Subaru Tecnica International (STI) began as the motorsports division for Subaru in 1988. Amidst growing success in the World Rally Championship (WRC), the first STI model emerged in 1994, and its rally-proven performance has influenced the Subaru lineup ever since. The first Subaru Impreza WRX STI had 10 more horsepower than the standard WRX, stiffer suspension, and better brakes. In the 20 years since then, STI models have remained true to the first car’s winning formula of affordability, durability and high performance. Now that Subaru is poised to launch the new 2015 Subaru WRX STI, we’ve compiled a list of our favorite rally-bred STIs over the years to honor the occasion.
1998 Subaru Impreza 22B STIWidely known as the ultimate STI halo car, Subaru unleashed the Impreza 22B STI in 1998. It was intended to be a road-going version of the racer that won the 1997 FIA WRC title, Subaru’s third consecutive victory in the series. The year also intersected with the 40th anniversary of the Subaru brand.
The 22B featured a 2.2-liter, turbocharged four-cylinder engine modified from the regular 2.0-liter STI powertrain, with power ramped up to 280 hp and 267 lb-ft of torque. Subaru made the track wider with new wheels and tires, added flared fenders and rocker sill extensions to the bodywork, and increased the inclination of the rear-wing’s main plane by 17 degrees to produce more aerodynamic downforce. A twin-plate ceramic-disc clutch and close-ratio gears in the transmission made effective use of the increased power to help the car record a seriously swift 4.3-second sprint from 0-60 mph. Power peaked at a lofty 6000 rpm, and the engine would happily rev to its 7900-rpm redline.
Although the engine was perhaps the most distinctive feature of the 22B STI, Subaru did not overlook the car’s handling dynamics. Upgraded rack-and-pinion steering with a quicker ratio and a specially tuned suspension with Bilstein dampers were also part of the rally-based package. Bob Hall of Wheels magazine in Australia remarked that “nobody was quite ready for [the 22B’s] adhesion and cornering competence. In dynamics alone, the 22B comes very close to matching the classic Porsche 928 for chassis balance. It’s really that good.” High praise, indeed.
While the Impreza 22B STI’s performance set the formula for future generations of the WRX STI, the car’s looks were just as influential. The shape itself grew out of Prodrive’s Impreza RS, but the now-iconic livery of Sonic Blue Mica paint and 17-inch gold BBS wheels came from the original 555-sponsored Impreza rally cars of the mid-1990s. The trademark hood scoop and cherry-red STI badge continue to be visual signatures of the WRX STI even today. Subaru built just 424 units of the Impreza 22B STI, with 400 for Japan and the remainder for the export market.
2000 Subaru Impreza S201 STIIn April 2000, Subaru launched a 300-car run of a model inspired by the Electra One concept car. Called the S201 STI, the car set itself apart from the conventional WRX STI with a recalibrated engine computer, more turbo boost, a higher-capacity air-to-air intercooler and a larger, free-flowing exhaust, all of which pushed output to 300 hp.
The S201 STI also stood out in a crowd thanks to its bold body kit. A new front fascia included a wide lower grille opening and a much deeper bumper. New side skirts and a bi-level rear wing further transformed the exterior, while the car's cabin featured a titanium shift lever, aluminum pedals and blue interior trim. The STI boffins also fitted the car with a hood scoop, a limited-slip front differential, height-adjustable suspension, red brake calipers, and 17-inch forged-aluminum RAYS wheels.
Though sold only in small numbers, the S201 is quite distinctive and is a seriously memorable version of the WRX STI.
2001 Subaru Impreza WRX STIFollowing the debut of the second-generation Impreza, the Subaru Impreza WRX STI launched in Japan in late 2000. The so-called “New Age” generation of STI proved to be quite popular worldwide, thanks to its excellent driving dynamics, standout looks, and everyday usability. It would also be the first STI to make it to U.S. shores, although when it arrived here in 2004, it had an engine different from the one with which the car had been introduced in Japan.
