Subaru Impreza WRX Specifications
The Subaru Impreza WRX is a turbocharged version of the Subaru Impreza, an all-wheel drive, four-door passenger vehicle. It is available as a sedan and wagon, or in the third generation as hatchback.
Originally introduced in 1992 in Japan, then shortly afterward in New Zealand, Australia and Europe, the WRX features a turbocharged 2.0L (then later a 2.5L) version of Subaru’s EJ series flat-4 Boxer engine. Compared to the base Impreza, the WRX also has wider wheels with lower profile tires, larger brakes, and firmer, higher-quality suspension components.
The Impreza WRX was first sold in North America in 2001 as a 2002 model year.
GC chassis (1992–2000)
There have been seven noted versions of the WRX. The STI versions were marketed with consecutive numbers. Another way to determine the version of a WRX was to look at the chassis code. All WRX sold between 1992 and 2000 have the beginning chassis code of GC8 sedan or GF8 hatchback; this is followed by a letter from A to G.
|Body style||2-door coupe
|Wheelbase||2,520 mm (99 in)|
|Length||4,375 mm (172 in)|
|Width||1,705 mm (67 in)|
|Height||1,410 mm (56 in)|
The WRX debuted in November 1992 with 240 PS (176.5 kW; 236.7 hp) at 6000 rpm with 31 kg·m (300 N·m; 220 lb·ft) at 5000 rpm. Both front and rear brake rotors were ventilated disks. The vehicle had a curb weight of 1,220 kg (2,690 lb). The center differential was a viscous coupling type. The rear LSD was a viscous type. The WRX Type RA (marketing has made usage of the RA acronym in various ways; Record Attempt is the current usage. “R = Racing, A = Group A, the FIA racing class the WRX Impreza competes in” has also been confirmed by Subaru of Japan; the correspondence can be seen on the discussion board for this article) is a stripped down version of the WRX for people to purchase for motorsports and tuning. It does not have many “creature comforts” such as air-conditioning or a radio. The car also lacks anti-lock brakes. The WRX Type RA has had a weight reduction to 1,170 kg (2,579 lb), and uses a closer ratio gearbox. The WRX Type RA steering wheel is a 3 spoke leather-wrapped wheel from Nardi. The sti ra version was the road version of the wrx
In October, 1993, Subaru introduced the 1994MY WRX which produced 240 PS (176.5 kW; 236.7 hp) at 6500 rpm with 28.5 kg·m (279 N·m; 206 lb·ft) at 5000 rpm. The wheels remained the same size. The rear rotors were substituted from ventilated disk to solid disk. The vehicle gained 30 kg (66 lb) to a total curb weight of 1,250 kg (2,756 lb). October 1993 was also the start of production of the hatchback version, with 220 PS (162 kW; 217 hp).
It is also debated whether or not it was just the GF8 hatchback received the 220 PS (161.8 kW; 217.0 hp) engine or if the 1994 WRX received it as well. Previously this entry stated the WRX engine was downgraded to 220 PS (161.8 kW; 217.0 bhp).
WRX SA Model (which had the totally different chassis which was designed by Aiden Humphries)
built May 1993 until Sep 1994 (GF8-B only) came as auto and manual. with or without air-conditioning on both models. The engine and ECU was the same as the normal wrx hatchback (manual or auto models) had colour coded mirrors but black door handles came in colours deep blue (331), deep green (307), flamy red (936), light silver (406), black mica (47a), feather white (230)
In November 1994, the WRX had a power increase to 260 PS (191.2 kW; 256.4 hp) at 6500 rpm with 31.5 kg·m (309 N·m; 228 lb·ft) at 5000 rpm. The wheel diameters were increased to 16 inches (410 mm) and brake rotors were both changed to ventilated disks. With these modifications, the curb weight decreased to 1,230 kg (2,712 lb). In Japan, the WRX was also offered in the Sport hatchback and was called the Impreza Gravel Express but was discontinued due to very limited sales, and replaced by the Subaru Forester.
The 1996 WRX debuted in January 1996. The WRX design received minimal mechanical changes, but a WRX V-Limited Edition was introduced to celebrate the success of the Impreza WRC car in the FIA WRC. It was mechanically the same to the WRX but had a curb weight nudge to 1,240 kg (2,734 lb). The V-limited cars are painted in World Rally Blue.
In September 1996, the WRX was updated with new styling. The 1997 WRX now has a power rating of 280 PS (205.9 kW; 276.2 hp) at 6500 rpm with 33.5 kg·m (329 N·m; 242 lb·ft) at 4000 rpm (280 PS (205.9 kW; 276.2 hp) at 6500 rpm with 35.9 kg·m (352 N·m; 260 lb·ft) 4000 rpm for the hatchback version). The car now weighs 1,250 kg (2,756 lb).
Produced from 9/1998 through 9/1999. Mechanically this was virtually the same as its predecessor. The torque was increased a little from 242 to 250 lb·ft (328 to 340 N·m) at 4000 rpm. The weight also continues to increase and is set at 2,800 lb (1,300 kg).
The last version of the WRX is introduced on September 1999. There is no change in the mechanical specifications. Added features are newly-designed alloy wheels, color-coded mirrors and door handles, remote central locking, intermittent wipers with a timer and map lights. Red Mica had replaced Bright Red..
The WRX was introduced as the Impreza GT (Europe), Turbo 2000(UK). It came with 208 hp (155 kW; 211 PS).
The Subaru Impreza WRX GT’s(Turbo 2000) interior and face have been updated to leather.
UK-spec Special Variants
Subaru imported six Type RS’s, the development car that led to the stripped-out Type RA. For UK car certification reasons they were registered as 1.8GL’s despite having big turbos attached to 2 litre engines. Three cars went to Prodrive; three were retained by Subaru UK and were subsequently sold.
Series McRae UK Version (June 1995)
To commemorate Colin McRae’s success in the international rally scene and his 1994 RAC win in particular, Subaru released 200 limited edition ‘Series McRae’ cars, prepared by Prodrive. These vehicles were finished in a very limited ‘Rally Blue’ mica colour scheme, sported gold 6.5″x16″ Speedline ‘Safari’ alloy wheels, McRae decals, individual numbered badging from 1–201 (car no. 13 was never built since the number 13 is considered unlucky), and a factory-fitted electric tilt/slide sunroof. Recaro seats were fitted in the front, and the rear seats and side panels were retrimmed in the same Le Mans/Avus material.
