Intake System V6 DFI

Intake System V6 DFI







Air routing from the air cleaner to the electronic throttle was dethrottled for the new 3.6 l V6 DFI engine by use of the new mass air flow sensor HFM 7. This optimized hot-film mass air flow sensor improves the air throughput of the intake system by reducing the intake air resistance. This results in improved cylinder charging.







Hot-film mass air flow sensor HFM 7

- In the measuring tube on the right next to the MAF sensor there is a special air guide element to optimize air flow.
- The flow characteristics of the bypass duct have been optimized compared to the previous HFM 5 model. The vacuum behind the deflection edge draws the partial air flow required to measure the mass air flow into the bypass duct.
- The inert dirt particles are left behind by this fast motion and are returned to the intake air via an elimination bore.
- This means that the dirt particles cannot falsify the measurement result and damage the sensor element.







Variable intake manifold

Like in the previous model, a variable intake manifold is installed in the new Cayenne V6. The intake system with variable intake manifold combines the advantage of a long intake manifold - higher torque at low rpm - with that of a short manifold, namely high specific output in the upper rpm range. For this purpose, the resonance tube uses the air mass oscillations in the intake tract, dependent on the engine speed, to achieve better volumetric efficiency of the engine. Depending on the position of the intake manifold flap, this permits realization of a high torque curve in conjunction with the optimised intake duct geometry.

The DME control unit controls the electro-pneumatic switching valve, which switches a vacuum to the diaphragm cell in order to switch to the long intake manifold length at low engine speeds. Switching to the short intake manifold takes place as from 4,200 rpm.