STI also overhauls the suspension, adds bespoke Dunlop tires, and Brembo brakes.

Update: Live photos of the Subaru STI S209 are now in the gallery below. Subaru fans should also look for surprise appearances by the famous 22b, a 2004 WRX STI, and the company's latest rally car for American competition.

Photos: Chris Amos Photography

Subaru unveils its first-ever S-series vehicle in the United States with the launch of the STI S209 at the Detroit Auto Show. The hardcore model packs an estimated 341 horsepower (not an official number yet) from a tuned version of Subie's EJ25 2.5-liter turbocharged four-cylinder. If this sounds like something you want in your garage, then act immediately because the company is only bringing "around 200" of them into the United States.

Gallery: 2019 Subaru Impreza WRX STI S209

The S209 is not technically a Subaru model. Because of the extensive mechanical work necessary to create the model, the company actually homologates it as an STI in the United States, rather than a Subie.

STI thoroughly overhauls the engine to push the engine output so high. An HKS turbo replaces the standard part, and the upgraded unit packs a larger turbine and compressor. The setup also allows for maximum boost of 18 psi instead the normal 16.2 psi. Inside the powerplant, there are forged pistons and connecting rods that are stronger and reduce rotating mass. The intake system has revised ducting, and a control on the steering wheel activates the intercooler water spray. A high-flow fuel pump, larger injectors cope with the tuned engine's greater need for gasoline. Hand-polished headers provide a shine under the hood. To get rid of the bad air, a new exhaust has 17-percent less resistance and weighs just 4.1 pounds.

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The only available gearbox is a six-speed manual that routes to Subie's famous all-wheel-drive system. STI recalibrates the driving modes to reflect the drivetrain revisions, though. 

The S209 reflects its increased power on the outside through a heavily revised body kit. It adds wider fenders that broaden the body by 1.7 inches (43.2 millimeters) over a standard WRX STI. The extra width lets STI expand the front and rear track by 0.6 inches (15.2 mm). For even more grip, the performance division then covers the 19-inch BBS forged wheels with a set of 265/35 Dunlop GT600A summer-only tires. Dunlop specifically developed this rubber for the S209 so that the sedan was able to offer over 1.0 g of lateral grip.

As a further handling aid, STI gets serious about the S209's suspension. It rides on a set of Bilstein dampers, with stiffer springs and a 20-mm rear stabilizer bar. A flexible front strut tower bar and front/rear draw stiffeners add extra rigidity to the body. 

When the time eventually comes to slow down, the S209 has a set of Brembo brakes comprising cross-drilled rotors, 6-piston front calipers, two-piston rear calipers, and high-friction pads.

There are some very minor tweaks to the S209's interior. Drivers grip a flat-bottom steering wheel with Ultrasuede upholstery. Occupants in front sit in thickly bolstered Recaro seats with silver center inserts. 

The S209 will go on sale in late 2019. Subaru will announce the price closer to launch, although hardcore Subie fans will likely pay whatever the company will ask to own the most hardcore STI ever in the United States.

Source: Subaru

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SUBARU TECNICA INTERNATIONAL UNLEASHES MOST POWERFUL MODEL EVER WITH LIMITED-EDITION STI S209

Debuts at 2019 North American International Auto Show
First-ever STI-crafted S-line performance vehicle sold in the United States
Limited production run of around 200 units
Available exclusively in the U.S.
341-horsepower (est.) 2.5-liter SUBARU BOXER engine
Aggressive new look with wide fenders, front canards and rear wing
Performance-focused chassis with flexible strut tower bar and draw stiffeners
Exclusive 19 x 9-inch forged BBS® wheels with bespoke Dunlop® tires
Brembo® brakes with new high-friction pads
Available in two exterior colors: World Rally Blue Pearl and Crystal White Pearl

Detroit, MI – January 14, 2019 – Subaru Tecnica International (STI), a wholly owned subsidiary of Subaru Corporation, today introduced the limited-edition STI S209, the first-ever S- line STI product produced exclusively for the U.S. market. As an S-line product, the STI S209 encompasses upgrades in power, handling, aerodynamics and driver engagement, and 

undergoes final assembly in Kiryu, Japan, where it receives engine modifications and bodywork alterations that in total require it to be homologated for the U.S. by STI; thus, the S209 is considered the first “STI-built” Subaru sold in the U.S. The S209 carries on a high-performance tradition that dates to STI-built models that were exclusive to the Japanese domestic market – the 2000 S201 through the 2018 S208.

