The Subaru WRX is an all-wheel drive sport compact car manufactured by the Japanese automaker Subaru, originally based on the Impreza created for the World Rally Championship in 1992. Subaru claimed the name WRX stands for "World Rally eXperimental". Starting with the 2015 models, the WRX lineup has been split from the Impreza, with a different body style that is not offered as an optional hatchback/wagon, being introduced as the separate Levorg model. The car is known for its striking blue shade, with gold alloy wheels, because of a sponsorship with a Singaporean cigarette manufacturer.
STI In 1988, Subaru created Subaru Tecnica International (STi) as its motorsport division to develop and compete in the FIA World Rally Championship and other motorsports activities. Following the introduction of the first generation Impreza in November 1992 and the following year's debut of the Group A rally car into the WRC, an 'STi version' was made commercially available in January 1994 as a homologation model under FIA regulations. Thereafter, subsequent evolutions dubbed STi Version or simply STI were manufactured and sold alongside the Impreza model lineup initially in Japan only and later in selected world markets. As the STi or STI model was typically the highest spec of the Impreza, it has become popular with performance enthusiasts, tuners and amateur racers in many motorsports disciplines especially rallying and circuit driving.
Subaru has released many different models and versions including special limited editions of the WRX STI. However many of these versions were and are only available in the Japanese Domestic Market. Although the concept behind the STI model is taking a base model such as the Impreza or Legacy and further developing it for high performance, STI models fall mainly into 2 categories. The first is a fully developed and tested model with the purpose of homologating it for motorsports which is sold as a street legal road car. The second is a complete car pre-fitted from the factory with parts that are available from the STI catalogue and marketed as a 'Tuned by STI' model. Spin-off models with mainly cosmetic additions or alterations are also marketed usually in limited quantities.
Impreza-based models (1992–2014)
The first three generations of the WRX, sold until the 2015 model year, were based on standard Impreza platforms, and replaced the Subaru RX hatchback and saloon.
The initial first-generation WRX models were based on the Impreza saloon (GC chassis code). They were followed by wagons (GF) in 1993 and the first upgraded WRX STi version, introduced in 1994. Several limited edition first-generation coupés were offered in the late 1990s and early 2000s which were never sold in the US and are highly sought after by Subaru enthusiasts.
The second-generation WRX (GD/GG chassis codes for the saloon/wagon, respectively) was brought over to the United States domestic market for model year 2002, with the STI being brought over for model year 2004. The initial "bugeye" front end styling (2000) was superseded by the "blobeye" in 2004 and the "hawkeye" in 2006. Under an agreement between Fuji Heavy Industries and General Motors, Saab sold its own version of the WRX, marketed as the Saab 9-2X, for the 2005 and 2006 model years. The 9-2X was available in both a standard (Linear) and performance (Aero) package, the latter was essentially identical to the second-generation WRX wagon, mechanically.
The third-generation WRX were sold as chassis codes GE (saloon) and GH (hatchback, replacing the earlier wagon version) initially; the third-generation WRX STI was sold with a widened chassis and was available only as a widebody hatch (GR). For the 2011 model year, the third-generation WRX saloon and hatch were moved to the GV and GR wide-body chassis variants, respectively, and a widebody saloon version of the STI (GV) was marketed. The Impreza was redesigned and the fourth-generation was first marketed for model year 2012, making it a distinct model from the WRX, which continued on the third-generation GV/GR chassis until 2014 in most markets.
The fourth-generation WRX were given the VA chassis designation and marketed as a separate model from the Impreza starting in 2015.
WRC The Subaru Impreza WRC is a World Rally Car based on the Subaru WRX. It was used by Subaru World Rally Team, Subaru's factory team, and replaced the Subaru Legacy RS in 1993. The car was debuted at 1993 Rally Finland and won a total of six world rally titles, including three consecutive manufacturers' titles and three drivers' titles.
Group A Impreza GC, 1993–1996
For 1993, Prodrive recognized that a smaller, nimbler car would make a better platform for a rally car, and work on a Group A Impreza rally car began. It was 160 mm shorter in overall length with a 60 mm shorter wheelbase, as well as having a more neutral front/rear weight ratio. It also featured active differentials, a first for a rally car. At the 1000 Lakes Rally, Subaru debuted their new Prodrive developed Impreza derived Group A rally car, driven by Vatanen and Alén. Vatanen drove the car to second place on its debut.
In 1994, the Subaru team switched from Michelin to Pirelli tires.
For the 1995 season, the FIA mandated more restrictive air intakes in an effort to slow the cars down. Subaru countered this by introducing a new boxer engine with revised camshafts and a different compression ratio.
