It looks like something is wrong with your boost gauge. It display 0 when you are idling. Normally, it should be in vacuum (under 0 PSI) at about -20 in-Hg (around -0.6 bar).
Example of a working boost gauge : http://www.youtube.com/watch?v=l4HtaqUa-QA...feature=related
Example of a working boost gauge : http://www.youtube.com/watch?v=l4HtaqUa-QA...feature=related



















