Differential Air Intake System (DISA)

Vehicle: E36 - M42/M1.7, M44/M5.2







DISA allows the dynamics of the incoming air charge to take advantage of a long pipe at mid-range RPM. This produces a ram air effect that increases engine torque at mid range. At high speed the change over valve switches allowing the engines breathing dynamics to switch to the short air pipes.

This change enables additional power output at the upper RPM range. The change over valve is held normally open by spring pressure and closed by vacuum.Control of the DISA solenoid is an output function of the ECM. DISA is the intake manifold arrangement on the M42 and M44 that provides the advantages of both long and short intake pipes.

The system is activated initially by the ECM which provides a switched ground to the vacuum solenoid valve. The balance of the system operates via vacuum/mechanical functions.