On the road price was £22,999.
McRae Owners Club
Catalunya (March 1997)
200 cars (again excluding car number 13) in Black Mica with red flecks riding on gold alloy wheels were made to celebrate winning Subaru’s second WRC manufacturer’s title at the Rally of Spain (Catalunya). The car was sold for £21,610. A similar car in Blue Mica was sold in Italy.
Turbo Terzo (April 1998)
333 Cars In Blue Mica And Gold Alloys, to celebrate their manufacturer’s WRC title. It cost £22,995.
Subaru won a hat-trick of manufacturer championships and celebrated once again by releasing a new special edition Impreza. The Subaru Impreza Terzo (Italian for 3rd). Only 333 Subaru Impreza Terzos were made, as a mark of the three championships won with the Subaru Impreza.
Subaru Impreza RB5
To celebrate the return of British driver Richard Burns to the rally team in car number 5, a limited edition of 444 cars in “Steel Blue” (aka Cool Grey) was created. The basic £24,995 model had little more than cosmetic differences, but most had the WR Sport Performance Pack, an option consisting of a new ECU and exhaust for 240 PS (177 kW; 237 hp) and 350 N·m (258 lb·ft) torque. The price for the higher spec car was £27,495. . There was also an optional Prodrivesuspension pack that cost extra again. Standard Impreza Turbos could be fitted with the suspension pack and cosmetics to create a ‘Prodrive WR Sport’.
Prodrive WR Sport (1999)
The standard Impreza Turbo 2000 was tuned and partly restyled by Prodrive. It featured a Prodrive – exclusive interior, a Prodrive suspension upgrade, Prodrive bodykit and wheels, WR Sport decals and an optional ECU upgrade for increased performance. It sold for £30000.00
P1 (March 2000)
Prodrive upgraded 1000 Imprezas for a price of £31500.00
GD chassis (2000–2007)
|Body style||4-door sedan
5-door station wagon
|Engine||2.0L 227 hp H4 (2001–05)
2.5L 230 hp H4 (2006–07)
|Wheelbase||99.4 in (2,525 mm)|
|Length||173.4 in (4,404 mm) (2002–03)
173.8 in (4,415 mm) (2004–05)
175.8 in (4,465 mm) (2006–07)
|Width||68.1 in (1,730 mm) (2002–03 & 2006–07 Sedan)
68.5 in (1,740 mm) (2004–05 Sedan)
66.7 in (1,694 mm) (Wagon)
|Height||56.7 in (1,440 mm) (Sedan)
58.5 in (1,486 mm) (2001–05 Wagon)
57.7 in (1,466 mm) (2006–07 Wagon)
Subaru Impreza WRX STi
In December 2000, the Impreza model underwent a long awaited completed full model change. Body dimensions increased by 45mm in length, 40mm in width for the sedan and 25mm in height. The wheel base however increased only by 5mm from 2520mm to 2525mm. Interestingly, the wagon version’s width increased by 5mm to 1695mm because in Japan this is the limit for a ’5′ number vehicle classification while the sedan went into the ’3′ number class mainly to increase the width of the track for added stability as Subaru intended to homologate the GD chassis for WRC. Other main improvements to the chassis was a 120% increase in torsional rigidity. Mainly due to revisions in front subframe design. The suspension retained its basic McPherson strut in the front and rear although the geometry was changed. The GDA WRX model also retained the 5-speed manual transmission gearbox design from the GC8. Subaru later released a new 6-speed gearbox for the STi model GDB which was significantly stronger.
The GD chassis along with the WRX and STi underwent two styling changes in its life cycle. The nickname “bug eye” or “round eye” as it was called in Japan from applied A & B. Initially this design proved to be rather unpopular which prompted a more conventional but modern design in the applied C,D & E models. The facelift design was penned by no other than Peter Stevens of Prodrive who was responsible for the 1997 Impreza WRC car. This model is nicknamed “teardrop eye”. Applied F & G saw the application of FHI’s corporate face for Subaru at the time with the also unpopular “jet intake and wings” grille which first debuted on the Subaru R1 & R2 kei car, along with new headlights design nicknamed “hawk eye”. FHI chose this style to pay homage to their aircraft manufacturing roots, the Nakajima Aircraft Company
Japan Domestic Model
Applied A (2000)
August 2000 brings the 2001 WRX NB sedan. It has an EJ205 with AVCS coupled with an IHI TD04L turbocharger. The engine produces 250 PS (184 kW) at 6000 rpm with 34 kg·m (246 ft·lbf, 333 N·m) at 3600 rpm. The wheels are 16-inch (410 mm) in diameter. The car uses 2 pot/1 pot front and rear brakes. The front brake rotors are ventilated while the rear are solid disks. It has a Torsen rear LSD and a 4.44 final drive ratio. The transmission has close-ratio gears unique to Subaru of Japan at that point in time. The car has a curb weight of 1,340 kg (2,954 lb).
Applied B (2001)
The 2002MY WRX NB sedan debuts on September 2001. The mechanical specifications are similar to the previous year’s model but the curb weight has been increased to 1,350 kg (2,976 lb).
Applied C (2002)
The WRX NB-R sedan is released on November 2002. The power and torque ratings are the same as the previous year. The wheel diameters are increased to 17″ in size. The rear brake rotor is changed to a ventilated disk, leaving the car to use only ventilated disks for braking. The car has 4 pot/2 pot front and rear brakes. The rear wing is on wing risers. The car now weighs 1,361 kg (3,000 lb).
Applied D (2003)
The WRX line receives a body exterior update and an improved transmission
Applied E (2004)
The WRX WR-limited is introduced. The car receives an STI spoiler and an STI front chin. There is a WR-stickered titanium shift knob. The wheels are changed for STI, gold-colored Rays-sourced wheels.
Applied F (2005)
The WRX has an option to receive the same spoiler as the WRX STI. The WRX has a viscous rear LSD now.
Applied G (2007)
The car is mechanically the same as the previous Japan-spec revision.
