Hello from Greece.
I have mod the M271 ECU (SIM4LKE) from my MB, and reach 206RWHP at 6.800rpm, which is a decent power. The problem I have is that even I set the ECU to read the max boost which is 1bar (the factory map sensor can't read more), after 4.500rpm the boost start droping at 0,85bar. After logging the ecu readings, I realize that the MAF sensor reads 182g/s maximum, even if the supercharger is spining at 17.000rpm (factory pulley setup) or at 20.500rpm (custom pulley setup). The MAF ends at 4.500-5.000rpm and from there till the redline the readings are at 182g/s. My opinion is that even the sc is cable for making more boost, when the MAF max out, the ECU must use the electronic bypass valve, which located at the back of the sc, in order to keep the boost low. The M271 MAF has 5 pins. I have put bigger MAP sensor but nothing change. Trying to change the MAF values, hearts idle and performance. One idea is to make a bypass to the MAF inorder to put more air to the motor and clamps the MAF readings. Can anyone help me or has any idea for that. Thank you in advance.
The car setup is:
Crank pulley 195mm
Supercharger pulley 62mm
K&N filter
Aluminium piping from SC to TB
Bigger IC with water spray injection on it (Max IAT at redline no more 40 - 42oC on a hot summer day of 32oC)
Fuel Pressure Regulator 5bar (3,8 OEM)
Free flow headers with one metallic cat 200cells under the floor.
The EATON M45 has been ported and cable to make at least 1,2bar.