I have the torque app and adapter and have a question. When I look at the boost gauge on it, I show vacuum, not boost. Is this normal? Am I looking at the wrong thing? By the way, I'm using a digital display, if that matters.
Thanks

 

You have to be making boost to show in on the gauge...

 

OK. Dumb question as I'm new to turbos. WHEN are you making boost?
Thanks

 

Under light throttle or idle, the entire intake train, from the airbox to the manifold, is under vacuum pressure (lower than atmospheric pressure), just like any naturally-aspirated engine. The turbine isn't really spinning at idle, so the compressor isn't building pressure. As you increase throttle, exhaust pressure will start to turn the turbine, which turns the compressor, which compresses the air. The air pressure downstream of the compressor will go from negative pressure (vacuum) to zero, to eventually positive pressure. So a proper turbo boost gauge will have both a negative and positive pressure region.

 

I run the Torque App too. I have to admit, it is a bit misleading...When I get in the car, vacuum gauge reads "Vacuum". I drive down the road and put my foot hard into the accelerator, the vacuum gauge changes from vacuum to "Boost". Go try it, you'll see.