Kendall Samuel and Mary Barker operate a Subaru performance company called Mechanical Advantage Racing in East Flat Rock, North Carolina. The company also races a 2000 Subaru Impreza 2.5 RS (GC8) they built to compete in road and time attack. The car is powered by a twin-turbo 2.3 L EJ-series flat-four producing 700 whp on E85 fuel. It features an IAG Stage 4 closed-deck EJ257 block, Callies 75 mm stroke crankshaft, Manley forged pistons, B25 heads, Brian Crower camshafts and springs. On each side of the motor sits a Garrett G25-550 turbocharger feeding charged air through an Audi B5 S4 intercooler. Power is sent to all four wheels through a XShift six-speed sequential transmission and R180 rear differential from a 2004 Subaru Impreza STi.
Source: @mechanical_advantage_racing and Garrett