E46 M3 gets a Carbon CSL style airbox, bespoke mafless ECU remap, twin plate clutch and short shifterIt’s difficult to get more power from the already optimised E46 M3, short of supercharging the best way to improve power, torque, driveability and response is through installing a carbon fibre style CSL airbox and removing the factory MAF sensor.
The CSL airbox not only provides a tangible increase in power and torque alongside ECU software to suit but, also greatly improves the engine bay aesthetics and gives the S54 a truly amazing intake roar. 
Once fitted, and the ECU software mapping session initiated the factory clutch started slipping. The customer ordered a UUC Twin Plate clutch to handle the torque and UUC short shifter to improve shifting. The clutch has the added benefit of having a much lower mass than stock, especially important on a part which rotates. Meaning in lower moment of inertia, resulting in improved acceleration and quicker shifting. 
Once the gearbox upgrades were installed it was time to map the CSL airbox equipped E46 M3. With mapping complete, the vehicle developed 369hp and 269lbfts, with smooth curves. Customer comments that the car feels much faster on the road, with silky smooth driveability!
Regal Autosport supply and install many performance upgrades for the E46 M3, including those listed above to full blown 570hp+ supercharger systems to suspension and differentials.
Contact a performance specialist to see what Regal Autosport can do for you by calling 02382 550958 or emailing sales@regalautosport.com.