Turbo K20-swapped Subaru STi is Faster than Standard Modified Subaru

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Even though it is still being tuned, this K20-swap STi already took down its first victim.

A few weeks back, we discovered a crazy K-swapped Subaru STi that was beyond belief. The swap was being performed and documented by Kyle from BoostedBoiz on his friend, Emilio’s STi. Even though the Honda motor barely fit in the Subaru, the plan was to keep the car all-wheel drive, as stock looking as possible, while throwing on a turbo to max out the K20.

Fitting things were almost “straight forward,” if you can call it that. This older WRX STi model had a cable throttle, which worked far better for the K20’s throttle than a later car’s drive-by-wire setup. As well, some small tweaks to piping for the front-mount intercooler and the way things were routed allowed clearance to fit the original front bumper.

K-swap STi Subaru K20 turbo

Kyle and Emilio soon got to the point where they wanted to do some road testing, but the need to tune the ECU for the new turbo was needed. Obviously low-boost was initiated at first, and gradually was worked up from there. With things going well for low amounts of boost, some vacuum lines were adjusted and boost went up to 9 psi.

After a decent pull with 9 psi, Kyle and Emilio are elated. Kyle states, ‘9 psi? Wow! I was taking my time shifting from 3rd to 4th too because the clutch was feeling weird.’ It’s still a problem they were chasing due to a poorly fitting fastener, but regardless, the car is running strong. Strong enough to see how it gets on in a race with another STi. Hilariously, the K-swap puts on quite a show, gapping the other STi time after time. As it turns out the other Subaru was tuned, but still couldn’t quite keep up with all that turbocharged Honda power.

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Patrick Morgan is an instructor at Chicago's Autobahn Country Club and contributes to a number of Auto sites for Internet Brands, including MB World and 6SpeedOnline.

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