Plumbing!

I plumbed the gauge into the original dash feed and I was reading a steady 0.7 bar, so it seems the actuator is set correctly. Anyway I've left the gauge plumbed in here, as it works well enough. Like you said David, it just doesn't show vacuum.

So I fitted the boost upgrade kit and at full boost it's peaking at 1.0 bar, then holding a steady 0.9 bar. The boost cut out was kicking in at this setting, so I've wound the limiter back to remove it and left it at that. I'm happy with this for now. It's giving some noticeable extra ooopmh, so I'll run around like that for a while and see how it goes.