Scanguage II - Xgauge boost settings

[azzacalabaza]

Hi all. I received the Scanguage in the mail today. I have set up boost gauge as per this document.

I set at 13.2PSI atmospheric pressure for Maryborough QLD. (I hope that is correct).

The guage shows 1.3PSI at idle. Is that normal? should it be at 0?

[azzacalabaza]

Just took it for a drive to the shops and on way back nothing was showing up for boost on lcd.

[Rock Trol]

Hi all. I received the Scanguage in the mail today. I have set up boost gauge as per this document.

I set at 13.2PSI atmospheric pressure for Maryborough QLD. (I hope that is correct).

The guage shows 1.3PSI at idle. Is that normal? should it be at 0?

Yes, thats normal as the atmospheric pressure is not constant but varies during the day. The High and Low weather troughs you see on the news will affect that as well. Its common to see a little bit of boost when idling. If you want an accurate measurement then set it to MAP (Manifold Absolute Pressure) which will show you the true pressure in the intake manifold. For example when idling it will display 13-14 psi or there abouts and when under boost it will climb. Mine boosts up to 33-34 psi max.

[the evil twin]

^^^^ Wot he said X2

Most times you want to know the engine cylinder pressure as too much bends rods/blows gaskets etc

MAP is absolute pressure (Boost plus atmospheric) and that is what determines the cylinder pressure after compression.

Boost Pressure is only a measure of how well your Turbo is doing

[azzacalabaza]

Thanks Guys. So what your saying is if you use MAP setting you just need to deduct the atmospheric pressure from the recorded pressure to get turbo pressure?

Sorry to ask dumb questions. I know about as much of mechanics as I do brain surgery.

[Rock Trol]

Thanks Guys. So what your saying is if you use MAP setting you just need to deduct the atmospheric pressure from the recorded pressure to get turbo pressure?

Sorry to ask dumb questions. I know about as much of mechanics as I do brain surgery.

Yes, thats correct. You wont really know the exact atmospheric pressure at any given time but an average like the one you added will give you a ball park figure.

[azzacalabaza]

Awesome. Thanks again everyone.