Can I use HFS-2 instead of HFS-3 for my 335i setup ?

[Richard L]

The HFS-3 system is already set to triggered and progressive with IDC from factory.

The second jumper link (from left) is labelled as IDC (default). If you want the system to be triggered by boost. Move the jumper link to "MPS" (manifold pressure sensor).

Slightly further towards the right, The system can be set to either "progressive spray" or "on/off". Factiory default is set to prorgressive (PWM).

The system can also configured to communucate with the any piggybacks' failsafe, based on actual flow.

Does you have good logging capability with Cobb?