Alrite, I use a boost gauge that shows vacuum pressure down to 1 bar or 100 kPa. At 1 bar=14.5Psi, the needle should show 17psi at ideal but no way in hell my gauge can show that. Instead it shows 0.7bar, or around 10 psi. I had a psi boost guage and it was showing 17psi at idle.

am I doing the conversion wrong?

Most metric boost gauges only goes from -1 bar to 2 bar so none of these work?

Kevin

 

edited for clarity*

vacuum for the psi gauges are not measured in "psi"

its measured in inches of mercury(Hg)

17 inch mercury corresponds to:

0.57568608 bar or 0.5870364294 kg/cm^2

notice bar and kg/cm^2 are not equivalent. but close enough.

another common unit for vaccum is mmHg, that can be calculated by a simple conversion from inches to mm. 1inch = 2.54cm = 25.4mm

 

btw, your gauge reading of .7bar is ~20 inHg, which corresponds correctly(close enough anyway) to your old gauge reading of ~17inHg