What is the intake pressure channel number for Volkswagen?
1 Answers
Volkswagen intake pressure does not have a channel. It mainly relies on the engine speed signal sent by the crankshaft position sensor. When the engine speed reaches the set value, the engine control unit activates the solenoid valve circuit, opening the vacuum line to operate the intake flap. The working principle is as follows: 1. Intake valve opening: When air flows into the cylinder, due to inertia, even after the piston reaches the bottom dead center, air continues to flow into the cylinder. If the intake valve is closed when the cylinder pressure reaches its maximum, volumetric efficiency will be maximized. This effect is known as the inertia effect. 2. Cylinder pressure reaches maximum: To achieve optimal volumetric efficiency, both the pulsation effect and the inertia effect must be considered. This means that when the cylinder pressure reaches its maximum and the intake valve is closed, the compression wave in the intake manifold also reaches its peak position (wave crest). 3. Intake manifold: A longer intake manifold provides higher volumetric efficiency at low engine speeds, resulting in higher maximum torque. However, as speed increases, both volumetric efficiency and torque drop sharply, which is unfavorable for high-speed operation. A shorter intake manifold improves volumetric efficiency at high engine speeds but reduces the maximum torque and delays its occurrence. Therefore, to balance power output across both high and low engine speeds and maintain volumetric efficiency at any speed, a variable-length intake manifold must be used.