Designed with a focus on high-performance driving, the S209 draws inspiration and tech transfer from STI’s most formidable track machine – the WRX STI Nürburgring Challenge racecar, which won the SP3T class at the 2018 24 Hours of Nürburgring, marking the fifth time STI dominated the SP3T class at the grueling endurance race. The S209, like the Nürburgring Challenge racecar, wears an expanded wide-body exterior treatment, which extends the vehicle’s overall width to 72.4 inches, or 1.7 inches wider than a standard WRX STI. The bulging fenders accommodate wider front/rear tracks (+ 0.6 in front/rear) and 265/35 Dunlop GT600A summer-only tires wrapped around lightweight 19 x 9-inch forged BBS alloy wheels. The all-new tires, developed exclusively for the S209 by Dunlop, are a significant contributor to the car’s tenacious maximum lateral grip of over 1.0 g. Vents on the front fenders provide additional engine cooling, while vents on the rear fenders rectify air turbulence to reduce drag. Brembo brakes, with cross-drilled steel rotors and 6-piston monoblock front calipers and 2- piston monoblock rear calipers, provide stout stopping force, thanks in part to upgraded high- friction pads that deliver improved fade-resistance.

Underneath the S209’s broader body are specially developed Bilstein® dampers, stiffened coil springs, a 20mm rear stabilizer bar and pillow-type bushings for the front/rear lateral links. The S209 incorporates reinforcements to the front crossmember and rear subframes and, a la the Nürburgring racecar, a flexible front-strut tower bar and flexible front/rear draw stiffeners. The flexible tower bar, unlike a conventional rigid bar, is split and joined with a pillow ball joint in the center to be longitudinally mobile while helping laterally stiffen the body of the car. The result is optimum tire grip during lateral moments combined with compliant ride during longitudinal moments. Meanwhile, the draw stiffeners apply tension between the body and cross member to optimize chassis flex, improving stability when cornering and delivering better ride, handling and steering response. Other Nürburgring racecar tech that trickles down to the S209: front, rear and side under spoilers; front bumper canards; and carbon-fiber roof panel and rear wing.

A thoroughly reworked version of the legendary EJ25 2.5-liter turbocharged BOXER engine propels the S209. Featuring an STI turbocharger manufactured by HKS®, the EJ25 serves up an estimated 341 horsepower, thanks in part to a larger turbine and compressor (up 6 and 8 percent, respectively, compared to WRX STI) as well as maximum boost pressure that has been increased to 18.0 psi (16.2 psi for WRX STI). Proudly displaying an S209 serial number plate, the enhanced BOXER engine utilizes forged pistons and connecting rods that are both lighter and stronger. Midrange torque, too, gets a notable bump, up 10 percent at 3,600 rpm, delivering higher corner exit speeds when driving on track.

For ultimate driver engagement, the S209 comes exclusively with a close-ratio 6-speed manual transmission that routes power to a full-time Subaru Symmetrical All-Wheel Drive system with front/rear limited-slip differentials, a Driver Controlled Center Differential (DCCD), Active Torque Vectoring and Multi-Mode Vehicle Dynamics Control. A recalibrated SI-Drive system offers three modes: Intelligent (I) for improved fuel economy and smoother power control; Sport (S) for optimized power balance between response and control; and Sport Sharp (S#) for achieving the best acceleration times. STI engineers recommend Sport over Sport Sharp for circuit driving, as the less aggressive throttle map allows for greater driver control.

To feed more air to the EJ25, the S209 uses a high-flow intake system featuring a new intake duct, induction box with conical air filter, silicone turbo inlet duct and, a nod from the 2004-07 WRX STI, an intercooler water spray system that lowers intercooler temperature via manually operated steering-wheel paddles. More air demands more fuel, so the S209 receives a new high-flow fuel pump, larger fuel injectors and an STI-tuned engine control module. High- performance mufflers deliver 17-percent less airflow resistance and shed approximately 4.1 pounds. Finally, larger hand-polished stainless-steel exhaust tips – 101mm in diameter – deliver aggressive appearance and acoustics.

The S209 receives multiple tweaks to elevate it from other STI sedans. An STI badge replaces the traditional Subaru star cluster on the center of the D-shape steering wheel, which is wrapped in Ultrasuede® with silver stitching, a treatment that carries over to the lid of the center console storage box. An S209 serial number badge resides on the center console, and S209 badges adorn the passenger-side dash and the headrests of the Recaro® front bucket seats, which feature new silver-hued inserts. Outside, special S209 badges are affixed to the front grille and fenders as well as the rear decklid.

Only around 200 units of the STI S209 will be built, earmarked exclusively for the U.S. Available exterior color/BBS wheel combinations will be WR Blue Pearl/gray wheels and Crystal White Pearl/gold wheels. Pricing will be announced closer to the on-sale date in late 2019.