This is wierd,
with an RB20 I get 17-18psi with the HKS 2530 before 4000rpm, I am pretty sure that it had 15psi @ 3500rpm ... definately had 17psi before 4000rpm, more like 3700rpm or earlier, wierd that you have the same response if not worse with an RB25 with the higher CR and capacity.
Anyone got ideas?
Evan