my understanding of it is that the pressure loss will be coming from the intercooler cooling the air, combined with slight flow/pressure loss from the pipework and intercooler
what size is your charge piping?,
you would probebly want 2 1/2"

also where are you measuring the pressures from on the intake side?
in the intake plenum after the throttle butterfly of before the butterfly just before the air goes into the intake? i say this because maby the throttle butterfly maby limiting flow and you would need to check the pressure on both sides of this to know.
from logan