Cosworth Engine Swap 2004 Subaru Impreza STi

• March 23, 2020
• Story By
  Cory Mader

It’s no secret that people get tired of things faster nowadays than they have in the past. Posts and reposts of photoshoots done with a brand new project revealed in Japan can be seen as fast as the ones and zeroes can bounce across the Pacific, and the same goes for posts from SEMA and the local Cars and Coffee event. That being said, there’s always been a group of owners that never tire of their car, instead choosing to refine it and improve it over time like a chef would a recipe that will be handed down to the next generation. It’s fair to say that after 13 years of ownership and countless changes here and there, John’s Subaru STI has found it’s own delectable niche—and it’s not going anywhere anytime soon.

After picking up this 2004 Impreza STI from its original owner with only 17,000 on the odometer, John ran it through the daily driver duties for 2 years before finally succumbing to the tuning bug. His first mods—an APS top mount intercooler, cold air intake, and 50/50 blow off valve—have all been traded out for new parts now, but we'll still start under the hood for this expansive parts list.

The most obvious thing that jumps out at a person underneath the Kaminari carbon fiber hood that is the APS cold air intake and Cosworth intake manifold finished in a rich red, matching the Enkei wheels (we’ll get to that part in a bit). A wire tuck, paint matched bay, and polished everything (valve covers, AC compressor and lines, alternator, strut braces, fluid tanks, crossover pipe, PCV breather tank, the list goes on) present on the Cosworth powerplant as if serving it all up on a blinding silver platter.

Said powerplant is an EJ257 2.5L Cosworth forged block fitted with Brian Crower 280 cams and Cosworth oversized valves, high-rev springs, and fuel rails delivering a healthy 580 hp to the wheels.

Tucked behind the piping is a hybrid ATP GT3582 turbo coupled to a Tial external wastegate and MVR blow-off valve that combine to make all the great noises you would expect from an engine like this.

Moving to the exterior, the red/silver colorway continues in full effect. A set of 18” x 9.5” Enkei RS05RRs wrapped in 255/35 Nitto NT05 tires adorn all four corners, perfect for car shows and canyon runs. In fact, this one build has brought home over 10 different best-of awards, the latest being ClassicCars.com’s Future Collector Car Show’s "Best in Show." To slow this scoob, John has a set of custom-engraved R1 Concepts STI logo rotors that are pinched by Brembo calipers. A set of Fortune Auto 500 coilovers with Swift springs keep the tires planted on the pavement.

Following the no-bolt-left-stock trend of this build, the exterior aesthetics have been massaged over the years as well. A Cusco GT front spoiler has been molded into the front bumper, framing up the JDM fog lights and leading back to the ChargeSpeed Type 2 side skirts.

Out back, JDM rear aprons have been molded into the bumper, alongside an APR carbon fiber rear diffuser and Tomei Expreme titanium catback exhaust.

A Carbon8 rear wing with an adjustable carbon fiber blade recalls the style of the (in)famous STI wing, while adding just a bit more angularity and adjustability.

Regarding the interior, it’s all-in on Alcantara, with a pair of Cusco/Bride Stradia II racing seats and red Cusco harnesses to bring the color from the outside in.

A full compliment of custom Alcantara pieces, parts from older STi models, and off-the-shelf parts come together to make a clean and concise cockpit feel.

There’s obviously way, way too much to touch on when it comes to John’s Subaru, but thankfully we’ve put together a full mod list to peruse along with the full gallery of photos below. With 13 years and over 100 different points of modifications, it’s safe to say this is one Subaru that’s been made to order.

TUNING MENU: 2004 Subaru Impreza STi

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