Wow, interesting build. I'm glad to hear it is working. I wonder how this compares to Ray's dual charger system as far as efficiencies and throttle response. I'm guessing you still get the normal lag of a 16g, minimal as that is. When are you building boost?
I wonder if it would be practical to go with an even smaller first stage turbo like a 13b, or even T25, to start spooling that much sooner, say mid-to-low 2k rpm range. Also, what about swapping a 6cm housing onto the 16g for quicker spool? I'd see the trade-offs as potentially loosing some peak horsepower but stretching the torque band that much further down the rpm range. Would it be worth it? Just some things to explore. Again, great work and thanks for sharing.