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