World Rally Car Impreza GC, 1997–2001
For 1997, the FIA replaced the Group A formula with a new formula called World Rally Car. This gave teams greater latitude in design and materials including vehicle width, suspension geometry, aerodynamics, intercooler capacity and engine modifications. This led to a totally redesigned car, the WRC97, featuring modified camshafts, cylinder ports and combustion chambers. The new body had two doors. The width of the car increased to 1,770 mm (69.9 in) with a revised suspension geometry. Power increased to @ 5500 rpm, and torque was now .
The Impreza WRC98 was an evolution of the earlier WRC97, with computer controlled active differentials in the front, rear, and centre, and an electronic throttle. Mechanical failures were common and took the team out of contention for the title.
The WRC99, introduced at the first round of the championship, featured an electronically controlled, hydraulically actuated semi-automatic transmission with a drive-by-wire throttle, allowing the cars to be shifted with steering wheel mounted paddles, similar to F1 cars.Subaru World Rally Team This allowed the driver to shift gears faster, and reduced the chance of dog gear wear. Due to technical difficulties, the team struggled until the season's 7th round in Argentina. However, the car helped prove much of the technology seen on later cars. Subaru was the first rally team to implement this technology, which has been used on all WRC cars until it was forbidden by the 2011 championship rules.
Although the WRC2000 looked almost identical to the WRC99, underneath the sheet metal, its execution was radically different. Developed by Prodrive engineer Christian Loriaux, the team used the lessons learned from the WRC99 and applied them in the WRC2000's 10-month development, in which over 80% of the car's mechanical and electronic components were redesigned. The car debuted, and drove to victory, at the fourth event of the season, Rally Portugal.
World Rally Car Impreza GD, 2001–2008
The WRC2001 featured an entirely new look, based on the GD chassis Impreza WRX. The new body had four doors (instead of two), and featured revised aerodynamics, improved weight distribution, and a lower centre of gravity. However, all the mechanical development from the previous year, including the engine, suspension, and drivetrain remained, with subtle refinements.
The WRC2002 was introduced at Corsica, and looked largely the same as the previous year's car. However, development of the car continued throughout the season. Improvements were made to the driveshaft, transmission housing, and steering column, as well as to the turbo-charger and manifold, which was changed from a 4–2–1 configuration to a 4–1 configuration. Savings found in modified brackets, wiring, and glass reduced weight by .
The WRC2003 was introduced at the 2003 Rallye Monte Carlo. It featured a revised look based on the updated Impreza production car introduced the previous year, with the "bugeye" headlamps replaced by the "blobeye" lamps. Technical improvements were made to the turbocharger and engine, aiming to increase torque at lower RPMs allowing greater driveability. The car's body shell was made both lighter and stiffer. Throughout the year modifications were made to the car's suspension.
The WRC2004 did not feature many cosmetic changes from the previous year's car, but did have refinements in the engine and body panels. It was introduced at Rally Mexico. A revised gearbox was introduced halfway through the season.
The WRC2005 was introduced following 12 months of joint development by Subaru and Prodrive, on 11 March 2005 at Rally Mexico. Its re-styled bodyshell was stiffer, and 30 mm wider to allow a wider track. The car featured more composite body panels, including front and rear wheel arches and bumpers in order to decrease weight. Engine enhancements included a lightened flywheel and revised IHI turbocharger. Revised water injection and fuel injection systems were also introduced.
The WRC2006 received the production car's second facelift with the "hawk eye" headlamps. It had several mechanical changes from the previous year's car due to rule changes which banned active differentials as well as water injection, as well as mandating that teams must re-use cars and engines on selected ‘pairs’ of events. Due to the rule changes, the car was introduced on the first round of the season.
The WRC2007, a revised version of the earlier year's car, was introduced at the fourth round of the championship, Rally México. It featured new dampers, a different radiator and intercooler arrangement, as well as improved weight distribution, suspension geometry and differential set-ups. It was considered to be underachieving compared to the newly introduced 2007 Focus WRC and the all-new Citroen C4 WRC. The car suffered from extensive handling problems, resulting in Subaru withdrawing from Rally Finland on the second day of the rally.
Each transmission in the WRC2007 takes 85 hours to build, and costs over £75,000. The front and rear differentials are similar while the centre differential is unique. Each takes around 16 hours to build and costs about £20,000. The cases for the transmission and differentials are constructed from magnesium to reduce weight. Filled with oil, the transmission weighs 95 kg, and a differential weighs 25 kg. The car's engine, transmission and differential are individually oil sealed, so that they can be removed and replaced without fluid loss. This also helps the team replace the components in 10–12 minutes. The transmission's lubrication system has a 4.5 litre capacity and includes an oil pump to help control differential temperatures, which usually operate around 100C. The transmission retains the roadgoing Impreza's H pattern but utilizes a hydraulically actuated and electronically controlled semi-automatic gearshift. The hydraulic gear shift system operates at a pressure of , allowing gear shifts to be completed in less than 0.1 seconds.
World Rally Car Impreza GR, 2008