Prior to the release of the FA, the mainstay for performance Subaru builds was the iconic EJ powerplant. First seeing an introduction in 1989 on the Subaru Legacy, the EJ has seen a variety of configurations and output levels, with both naturally aspirated and turbocharged applications utilized over the years. The most famous of the EJ’s are those that came mounted in the nose of Subaru’s much-loved rally machine, the WRX and WRX STI. For the past two decades, tuners have tweaked this flat box of power for ever-greater levels of performance, and modern builders are pushing some serious horsepower these days. One such builder is Vince “Built” Griffin from Prime Motoring, who gave our friends over at Drive the lowdown on what it takes to turn the EJ into a total beast in this 19-minute, 32-second video.