The second-gen Subaru Impreza WRX STI continued to use a 2.0-liter turbocharged boxer-four engine, but it featured a significant bump in power. Upgrades to the 2.0-liter four-cylinder included lightweight hollow camshafts, variable valve timing, and electronic throttle control, which together helped increase power and response lower in the rpm range to compensate for turbo lag. To cope with the heat of increased performance, the STI contained an intercooler 30 percent larger than the unit used in the standard WRX, and a larger hood scoop directed air to it.
When all was said and done, the STI engine developed 280 horsepower and 274 lb-ft of torque, an impressive step above the 250 hp and 245 lb-ft by the engine of the standard WRX. In keeping with the car’s rally-bred performance, a close-ratio, six-speed gearbox was available as an option. A computer-controlled center differential varied torque distribution to the front and rear wheels, while Brembo brakes delivered fade-free stopping power.
When the U.S. model of this car arrived, it featured a 2.5-liter boxer engine that made a burly 300 hp and 300 lb-ft of torque. This gave it the power to prevail over the Mitsubishi Lancer Evo, which brought only 271 hp to the table with its 2.0-liter, turbocharged inline-four engine. Added power aside, the STI was also the better, more tractable day-to-day road car. As we said in a comparison test between the STI and a Mitsubishi Evo, “[The STI] is arguably more complete than any race-bred road car in history, and its owner needs to make very few sacrifices to enjoy it.”
2005 Subaru Impreza Prodrive RB320As the builders of Subaru’s competition cars for the FIA World Rally Championship, the engineers at Britain-based Prodrive knew their way around a fast Subie. These Prodrive-built Impreza racers eventually racked up three championships in the WRC with Colin McRae, Richard Burns, and Petter Solberg behind the wheel.
Prodrive has also been behind numerous hot Subaru production models over the years, and in 2005, it brought to market the RB320, a specially prepared Subaru Impreza WRX STI. The high-performance RB320 had a Prodrive-engineered package for the boxer four-cylinder that produced 320 hp, plus an upgraded chassis setup for a lower ride height with Eibach springs and Bilstein dampers. All of this made for a truly special STI, not to mention an aggressive appearance thanks to its mesh grille and 18-inch black wheels.
Only 320 units of this high-performance car were built, and all were sold in Britain. The RB designation honored Richard Burns, who died of brain cancer in 2005 just four years after winning the WRC championship with Subaru and Prodrive.
2011 Subaru Cosworth Impreza CS400Prodrive isn’t the only British racing company with links to Subaru, as Cosworth – the noted British builder of purebred racing engines – helped create the Cosworth Impreza CS400.
Cosworth had cast the aluminum blocks for Subaru’s rally engines, so it wasn’t too much of a stretch to prepare a total engine package. The turbocharged 2.5-liter boxer-four under the hood of the regular WRX STI was thoroughly upgraded with new crankshaft bearings, steel connecting rods, stout pistons with a lower compression ratio, new head gaskets and fortified head studs. These modifications helped the engine withstand increase boost from the new turbocharger, and the further addition of free-flowing intake and exhaust helped produce 395 hp and 398 lb-ft of torque, a bump of 90 hp and 103 lb-ft of torque over a U.S.-specification STI engine.
Cosworth also applied its magic touch to the WRX STI’s chassis. Eibach coil springs lowered the ride height by a half-inch, Bilstein dampers controlled the suspension action, and hard suspension bushings delivered sharper handling response. Heavy-duty, six-piston AP brake calipers produced stronger, crisper action from the front brake discs, and the 18-inch wheels were wrapped in super-sticky Michelin Pilot Sport 3 tires.
The Cosworth Impreza CS400 was never sold in North America, but Autocar got to sample the car in Britain. After the CS400 reached 100 km/hr (62 mph) in a scant 3.7 seconds and reached the end of a quarter-mile right on the back bumper of an Audi RS6, the magazine proclaimed this car to be “the fastest, most powerful and most expensive Subaru Impreza that’s ever been offered for sale in the UK.” Cosworth limited production to 75 cars -- but had it not, the $83,000 asking price would likely have limited sales anyway.