Detroit show: Subaru heats up WRX STI with S209
BY SPENCER LEECH | 15th Jan 2019
SUBARU has revealed a heavily modified version of its WRX STI sedan at the Detroit motor show, with the high-performance S209 grade set for a limited production run of around 200 units.
At this stage, Subaru Tecnica International’s (STI) ‘most powerful model ever’ will only be available to United States customers, however it will go through final assembly at is homeland in Kiryu, Japan.
While the S209 still uses the venerable EJ25 2.5-litre horizontally opposed turbo-petrol four-cylinder engine, STI engineers have heavily reworked the unit to produce 254kW of power, up from 221kW in the standard car.
To achieve this, Subaru employed a new HKS-built turbocharger which lifts maximum boost pressure from 16.2psi to 18.0psi, which is supported by forged pistons and connecting rods, a high-flow intake system, larger fuel injectors and a high-flow exhaust with 101mm tips.
Subaru says that mid-range torque has also been lifted, up 10 per cent at 3600rpm, but has not provided an exact output figure.
More grunt demands more brakes, and Subaru delivered with cross-drilled steel Brembo brakes with six-piston monoblock callipers up front, two-piston monoblock grabbers at the rear and upgraded high-friction pads to minimise brake fade.
Translating the power to the ground is a bespoke close-ratio six-speed manual transmission that routes power to Subaru’s famous Symmetrical all-wheel-drive system with front and rear limited-slip differentials.
The driveline is backed up by a Driver Controlled Center Differential (DCCD), Active Torque Vectoring and three revamped driving modes; Intelligent, Sport and Sport Sharp.
Handling has also been a big focus in developing the S209, with new Bilstein dampers on each corner, as well as stiffened coil springs, a 20mm rear anti-roll bar and new bushings for the front and rear lateral links.
The S209 also benefits from front crossmember and rear subframe reinforcements and a flexible front strut-bar, along with front, rear and side under spoilers, front bumper canards and a carbon-fibre roof panel and rear wing.
To accommodate a wider track with large 19x9.0-inch forged BBS alloy wheels on each corner, the S209 sports a wide-body kit that extends the vehicle’s width by 1.7-inches compared to the standard STI.
The bespoke hoops are shod in Dunlop SP Sport Maxx GT600A tyres measuring 265/35, which were specifically developed for the vehicle.
To reduce drag, the front fenders have been given large vents, which should also improve aerodynamics and filter more air to the engine for cooling.
All of this should equate to improved cornering stability, optimised chassis flex and improved feedback through the steering wheel.
The cabin has undergone a makeover too, with unique badging, an Ultrasuede trim pieces, Recaro front bucket seats and an S209 serial number badge adorning the centre console.
The Subaru STI S209 is earmarked exclusively for the North American market and will be available in Blue Pearl or Crystal White paint schemes.
Similar to its predecessors, the S209 takes inspiration from the WRX STI Nürburgring Challenge racecar that finished first-in-class at last-years 24 Hours of Nürburgring endurance race.
