Ram Air Pressure Compensation
The air volume entering the IHKA system is compensated for at higher vehicle speeds. This is carried out through the road speed dependent fresh air flap operation.
In the fresh air mode, the flaps are open 100% up to a road speed of approximately 37 MPH at which point they are closed to 40%.
When the vehicle speed reaches approximately 55 MPH the flaps close to 30%.
There is a hysteresis (overlap) built into the flap closing so that the flaps will not oscillate open/closed at one set speed.