I know this may have been covered but its more of an observation...
When i fitted my Inovate boost gauge i used a T peice to the DV vacume pipe. It worked fine and read steady.
After a day at JBS looking at a few problems they moved the gauges pipe work to the fuel preasure regulator... With the reasoning that when the dv was actualy in operation it would give the gauge a false reading??
Since this was done from time to time the needle flickers and doesnt hold still. Kind of like a vibration on the needle.
Why is this and is it better when fitted to the FPR instead of the DV??