Question about setting psi on high-speed leanout

I have a poppet style hi-speed can and am having difficulty setting the crack psi - which I want to be at 55. Using a regulator, the bleed starts well in advance of 55 psi with various spring & shim combinations and with the regulator wide open I'm up at over 70 psi. Is the desired pressure read when the regulator is wide open?....or when it is determined when the poppet is just lifted off the seat? I even tried setting the can in water to determine when the pressure blows the poppet of the seat, but all I get is a progressive increase in airflow, and can't determine the pressure when the poppet seat is lifted. Any help would be appreciated. Thanks all

 

Mike, do you recomend setting all your pressures that way? Secondary, Main and High speed, I get various readings also, so this makes sense.