1996 Audi RS2 Brilliant Black

[NasTnaS]

What is the NO and NC port?

[le mans]

It's the ports on a 3-port boost solenoid.

NO = normally open (when solenoid is de-energised)
NC = normally closed (as above)
C = common (always open)

This is a good reference point: https://www.onpointdyno.com/boost-control-plumbing-get-it-right-save-money/

[NasTnaS]

Interesting typically the port names are usually 1,2,3 for a 3 port 2 position valve and the NC and NO refers to its de-energised state.
We use many pneumatic valves ( 5 port, 3 port, 2 position, 3 position) etc and haven’t really seen the ports referred to as NC/NO before.

Hope it’s going well. It’s an awesome care.

[le mans]

Ah right. Yeah they are numbered 1,2,3 on the solenoid itself. I find NC, NO and C easier to understand without having to remember what the numbers refer in terms of on/off state.