I was wondering if anyone here has the same issue like what i have...

I have stock turbo running with a hallman pro rx mbc.

The issue is that when I run my car at full throttle, my car will boost up to a max @ 16-17 PSI. and my mbc is maxxed out. When I turned down my mbc all the way down... my car will boost at 10psi. My car is tuned to run at 20-22psi but for some reason it is not allowing me to boost any higher than 16-17 psi... whats the issue?

I have searched the forum and couldnt find a solution to this problem that I have. any pointers would be nice.