US Domestic Market
Applied A (2000)
WRX’s initial release date 2000
Applied B (2001)
North America receives its first Impreza WRX models. They are equipped with an EJ205 engine rated at 227 hp (169 kW) at 6000 rpm with 217 lb·ft (294 N·m) at 4000 rpm. Unlike the Japanese EJ205, the US-spec engine uses a Mitsubishi TD04-13T turbocharger unit. In stock form, it reaches a peak 13.6 psi (0.9 bar) of boost. The seats are the same as the basic J-spec Impreza. The wheels are cast 16″ x 6.5″ version of the J-spec WRX NB wheels while the brakes are 2-piston/1-piston front and rear with the front rotors being ventilated disks. 2002 WRXs came with brake duct plates that guided the air in the front bumper vent to the wheel well. The gear ratios are the standard export models, but the final drive is a 3.9:1 ratio. The rear LSD is a viscous coupling type. The steering rack has a ratio of 16.5:1. The 4 gear electronic automatic transmission (4EAT) WRXs have a Variable Torque Distribution AWD system instead of the conventional viscous coupling center differential. VTD employs an electronically controlled hydraulic transfer clutch and a planetary gear center differential to distribute power in a 45:55 split between the front and rear axles under normal circumstances. The VTD system uses multiple sensors to measure front and rear driveshaft speeds, throttle position and gear selection. Then it actively transfers power accordingly between the front and rear wheels for optimum traction and handling. The WRX weighs 3,085 lb (1,399 kg).
Applied C (2002–2003)
There are few changes from applied B. The gears are changed to RA-width gears (1 mm increase in size) to increase durability of the transmission. There is also a valve that prevents “drop-clutch” starts in an effort to reduce the number of shattered gear boxes from abusive AWD launching. The ignition ring is now illuminated with green lighting. Early 2002 WRXs had brake duct plates. At the end of calendar year 2002, the brake duct plates were no longer equipped on the WRXs. A shorter metal fuel pipe and longer connector hose were implemented under the intake manifold to avoid fuel leaks at freezing temperatures.
Applied D (2004)
2004–2005 Subaru Impreza WRX wagon (US)
The WRX received the same Peter Stevens-designed face lift that rest of the Imprezas received. The WRX uses the same contoured seats as the 2004 US-spec WRX STI. The WRX is equipped with multi-phase valve struts to improve ride quality while retaining good handling. The tachometer was moved to center, and the speedometer was moved to the right.
Applied E (2005)
The WRX received an updated interior, body color rocker panels, black painted headlamp bezels, and wheels that were previously seen on the base US-spec Legacy and a single-port exhaust. Some WRX models have an STI hood scoop that is much larger than other WRX scoops. The suspension has also received a few small updates to make handling more efficient compared to the 2004 model. Cassette players in the stereo system were no longer offered.
Note: Saab released its 9-2X Aero, from its 9-2X line, which is essentially a re-skinned Impreza WRX Wagon of the same model year. It is manufactured by Fuji Heavy Industries, Ltd.
Applied F (2006)
The biggest change was the 2.5-liter turbocharged intercooled EJ255 engine, producing 230 hp (172 kW) at 5600 rpm. It replaced the 2.0-liter EJ205 engine used since the WRX model’s introduction. The larger-displacement engine produced 235 lb·ft (319 N·m) of peak torque at 3,600 rpm, compared to 217 lb·ft (294 N·m) at 4,000 rpm for the previous WRX. Performance was improved in all speed ranges, with greater emphasis on low-end and mid-range torque. The 2.5-liter WRX engine shared architecture and technology with the WRX STI engine, including Subaru Active Valve Control System (AVCS) variable valve timing and an Electronic Throttle Control system. The turbocharger remained the same unit as on the 2002-2005MY US-spec WRXs, but peaked at 14.8 psi (1.0 bar) of boost. The first gear in the transmission received dual-ring synchros to improve downshifts from 2nd to 1st and reduce notchiness.
2006 Impreza WRX models gained some chassis and braking system enhancements. On sedan models, aluminum front suspension lower A-arms reduced unsprung weight. (The rear suspension gained forward aluminum lateral links in the 2005 model year.) The steering rack was updated for improved steering feel and the steering rack ratio was changed to 15.0:1. On all WRX models, 7-spoke 17 x 7-inch (180 mm) aluminum-alloy wheels replaced the previous 5 spoke 16 x 6.5-inch (170 mm) wheels. Tires were 215/45ZR17 versus 205/55R16 before. The more powerful brake system employed 11.5 in (292 mm) vented front discs and four-piston calipers instead of the previous versions two-piston calipers. The rear brakes were 11.3 in (287 mm) ventilated discs replacing the previous 10.3 in (262 mm) solid discs, and two-piston calipers replacing single-piston calipers. The calipers are painted red with the SUBARU name in white overlain.
Applied G (2007)
Ikuo Mori takes the place of Kyoji Takenaka as President and CEO of Fuji Heavy Industries.
As a cost-cutting effort, the WRX has its aluminum suspension reverted to steel-cast pieces. The WRX and Limited trim levels receive an auxiliary audio port next to the cigarette lighter and MP3 CD playback.
Depending on the country, one may be able to buy either Oceania-spec, Europe-spec or US-spec WRXs. There are no models unique to the Asian market outside Japan.
WRX UK300 (2001)
Subaru produced 300 examples of the UK300 to celebrate the rallying success in the UK from the previous years. It featured 18-inch-Prodrive-OZ-wheels in gold, Pirelli Rosso P Zero Tyres, a blue Alcantara Interior or an blue leather option, UK300 floor mats, UK300 headlights, UK300 exclusive front and rear spoilers and UK300 decals.
WRX 300 (2005)
300 vehicles limited to the UK market were sold with Blue Mica exterior paint, 17″ gold alloy wheels with 215/45 tyres, Subaru World Rally Team branded front bucket seats, a 5-speed manual transmission and the Prodrive Performance Package (PPP) all as standard equipment. The Performance Package increased power to 265 PS (195 kW; 261 hp) and 348 N·m (257 lb·ft) torque and equipped the car with a 0–60 time of 4.8 seconds and a maximum speed of 151 mph (243 km/h). 12 months’ free subscription to RAC Trackstar was included in the basic on the road price of £21495.00 (approx. $31800). Considering that the total on the road price of the standard non-limited edition Prodrive Performance Pack equipped Impreza WRX was £21900.00, the WRX 300 represented very good value for money. Optional extras included a 18″ P-FF7 wheel and tyre package, a Prodrive brake upgrade (front brakes only), a sports suspension upgrade and a special edition rear spoiler.
The RB320 was available only in Obsidian Black, also features bespoke 18 inch alloy wheels and specially developed Prodrive suspension comprising Bilstein dampers, a sports spring kit with revised rear anti-roll bar and a ride height lowered by 30 mm (1.2 in) at the front and 10 mm (0.4 in) at the rear.
