i brought this 2nd hand, not sure how to fit it.

managed to it to come alive by connecting 2 of the 3 wires to a live and earth, power came on and needle did a sort of start up , went from 0 to 2.0 the to -1 the stopped on 0

in the photo there is a copper valve, does this have to take a tube to the engine bay then be T ' d in somewere ? ? ? seen loads of video's etc but need to know what sort this is and how best to get it working properly.

thanks in advance.

The pressure sensing part of the gauge should be connected to the inlet manifold after the turbocharger. This will tell you how much pressure the air is being fed into the engine at. If you double the pressure (Take the gauge to 1 bar from atmospheric pressure = 0 bar by the gauge) the engine should put out similar power to a naturally aspirated engine twice the size ... Make sure you find out what the engine is rated for first though - high boost pressure kills engines. You may have to put an orifice plate between the manifold and the gauge to stop it picking up the pressure changes as the inlet valves open for each cylinder and smooth the signal. I've not done this though, so I can't recommend a method to connect, but if all else fails I'd go to Swagelok.com the source for tube fittings, valves, and other fluid system components and look for suitable compression fittings...