I just want ask question; are the pressure in the crossover pipe before the throttle butterfly and the pressure in inlet mainfold (when you connect boost gauge) must be same? for example , if pressure in crossover pipe is 10 psi, how much must be pressure in inlet mainfold (or on boost gauge)?

this is really important to me

thanks

 

The pressure readings will be different, this also depends on the amount the throttle butterfly is open.
The boost guage should be connected to engine side of the throttle butterfly as this is the reading of boost pressure that the engine is seeing.

 

boost gauge must always be connected after the throttle bodie, in th einlet manifold

 

yes, I know all but there is no boost. I have boost only in crossover pipe. maybe some air leak somewere?