Also standard was a chrome mesh front grille, front lip spoiler, quickshift gearchange, side sill plates and RB320-branded gear knob, carpet mats and exclusive exterior badging. Each owner will also receive an individually numbered black alloy tax disc holder.
The Prodrive Performance Pack (PPP) boosts power to 320 PS (235 kW; 316 hp) at 6,000 rpm with torque leaping to 332 lb·ft (450 N·m) at 3,700 rpm. This reduces the 0–60 mph time to 4.8 seconds with a 0–100 mph time of 12.2 seconds.
Subaru produced only 400 cars; 300 4dr saloon versions and 100 5dr hatchback models. The GB270 was available in either WR Blue Mica (4dr) or Urban Grey Metallic (5dr). The name was derived from the 2.5 litre turbocharged engine which produced 270 PS (199 kW; 266 hp) and 420 N·m (310 lb·ft) of torque. These upgrades meant a 0 to 60 mph (97 km/h) in 4.9 seconds was possible and 146 mph (235 km/h) top speed could be achieved. The top speed of the GB270 was slightly lower than that of other Imprezas because it featured a Prodrive Quickshift 5-speed gearbox which offered faster gear shifts compared to the standard 6-speed gearbox.
Prodrive fitted their upgraded suspension system, lowering height of the car by 30 mm (1 in) at front and 10 mm (0 in) at rear.
A Prodrive anti-roll bar, Prodrive polished stainless-steel mesh front grille, a set of bespoke 18″ Prodrive alloy wheels – Silver on 4dr, Black on 5dr were included in the £22,995.00 on the road price.
Rev. A (2001)
The WRX has an EJ205 rated at 218 PS (160 kW; 215 hp) @ 6000 rpms. It carries 17″ x 7″ wheels and has 4-piston/2-piston front and rear brakes with ventilated disk rotors all around.
Rev. B (2002)
Due to complaints of slower acceleration in comparison to the GC-chassis WRX, the gear ratios and diff ratio are changed to the same specifications as the Japanese domestic market WRX to improve overtaking and in gear acceleration. The result is near identical first and second gear ratios to the GC, but with a noticeably shorter third, fourth and fifth gear.
Also added was a Suretrac limited slip rear differential. Japanese engineers claimed that drive would still be directed to the gripping wheel even if the other wheel was off the ground.
Rev. D (2004)
The WRX received the same Peter Stevens-designed facelift that rest of the Imprezas received. During 2005 a limited edition Subaru Impreza WRX WRP10 was produced, but limited to 200 vehicles. The Australian market models received an engine upgrade to 168 kW and 300Nm via a compression ratio increase to 9.0:1 and the addition of variable valve timing on the intake camshafts.
Oceania-spec Special Variants
Subaru Impreza WRX WRP10 (2005)
See: Subaru Impreza WRX WRP10
The Prodrive Performance Pack (PPP) is an official accessory for UK GD-chassis WRX’s. It evolved from the WR Sport pack fitted to some RB5s. The 2007 version costs £1700 including VAT and fitting, raising power output from 230 PS (169 kW; 227 hp) to 270 PS (199 kW; 266 hp) and torque to 420 N·m (310 lb·ft).
Rev. A (2001)
The WRX has an EJ205 rated at 218 PS (160 kW) @ 6000 rpms. It carries 17″ x 7″ wheels and has 4-piston/2-piston front and rear brakes.
Rev. B (2002)
Due to complaints of the slower acceleration of the GD-chassis WRX compared to the GC-chassis WRX, the gear ratios are changed to the same specifications as the Japanese-spec WRX to improve acceleration.
Rev. D (2004)
The WRX received the same Peter Stevens-designed facelift that rest of the Imprezas received. The engine powerplant was improved to 225 PS (165 kW). Some cost reductions were made, such as downgrading the stereo.
Rev. F (2006)
2006: Europe receives WRXs with the EJ25. The power output is 230 PS (169 kW) @ 5600 rpm with 32.6 kg·m (236 ft·lbf, 320 N·m) @ 3600 rpm. The car weighs 1,405 kg (3,097 lb). The final drive ratio on this car is 4.111:1. The car also received the same facelift as the other markets.
GC chassis comparison with the GD chassis
Subaru claims that the GD chassis is 148 percent and 82 percent stiffer in torsional and beam rigidity, respectively, than the GC chassis. This stiffness is primarily due to the addition of a steel “ring” which encircles the cabin at the B-pillar. While the stiffness was increased for passenger safety, it has the added benefit of providing more stability for motorsports events.
In terms of safety, the GD chassis scored much higher than the GC chassis and earned a “Good” rating (highest mark) from the IIHS’s offset crash test. 4 stars front driver, 5 star front passenger and 4 star side safety ratings from the NHTSA. In a magazine article from the Dec. 2005 Firehouse magazine (a periodical written and made for firefighters), Ron Moore writes how it is well-known that the Impreza chassis has great protection in its B-pillars. This side structure has 8 layers of high-strength, high-tension steel including a round steel bar running through the middle. The author notes how drivers simply walk away from horrific side-impact accidents.
The GD chassis gains nearly 200 kg (441 lb) in weight over the GC chassis. Most of this weight comes in the form of chassis stiffening as the car was made to meet every country’s crash standards. The GC Imprezas were notable for being very lightweight despite having all-wheel drive. The WRX Type R STI Version VI using the GC chassis, at 1,260 kg (2,778 lb), was lighter than the competing Mazda RX-7 type RZ (1,270 kg (2,800 lb)) and Honda NSX type S Zero (1270 kg). In this fashion, the GC chassis has a better advantage.
The author of the aforementioned article also notes that the Jaws of Life need to cut the Subaru’s B-pillars at certain points in order to cut through the car frame. This information was not widespread before, so there have been many incidences where firefighters could not cut the B-pillars due to Boron being used at certain points, namely the top and bottom of B-pillars. This may become a concern if the driver or passengers need to be cut out of the vehicle quickly and the rescue technicians are unaware of this. Boron is an increasingly common addition to many modern vehicles today.
