As far as I know, Defined Autoworks is the first shop to build a 4-rotor Mazda rotary engine here in the US. They machine their own 4-piece eccentric shaft with 5 main bearings that allows the engine to spin up to 12,000 rpm. An Electromotive engine management computer controls four 2,200 cc injectors. Electromotive also supplies the two ignition computers that control the 12 coils of the triple spark plug ignition system. The video documents the assembly of the engine along with some shots of the sliding plate throttle bodies and variable length intake runners. Dyno tuning will come later with an eventual goal of 800 horsepower to the wheels.
Source: Defined Autoworks on YouTube via EngineLabs.com