I get my reading from right out the supercharger (on the s/c outlet) and right on the manifold.

Piping is 2.5" and my intercooler may be the cause, but IDK yet.. I have a smaller/smoother flowing one on the way to see if theres any changes. Once that gets here and the new clamps, if theres no change then I will pressurize the whole system to boost leak test.

Loosing 4psi out of 14psi on an intercooler is an unheard-of pressure loss