GE/GH chassis (2008–2012)
|Body style||4-door sedan
|Layout||Front-Engine All-Wheel Drive|
224 hp, 226 lb·ft (306 Nm);
265 hp, 244 lb-ft (331 Nm)
|Transmission||4-speed automatic(w/SPORTSHIFT manual mode)
|Wheelbase||103.1 in (2,619 mm)|
|Length||sedan: 180.3 in (4,580 mm)
hatchback: 173.8 in (4,415 mm)
|Width||2008–2010: 68.5 in (1,740 mm)
2011–: 70.7 in (1,796 mm)
|Height||58.1 in (1,476 mm)|
Subaru Impreza WRX STi
The Impreza WRX was redesigned for the 2008 model year and is now based on a shortened Subaru Legacy platform. The new chassis represents a departure from some Subaru traditions with full framed doors and a hatchback body style for the STI and WRX versions. Subaru made an effort to control the weight of the new chassis. Despite the increase in size, stiffness, and safety equipment, the car’s weight is similar to the previous chassis at 3,142 lb (1,425 kg) for the 5 speed manual and 3,208 lb (1,455 kg) for the 4 speed automatic.
The engine used is still the EJ255. The front suspension uses a MacPherson strut setup with steering ratio of 15:1, while the rear is a new double wishbone suspension. The US-spec WRX reverts back to a 2-piston/1-piston sliding calipers (dropping the 4-piston/2-piston fixed caliper setup), but have grown to 11.6-inch (295 mm) in the front and 11.3-inch (287 mm) in the rear, the same as the BL5-chassis US-spec Legacy 2.5i.
2008 WRX Spec
- 2.5L 4-cylinder: 224 hp (167 kW; 227 PS) @5200 rpm (400 rpm lower than previously), 226 lb·ft (306 N·m) @2800 rpm (800 rpm lower), 6500 rpm redline
- 17″ x 7″ alloy wheels with 205/50 R17 all season tires
- Vehicle Dynamics Control (VDC)
- Anti-Lock Brakes (ABS) with Electronic Brake-force Distribution (EBD) and brake assist
- Hill-Holder system on manual transmission models
- Touch-screen GPS navigation system (optional) [ Not available on Canadian Impreza/WRX models ]
- 80 watt 6-speaker audio system with single-disc CD player (standard) or 100 watt 10-speaker w/in-dash 6-disc changer including satellite radio capability (with Premium package)
- Auxiliary inputs for portable multimedia devices
- Dual-stage heated front bucket-seats (with Premium package)
- 60/40-split flat-folding rear seats
- US based 08+ wrx come with a R160 open rear diff.
- AUDM based 08+ wrx come with a R180 torsen helical LSD diff
2009 Subaru Impreza WRX
In response to criticism that the new 2008 WRX’s suspension was too soft, and needing to keep on par with rival car companies new releases, some changes were made for the 2009 model year. The EJ255 received a boost of 41 horsepower (31 kW) and 18 lb·ft (24 N·m) of torque, bringing the total output to 265 bhp (198 kW; 269 PS) and 244 lb·ft (331 N·m) of torque by swapping the previous TD04 turbo to an IHI VF52. This WRX is capable of 0–60 mph in 4.7 seconds and a standing 1/4 mile in 13.5 seconds at 102 mph (164 km/h). In addition, the 2009 model received stiffer suspension parts from the STi model, an aerodynamic package and Dunlop SP Sport 01 summer performance tires as standard equipment. Cosmetic changes included an updated mesh grill with WRX badge and darker wheels. The WRX is also only available with 5-speed manual transmission. In the USA, the 4-speed automatic is only available on a new Impreza model called the 2.5 GT, which features the same 2.5L 4-cylinder 224 hp (167 kW; 227 PS) Subaru Boxer Turbo engine as in the 2008 WRX. While in Canada, the 265 hp (198 kW) engine was an option on WRX 265 models in 2009 and the 224 hp (167 kW) is discontinued in Canada for 2010.
2011 Subaru Impreza WRX
For year model 2011, the Impreza WRX got the widebody look in both sedan and hatchback, which are the same body shells as the STI, as well as the addition of quad muffler tips with diffuser which changes the look of the rear end. The new model gains 33 pounds over the previous 2010 WRX models. The wider body gives the 2011 WRX wider track dimensions. The new exterior design is being marketed to attract younger buyers. For the US market, the WRX is offered in the Base, Premium, and Limited trim levels. As of June 14, 2011, it is reported that the 2011 model year may be the rarest ever released due to the recent disasters in Japan. Subaru dealerships are no longer taking orders for the 2011 model year.
An approximately 1.5-inch (38 mm) increase in front and rear track, firmer rear sub-frame bushings and wider 17-inch wheels and tires deliver improved grip in the 2011 WRX. The standard wheels are now 17 x 8 in (203 mm). vs. 17 x 7 in (178 mm). in the 2010 model, and tire size is now 235/45R17 vs. 225/45R17.
Subaru Impreza 2007 WRC
Subaru Rally Team revealed the new 2007 Impreza WRC Car on Friday 2 March with just seven days before the Rally of Mexico. Petter Solberg and Chris Atkinson have big hopes for the new Impreza after their not-so-impressive 2006 season in which they could not even win a single rally. As the teams left their base in England heading towards what will hopefully be a competitive weekend for rally Mexico they released details of the 2007 Impreza that will be competing for the rest of the season.
From the outside the New Impreza doesn’t look that different. Most of the work has been carried out on improving the performance and creating a car with more balanced tire wear. The team has worked with engineers and designers in Japan focusing on weight distribution, suspension and differential set ups and new dampers have been used to improve road holding.
The work on the new engine has been aimed at weight reduction. The work has included producing a new intercooler design with a turbo air inlet now going through the bonnet scoop. The FIA’s rules about aerodynamics have led to the removal of several apertures on the front and side of the bodywork which have been partially blanked off. The airflow under the bonnet now emerges through air exit holes on the side rather than in the middle of the bonnet.
The Impreza’s hydraulic control of the centre differential has been redesigned to improve its effectiveness and the exhaust has been moved to exit out of the rear bumper. The Subaru team has already started to design the ’08 car but no decisions of when it will make its debut have been decided.
Currently only the higher powered version of the WRX, the WRX STI is homologated for Group N rallying. However, the S9 and newer models of the Impreza WRC car have a GDA chassis code. This fact signifies that the Impreza WRC cars are built off the WRX chassis rather than the STi chassis.
In the PGT class the WRX has overall average performance.
2004: The WRX takes third place in PGT class.
2005: The WRX takes first place in PGT class.
2006: The WRX stands in the top 10 positions of PGT class.
The WRX is a common car found in all of the AWD classes.
