2019 Subaru STI S209 Debuts As STI’s Most Powerful Production Car Ever

U.S. Subaru buyers have suffered enough for the lack of track-bred WRX STI models such as the S207 and S208.

While those two performance versions were exclusive to Japan, the latest of the STI “S-line” models is now available exclusively to U.S. buyers. It’s called the STI S209 and it’s based on the WRX STI sedan.

To create the new model, Subaru Tecnica International has tuned various components of the stock WRX STI including engine and chassis, spicing everything up with exclusive exterior and interior parts.

For starters, the WRX STI’s EJ25 2.5-liter turbo engine now delivers 341 horsepower courtesy of many modifications headlined by an HKS turbocharger with a larger turbine and compressor, as well as an increased maximum boost pressure of 18.0 psi (16.2 psi for the WRX STI).

341 horsepower and 10 percent more mid-range torque at 3,600 rpm

The four-cylinder flat-four engine also features forged pistons and connecting rods that are both lighter and stronger. The list of extensive upgrades also includes a high-flow intake system with an intercooler water spray system (a nod to the 2004-07 WRX STI), larger fuel injectors, and an STI-tuned engine control module. High-performance mufflers and larger hand-polished stainless-steel exhaust tips (101 mm in diameter) round off the powertrain modifications.

As a result of all these changes, the power plant delivers 341 horsepower and 10 percent higher mid-range torque at 3,600 rpm. Subaru says that makes it the most powerful STI-badged production car ever. However, you might recall that Subaru released a 400 hp Impreza WRX STI CS400 in 2010 in the UK. Well, that one doesn’t count because it was a collaboration with Cosworth, not an STI-exclusive product like this one.

The STI S209 comes exclusively with a close-ratio six-speed manual transmission that directs power to the Symmetrical All-Wheel Drive system. The full-time AWD works with a Driver Controlled Center Differential (DCCD), Active Torque Vectoring and Multi-Mode Vehicle Dynamics Control.

Almost nothing was left untouched

STI also recalibrated the SI-Drive system which offers three modes: Intelligent (I), Sport (S), and Sport Sharp (S#). STI engineers recommend Sport for circuit driving and Sport Sharp for drag racing.

To safely manage the added power, the STI S209 wears 265/35 Dunlop SP Sport Maxx GT600A summer-only tires wrapped around lightweight 19 x 9-inch forged BBS alloy wheels. Developed exclusively for the S209 by Dunlop, the tires contribute to the car’s maximum lateral grip of over 1.0 g.

The wheels are housed by the bulging fenders that accommodate wider front/rear tracks (+0.6 in/15 mm front/rear). Stopping power is ensured by Brembo brakes featuring cross-drilled steel rotors and 6-piston mono-block front calipers and 2-piston mono-block rear calipers.

Subtle yet effective styling tweaks

For improved track performance, the suspension features specially developed Bilstein dampers, stiffened coil springs, a 20 mm (0.78 in) rear stabilizer bar and pillow-type bushings for the front/rear lateral links, among other solutions adopted from the WRX STI Nürburgring Challenge race car.

Styling-wise, the S209 brings distinctive elements such as the wide-body kit, front bumper canards, carbon-fiber roof panel and rear wing, as well as special S209 badges. Inside, the limited edition model features a D-shape, STI-badged steering wheel wrapped in Ultrasuede with silver stitching, Recaro front bucket seats with silver inserts, an S209 serial number badge on the center console, and S209 badges on the passenger-side dash and seat headrests.

STI will only build around 200 units of the S209, in two color combinations: WR Blue Pearl with gray wheels and Chrystal White Pearl with gold wheels. The car will debut in late 2019 with pricing to be announced closer to that moment.

*Update: Live images from Detroit added to the gallery