This is how the variable intake manifold is made.
It can be opened quite easily
the ECU switches the manifold between short and long runners as follows:
I can now confirm this, the corresponding 1D maps inside ECU define two switch ranges: 2720-2760 and 5000-5080 RPM.
- idle - 2800 rpm - short
- 2800 - 5200 rpm - long
- 5200 – rev. limiter - short
In the short position long runners are open in the middle to leave a small gap between both parts.