2006: WRX STI 1st and 2nd place in Stock AWD (SA)
2007: WRX STI 1st and 2nd place in Stock AWD (SA), WRX 1st Prepared AWD (PA), WRX 1st Modified AWD (M4)
2009: WRX 1st in both Prepared AWD and Modified AWD.
SCCA Solo Events
2002 to 2005MY US-spec WRXs are allowed to compete in D Stock (DS), Street Touring Extreme (STX), E Street Prepared (ESP) and Street Modified (SM) classes.
2006 to 2007MY US-spec WRXs are allowed to compete in D Stock (DS), Street Touring Xtra (STX), E Street Prepared (ESP) and Street Modified (SM) classes.
2008MY US-spec WRXs are classed in D Stock (DS), Street Touring Xtra (STX), E Street Prepared (ESP) and Street Modified (SM).
2009MY and newer US-spec WRXs are classed in D Stock (DS), Street Touring Ultimate (STU), B Street Prepared (BSP, on the same line with the STi) and Street Modified (SM).
The 2002 to 2005MY WRX has been dominating the STX class. Since the inception of the Street Touring Extreme class, the WRX has taken first place as the ProSolo National Champion every year of competition (2002–2010).
2002: Tom Hoppe takes a 2002 WRX sedan to a first place DS finish at the ProSolo Finale in Topeka, Kansas.
2003: At the ProSolo Finale in Topeka, Keith Casey takes a 2002 WRX wagon to a first place finish in Street Touring Extreme (STX) class. Tom Hoppe takes a 2002 WRX sedan to second place finish in STX at the same event. At the Topeka Solo National Championship, Keith Casey drove his 2002 WRX wagon to first place finish in the supplemental STX class.
2004: At the ProSolo Finale in Topeka, the 5 top positions in STX are taken by WRXs. Josh Sortor (2002 WRX sedan), Tom Hoppe (2002 WRX Sedan) and Mike King (2005 WRX sedan) took 1st, 2nd and 3rd place respectively. At the TireRack SCCA Solo National Championships, Tom Hoppe (2002 WRX Sedan) and Mike King (2004 WRX sedan) took 1st and 3rd place respectively in STX.
2005: At the ProSolo Finale in Topeka, Josh Sortor and Mike King take 1st and 3rd place in STX. Josh Sortor also takes 1st place in TireRack Solo National Championships in STX.
2006: The top 5 positions in STX at ProSolo Finale (Topeka, KS, the first year at Heartland Park) are taken by WRXs. Billy Brooks (2003), Jeff Barco (2005) and Greg McCance (2002) took 1st, 2nd and 3rd place respectively. TireRack Solo National Championships have the top 3 positions in STX taken by Steve O’Blenes (1st), Jeff Barco (2nd) and Chris Fenter (3rd).
2007: At the SCCA TireRack Solo National Championships, 5th in STX is taken by Greg McCance (2002 WRX) and 1st in DSL by Karen Kraus (2006 WRX). Justin Rest (2006 WRX) wins the ProSolo DS Championship by winning the ProSolo Finale.
2008: At the SCCA TireRack Solo National Championships 1st in STX is taken by Greg McCance (2002 WRX), and Drew Little (2004 WRX) captures a 4th place trophy in ESP. At the ProSolo Finale, Karen Kraus (2006 WRX) finishes first in L1, which gives her the ProSolo L1 championship for the year. James Feinberg finishes second in DS at the ProSolo Finale while driving Kraus’s 2006 WRX; the finish position gives him the points to win the ProSolo DS Championship, and the SCCA rulebook reflects the car he was driving at the Finale, not the Integra Type R he ran most of the year.
2009: At the SCCA TireRack Solo National Championships, Greg McCance (2002 WRX) finishes 2nd in ESP while codriver Billy Brooks takes 3rd; Drew Little (2004 WRX) grabs the fifth place trophy. Karen Kraus (2006 WRX) wins a three car ESPL class. Mihai Surubariu (2004 WRX) wins STX at the ProSolo Finale, giving him the ProSolo STX Championship for the year.
2010: At the SCCA TireRack Solo National Championships, Greg McCance (2002 WRX) finishes 3rd and codriver Billy Brooks comes in 5th out of 27 drivers. Drew Little (2004 WRX) and Karen Kraus (2006 WRX) finish just out of the 8 trophies in 9th and 10th spots, respectively. On the ProSolo side, James Wilson (2002 WRX) takes the STX Championship with a second place finish at the Finale event, and Greg McCance wins the ESP ProSolo Championship on the strength of his win (by a scant 0.059s over Mark Madarash (Firebird) at the Finale event.
Currently only the higher powered version of the WRX, the WRX STI, is homologated for racing.
Open Track Challenge
2002: Gary Sheehan drives a 2002 WRX to win all 7 races in the Unlimited 3 (U3) class and thus win overall in U3. The car places 5th overall.
NASA U.S. Touring Car Championship
2001: Gary Sheehan debuts in a WRX to ultimately gain 2nd place.
2002: Gary Sheehan again drives the TeamSMR WRX to 2nd place.
2003: Gary Sheehan drives his WRX to 2nd place. In its final form under Gary Sheehan, the WRX is equipped with a competition swaybar kit from Hotchkis Tuning, Enkei RPF1 wheels, Cobb Tuning assembled engine, a white Delrin shift knob, C-west body kit, Cusco 35:65 torque split center differential, Kaaz front and rear LSDs, Vishnu Turboback exhaust, DMS50 coilovers, StopTech brakes and other miscellaneous upgrade parts.
2005: Brian Locke of GOTO Racing drives the WRX he purchases from Gary Sheehan to 2nd place. The WRX is refreshed and parts were changed out.
SCCA World Challenge
The WRX is classified in the Touring Car (TC) category.
2005: Irish Mike’s Racing (IMR) begins campaigning a WRX. The car manages a season high of 12th place.
2006: Irish Mike’s Racing campaigns the WRX for 2 races until it is demolished during a practice session. At this point Subaru of America pulls out its contingency funding. IMR pulls from the race due to lack of funding.
2009: Phoenix Performance will enter the first race with driver Andrew Aquilante.
SCCA Club Racing
As stated by the rule book, the 2002MY to 2004MY WRX and 2006 MY WRX TR are placed in the Touring 3 category.
The WRX was originally sold only in Japan. The same year, it was made officially available in Oceania and Europe. In 2001, North America received the first WRX as a GD-chassis for the 2002 model year.
