airbox, that, apart from louder sound to engine (+12 dB compared to plastic OEM) gives awesome appearance and easy installation using stock elbow and MAF
No needed to remap
*Need to install with CSL Crakcase breather hose (RealOEM ref: 11157833649)
*In SMG version, need to install genuine BMW CSL SMG Expansion Tank – RealOEM ref 2153228254949)
Regarding power increase, we got +4HP in recent dyno test comparing with OEM airbox. Not really significant considering that dyno can have a 2% margin error. In conclusion, and pending new test in future, we can say no significant power increase and no HP loss.
• BMW M3 E46
• BMW Z4 M
As usual, piece manufactured 100% in carbon fibre prepreg, cured in autoclave in our facilities in Spain (EU) under strict quality requirement and for qualified stuff
*Please notice customs fees in country of destination are not included in price