installing. With mine, on high boost it would spike up to about 18-19psi and then bleed off to about 15-16psi. You can adjust the actuators; now that mine have been adjusted I am running 17psi on low boost (pump fuel) and 24-25psi on high boost (race fuel only) with no bleed off. I am not interested in going higher than that on those turbos so I do not know if they can support any more boost than that.