Subaru Impreza WRX STI Specifications
The Subaru Impreza WRX STI is high performance specification model of the Subaru Impreza compact car line, manufactured by Japanese automaker Fuji Heavy Industries Subaru.
In 1988, FHI created Subaru Tecnica International (STi)as a 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 Nov. 1992 and the following year’s debut of the Group A rally car into the WRC, an ‘STi version’ was made commercially available in Jan. 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. Used STI cars usually command a higher resale value and continue to be highly sought after.
FHI 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.
First generation (1994–2000)
|Body style||2-door coupé
5-door station wagon
|Engine||2.0 L H4|
|Wheelbase||99.2 in (2,520 mm)|
Subaru Impreza WRX
The first generation STI tuned road going cars were only developed and sold in the Japanese market. Although marketed by numerical version indicators up to ‘Version VI’ in the catalogue, there were in reality more than 20 different possible types of Impreza STI cars for sale. Many of these were in different body styles and some designed as a base for motorsports use. Others, such as the 22B were special limited versions but had different specifications. Visually it is hard to tell the difference between versions or the non-STI Impreza WRX. Unlike its rival car the Mitsubishi Lancer Evolution, which sported a quite distinct exterior design difference, the Impreza WRX and WRX STi version had mainly mechanical modifications. One way to identify the version is through the VIN plate on the chassis. Sedan and Coupé STi model codes are named GC8, (USDM coupés have a separate chassis code of “GM”) and Station Wagons are named GF8, followed by a letter from A to G. A GC chassis version of the RS was released for the USDM in 2001.
One common misconception is that every Impreza between 92–01 were “GC8′s”. The code breakdown is as follows;
G – stands for Impreza,
C – sedan, and coupé for Japanese Domestic Market,
M – coupé, for US Domestic Market,
F – station wagon,
4 – stands for the 2.2 L naturally-aspirated motor
8 – stands for the 2.0 L motor (Either turbo or NA)
So really, there are many combinations. A coupé STi would be GC8, sedan GC8 also, and wagon GF8. The code for the coupé American 2.5RS’s was GM6 (6 standing for the 2.5 L N/A motor). There are also non turbo GC8′s from the Japanese Domestic Market, as with the 2L N/A HX20s, or 2L N/A AVCS SRX
To tell the difference between a JDM Sedan and Coupe chassis from the applied model code only, a sedan will have the fifth digit as a 4, representing 4-doors, and a coupé will have a 2, representing 2-doors. For example, a Version 4 STi coupé could have the code GC8E2DD, with the 2 representing 2-doors A Version 4 STi sedan could have a code of GC8E4ED
Japanese Domestic market
Version I (01/94) – GC8B
The first STi was known simply as WRX STi (there was no “version” moniker added to the name until the version II). 100 Imprezas per month were produced starting from February 1994. In March, production was stabilized to 100 STis a month. It had 250 PS (184 kW; 247 bhp) at 6500 rpm and 31.5 kgf·m (309 N·m, 228 ft·lbs) at 3500 rpm and weighed 1230 kg (2,710 lb). Before the STi, the highest trimline of the Impreza was the WRX and the WRX RA, first manufactured in November 1992. This version of the STi was the only version where the standard cars were taken at the end of the assembly line and replaced by STi parts. After this version, the standard STi was built alongside the WRX on the production lines.
The WRX STi Type RA (marketing has made usage of the RA acronym in various ways; Record Attempt is the current usage. “R = Racing, A = Group A, FIA the racing class the WRC Impreza competes in” has also been confirmed by Subaru of Japan; the correspondence can be seen on the discussion board for this article) strippo version produced 275 PS (202 kW; 271 bhp) and 32.5 kgf·m (319 N·m, 235 ft·lbs) of torque. This version of the WRX STi was a stripped out car that had no sound-deadening, radio or air-conditioning. It came sparsely equipped as it was to be sold to racing teams that would throw out the cheap parts for racing parts. This version of the WRX came with a Driver Controlled Center Differential (DCCD). This device was an electromechanical differential that could lock the differential. The DCCD would be beneficial to people who used it in various rally conditions.
Version II (09/94 – 08/96) – GC8C
The regular STi’s engine output stood at 275 PS (202 kW; 271 bhp) and 32.5 kgf·m (319 N·m, 235 ft·lbs) of torque. This was the year that STi started painting the intake manifold red. The car weighed 1,240 kg (2,734 lb) and had gold wheels like those on the World Rally Championship Impreza.
The V-limited STi edition was produced. It was a limited edition that was often used to celebrate a Manufacturer or Driver title award to Subaru’s World Rally Team. The interior is colored blue on the seat inserts and carpeting. The WRX Type RA STi received a radio and air-conditioning in the V-limited form. 1000 WRX STi Version 2 V-limited were produced. 555 (the cigarette brand that was the premier sponsor of the Subaru World Rally Team and became synonymous with the Impreza WRC livery) WRX Type RA STi Version 2 V-limited were produced.
Version III (09/96 – 08/97) – GC8D
It developed about 300PS but output was reported at the then-established gentlemen’s agreement power limit of 280 PS (210 kW; 276 hp). Torque peaked at 4000 rpm with a value of 35.0 kgf·m (343 N·m, 253 ft·lbs). In standard form, this version has a top speed of over 240 km/h. The car gained 10 more kilograms and weighed at 1,250 kg (2,756 lb). The STi shared the same face lift that the rest of the Impreza line received.
With Version III came the start of the coupé version of the WRX STi. It is called the WRX Type R STi. The coupé was chosen by Prodrive for use in the WRC because it was lighter and stiffer than the 4-door version, although it carried the same exterior dimensions. It was essentially a 2-door version of the WRX Type RA STi meaning it had DCCD, minimal sound insulation, close-gear ratios and hardened gearbox. This car also has a water-spray nozzle to dampen the top of the intercooler. The water will then evaporate, taking heat away from the intercooler and cooling the intake charge. This car was produced on an order-only basis.
Also, there was a WRX STI type RA (4-door) available in Version III. These have the same motor, gearbox and R180 diff as the Version III WRX STI Type R, including DCCD, aluminium bonnet and front guards, no sound deadening and thinner glass. The ECU is also an exclusive tune. The Type R tends to be a bit stiffer and weighs 1,190 kg (2,600 lb). The DCCD has been known to bite new drivers in the wet. The RA gets a roof vent instead of map lights, and wind up windows, although electrics are an option from factory.
