Where to find a cheap valve to switch between 2 vacuum ports

[ciper]

Help be brainstorm. I'd like a valve with three ports on it, one output and two inputs. When no power is supplied it should default to a connection between port 1 and 2 then with 12 volts it should connect port 1 and 3.

My purpose is to monitor boost pressure at the turbo and inside the manifold. After a recent day at the track acting as the pit crew for three impressive Subarus I realized how useful this would be. Specifically I could have used it to help troubleshoot a failing BOV.

If my thinking is correct it should help to determine the current efficiency of the intercooler. If the intercooler is very hot it shouldn't cool the air much and the pressure drop would be normal. If the intercooler was cold it should condense the air and the pressure drop would be greater right?

I'm thinking I can use a boost control valve for the purpose.

[93forestpearl]

You could get yourself a GM BCS for the Typhoon. $26 brand new and you can get the plug off of any GM washer fluid pump.

[Legacy777]

I think you can use the valve for troubleshooting, but as to determine intercooler efficency, I don't think you're going to see much, if any of a change.

[ciper]

In a way I was hoping it would be the case. People often talk about pressure drop across the intercooler and I'd like to see if it's really as big as they say!

[Legacy777]

You could probably look at pressure drop, which would be beneficial, but I don't think it's going to change much based on air temp, nor will it give you efficiency.