To help control boost pressure, I installed a Turbosmart e-Boost 2 electronic boost controller. It allows for gear based boost mapping and controls an auxiliary output to the water injection. I mounted it under the seat next to the Alien Motion battery with the auxiliary relays mounted below.
I also designed a gear switch assembly. The setup uses two micro switches on the gear shift shaft connected to the Turbosmart e-Boost 2. Shifting up grounds one circuit and tells the controller to switch up to the next boost map; shifting down grounds the other circuit and tells the controller to switch down to a lower boost map. I can program a unique boost map for each gear. I also wired the down shift switch into the neutral light circuit as a fail safe setup, so that the neutral light will flash in between each down shift, and if it does not, I know the micro switch has failed. That way I am not getting surprised by a high boost map in a low gear. The location of the micro switches actuate them only after a complete gear change, preventing any false shifts from sending a signal to the controller.