Boxster (986) F6-2.5L (1998)
Blower Motor: Description and Operation
Ram Pressure Compensation
The airflow is influenced by the ram pressure which is, in turn, dependent on the vehicle's speed. To compensate for this relationship between ram
pressure and vehicle speed, the ram flap is actuated in the "closed" direction according to the driving speed > 56 MPH. The flap position is also
dependent on the blower voltage.