So i just went from a 7475 to a 7675 both have a .96ar and same everything, only change was the compressor wheel and antisurge housing. I run twin 44mm gates base boost on 18lb springs was 24psi, now with no other changes it has dropped to 18psi? Same boost curve on the logs though so peak boost is 4800rpm on both turbos. Switch to my old 30psi setting and now it is 28psi. I was expecting if anything boost pressure might go up i may have to add a spring to go up a bit and hit my goal of 40psi. I was able before to hit 40psi and hold it thoughts?