I currently have a MBC on my T-leg and with the controller turned all the way up, a cant run more than 7-8 psi. i even tried disconnecting the mbc to see if the turbo would just spool to the moon, with the same result, nothing over 8psi. the car has 145k on it, just put a dp on it and it has very little shaft play (vf-11) so uhhhhhh is my turbo shot?
Yeah, sounds like your running wastegate only. I'd first trace your hoses and make sure you have the proper routing.
I hope you have an intercooler on that thing, I wouldn't mess with a MBC without intercooling the beast.
Wastegate pressure on the VF-11 should be 5 psi, 8.9psi is the peak stock setting. I would check the spring in the MBC to make sure its holding pressure. Though there isnt much more to get out of the VF-11 much past 10-11psi, any more and your blowing hot air and banging off the fuel cut.