This Boosted Subaru Boxer Positively Sings At 12,000 Rpm

The EJ engine series has a very special place among Subaru enthusiasts. Introduced back in 1989 as a successor to the EA engines, it has a 16-valve flat-four layout with either a single- or double overhead camshaft arrangements, also known as SOHC and DOHC respectively. In factory form, naturally aspirated and turbocharged versions were available with power ranging from 96 horsepower (72 kilowatts) to 320 hp (239 kW).

Thankfully, there are still a lot of tuners around the world interested in optimizing and boosting the performance of the four-cylinder EJ motors. One of the leading Subaru performance specialists in Australia and the world, GotitRex, has recently presented its latest project based on the series, known as Betty.

After a heavy revision and the addition of a larger Garrett GTW3884 turbo that peaks at around 40 psi, the relatively compact engine now delivers a whopping 610 hp (454 kW) at the wheels and holds a flat power curve from 6,000 rpm onwards.. But what is even more impressing, the engine easily screams north of 10,000 rpm and you can see it almost hitting the 12,000 rpm mark at the video above.

he motor is still mounted on a standard 1994 Subaru Impreza LX chassis for test purposes, which means it is mated to a standard five-speed gearbox. While this setup is not expected to live in long term, currently the vehicle is able to hit around 140 miles per hour (225 kilometers per hour) in third gear alone. Like the folks over at Fullboost describe it, it pretty much feels like you are "inside a four-door motorbike."

With all that power from such a small engine and with the extremely high rev limiter, we can only be worried about its reliability. However, GotitRex says it has already done around 80 power runs on the dyno and some street and track tests, and the engine "has so far held up to everything thrown at it."