You guys kicked ass in this thread, I'll just add a couple details.
The 14b can only hold 25 psi to redline. Like a T25 dropping boost over 5k rpm. At this point efficiency becomes a non-issue, you are not even on the map at this point. And this is regardless of actualy pressure ratio. You are off the map to the right, at whatever boost you are at (dropping as rpm goes up). On pump gas and a sidemount, the most I could get away with was ~18 psi. On race gas I ran one into the 12s on the stock pump and injectors.
A required 2g pump will suffice. A 1g pump will not. A 190 would be recomended though
450s in a 2g will result in 90% IDC. Something that I rarely bring up though is that on 1Gs, base fuel pressure is lower, so the injectors flow less than what they are rated at. Injectors are almost always rated at 43 psi, a 2g has 42-43 psi base pressure, right on. A 1g however is ~38 psi. So 450s behave more like 417s. IDC in this case will go up to 97%. Still sufficient however. By the way, if anyone else is using the spreadsheet on my site, I have added this fuel pressure thing to the calculations, its now a user defineable field. Both base pressure, and rated injector pressure.
Keeping boost (therefore airflow) lower will allow you to run smaller fuel parts, but I like to have the pump and injectors be able to cover the MAX a turbo can put out, to protect the motor in the event of an overboost condition. More on that on my site too.
The spring pressure on the Mitsu turbos is 9-10 psi. So running a vac line from a boost source to the WG actuator will result in this boost pressure. It will only go higher if you get boost creep. And you will, with a larger exhaust, and no porting of the turbo. More on that on my site as well.
A boost controller shouldn't even be called a boost controller. The WGA is really what "controls" boost. We should be calling the MBC a Manual Boost Raiser
All it does is prevent the boost signal from reaching the WGA until a certain pressure, at which point the WGA does the actual boost control once again.