At the expense of sounding like a real idiot and being too lazy to read the other threads, I have an MBC problem.
I have been using an MBC similar in build and operation to the Joe P and Hallman for several years on two different cars. It has served me well on the WRX thus far.
Tonite, I installed a rather largish Garrett turbo and the boost controller doesn't seem to agree much with it. No matter how much I cranked down on the spring, I couldn't get more than wastegate boost or maybe a couple pounds over that. I pulled the hose off the WG actuator and voila, boost for days.
It's worth noting that I had to use a larger hose from the compressor outlet to the inlet of the MBC in order to accomodate the larger nipple on the compressor. Is this the cause for not making any boost?