DETROIT MOTOR SHOW: Subaru WRX STI S209 arrives

The wraps have come off the Subaru WRX STI S209, a muscled-up special edition hot four that belts out more power, has a tough look and will be sold in very limited numbers in late 2019.

Okay, so it's not the new-generation 2020 Subaru WRX STI everyone's been waiting for, which likely won't arrive in Australia until 2021.

And of the 200 or so STI S209 units that will be built, none will be offered in Australia… but it shows that while STI may be hibernating, it's not dead and buried and continues the STI-built sports car tradition that started with the S201 18 years ago.

Technically the new model is an STI S209 and shouldn't even be called a Subaru because of all the fettling and modding that's gone on under the bonnet and inside the wheel arches.

According to car-maker, "…the STI S209 encompasses upgrades in power, handling, aerodynamics and driver engagement, and undergoes final assembly in Kiryu, Japan," at which point it is "homologated for the U.S. by STI". True story.

The Subaru EJ25 engine, a 2.5-litre four-cylinder boxer, now features a potent HKS turbo that hikes boost and with a few other addons increases output to around 254kW (340hp).

Torque? STI is not saying yet but expect it to be plenty more than the current WRX STI's 407Nm – possibly 500Nm of twist.

Other engine mods include forged pistons and con-rods to deal with the extra intensity of the bigger blower, a reworked intake system, larger fuel injectors, a high-flow fuel pump and even hand-polished headers and a new exhaust system. Oh yeah, the STI S209 will make some noise!

Naturally a six-speed manual is the only gearbox available, which transfers power to all four wheels.

STI has overhauled the chassis with a set of Bilstein shock absorbers, several rigidity enhancers (strut tower bars, stiff springs, bigger anti-roll bars), big six-piston Brembo front brakes with heavy-duty brake pads and a set of gold 19-inch BBS forged alloy wheels shod with ultra-fat 265/35 aspect ratio Dunlop tyres.

In other words, STI has done all the stuff to this car that serious tuners would do – only in this instance it keeps the warranty.

STI has done some work to the exterior too, with a 43mm wider body thanks to pumped wheel arches and an increase in its track by 15mm.

There's a motorsport-inspired rear wing designed to increase downforce over the rear axle and twin strakes ahead of the front wheels.

Inside the STI S209 are coloured-coded Recaro sports seats, a flat bottom suede steering wheel and interior décor that's beginning to show the car's age.

The Subaru WRX STI S209 could be one of the last special editions for the current generation car. Hang about for the 2019 Tokyo motor show, as we may get a taster of the next-generation Subaru WRX STI.