Also available was a WRX Type R V-limited, in version III. It has a WRX motor with no forged internals like the STI, and it misses out on the 4 pot front brakes as they are to be installed by rally teams. It has a roof vent and is lightweight, making a good base for a rally car.
Version III STI runs a VF23 IHI ball bearing turbocharger while the JDM non-STI gets a VF22.
Version IV (09/97 – 08/98) – GC8E
Power remained at 280 PS but torque was raised from 253 lbs./ft of torque to 260. Forged pistons were also added.
The interior and the cockpit were changed into a newer design along with the new “White color” gauges. (white faced)
Version V (09/98-08/99) – GC8F
The power stayed the same as the previous version 280 PS . The engine layout and design was made cleaner and was dubbed as the Boxer Phase 2 engine. The facelift the rest of the Impreza line had was also applied to the STi. The WRX STi weighed 1,270 kg (2,800 lb). There were 1000 WRX Type RA STi Version 5 Limited cars and the WRX Type R STi Version 5 Limited cars had a 4 month waiting period for each order. The interior was also changed slightly from the Version 4 including seats and steering.This model was also produced as a 555 limited edition.
Version VI (09/99-08/00) – GC8G
Most of the changes were cosmetic. The wing was sculpted to be more aggressive. VF28 spec turbo with max boost at 1.2 BAR and produced 224 kW (305 PS) and 388 Nm There were 2000 WRX STi Version 6 Limited, 500 WRX STI Type R coupe Version 6 Limited and 2000 WRX STi RA Version 6 Limited cars produced. Also 500 WRX STi Version 6 Limited Hatchback models.
Japanese special variants
22B STi (03/98 – 08/98)
In 1998, Subaru of Japan produced a widebody, 2-door, Impreza called the 22B STi. The 22B was used to commemorate both Subaru’s 40th anniversary as well as the 3rd consecutive manufacturer’s title for Subaru in the FIA World Rally Championship. On the release of the sales, all 400 Japanese units sold out from 30 minutes to 48 hours, depending on the report. The cars had the starting VIN code of GC8E2SD. Another 24 were produced for export markets – see the 16 22B Type UK below, along with another 5 for Australia, and 3 prototypes.
The 22B had the EJ22 engine as opposed to the regular EJ20 engine. (Note internal Subaru material states the block comes from a V3 EJ20G, not the EJ22G as most think. Also the intake manifold and heads were from the V4 EJ20K) This means the displacement was increased from 1994 cc to 2212 cc. The block is a closed-deck design. The heads (valves, valvetrain and such) were lifted from the STi Version 4 engine. It produce 280 PS (210 kW; 280 hp) at 6000 rpm and 363 N·m (267 ft·lbf, 37.0 kgf·m) of torque at a lower engine speed of 3200 rpm. The redline is 8000 rpm. The compression is an 8.0:1. The turbocharger is an IHI RHF 5HB (the internal company usage code is VF23, although a number of the cars received the larger VF22).
In performance terms, the donor STi Version 4 is capable of a 12.8 second quarter mile. The 22B, which carries an additional 20 N M of torque, has been timed at 12.5 seconds, however AWD cars can be difficult to launch, due to potentially bogging down if engine speed is too low, or the clutch is not correctly taken up.
This car was given a unique color of blue and had fender flared widebody taken from the Peter Stevens designed WRC car, thus widening the width by 80 mm (3.15 inches) for a total of 1,770 mm (69.7). During assembly, a WRX Type R chassis was taken off the line. The fenders were replaced with the 22B STi fenders. The car’s curb weight is 1,270 kg (2,800 lb). The suspension is provided by Bilstein. The brakes were Brembo manufactured standard 4-piston/2-piston brakes. However, the color is red and the Subaru name cast on the brake calipers and painted white. The wheels were increased in size from the standard WRX Type R STi from 16×7″ to 17×8.5″ BBS Elektra wheels. The car is shod with 235/40 ZR17 Pirelli P Zeros. The clutch was upgraded to a sintered twin clutch with a ceramic disk. The transmission ratios are the same as the standard WRX Type R, but the gears were shot-peened for added reliability. The car has a unique hood, front and rear fenders, a WRC-inspired front bumper and a unique adjustable rear wing.
The origin of the name 22B has often been debated. Many assume 22 referred to the 2.2 liter displacement and the B was for the Bilstein suspension. This would correlate with the idea that Subaru sells a Legacy Spec B, where the B represents the Bilstein suspension. Others believe that 22B was meant to represent the much recognized 555 decal (555 is a tobacco company that was a major sponsor for Subaru in the WRC) on the WRC car as 22B is a hexadecimal representation of the decimal number, 555.
The 22B STi that is supposed to be #13 was never given the plaque. Subaru of America imported #13 to be used as a press car. Three prototype 22B STis were given the #000 plaque, 2 went to the World Rally car drivers for Subaru at the time Colin McRae and Nicky Grist, with the third being used by Subaru Japan as their press car. It was widely rumored David Lapworth of Prodrive owned the third #000 car, however he actually owned #400.
S201 STi (2000)
Subaru Tecnica International started the S-series of special Imprezas. This series is a limited production series that sports an engine output of greater than 280 PS (210 kW; 280 hp) [had 224 kW (305 PS)] (special variant cars were excluded from the gentlemen’s agreement). The car was decked with nearly every single part from the STi catalogue.
The S201 was a 4-door STi that sported the only body-kitted S-series WRX STi. It had a tri-planar wing and a massive front airsplitter. The entire suspension was composed of STi parts.
There were 300 S201s produced, they used a VF28 spec turbo, with max boost at 1.2 BAR and produced 224 kW (305 PS) and 353 Nm, weighing in at 1270 kg these are a highly desirable variant.
United Kingdom special variants
22B Type UK (1998)
16 of the ‘export’ 22Bs (see above) were modified by Prodrive, with longer gear ratios, UK specification lights and an official 3 year warranty. Because 50 22Bs had already been imported privately into the UK, Subaru UK had to wait until 1999 to register the 22B Type UKs under the VCA’sSingle Vehicle Approval scheme. The price was £39,950, approximately the same price that grey import 22Bs were being sold for.
To counter the grey imports of high-performance Japanese variants, Subaru UK commissioned Prodrive to produce an ‘official’ limited edition of 1,000 two-door cars in Sonic Blue. The chassis was a 2-door coupé. They were taken from the STI Type R lines and used for the P1. The car was the only coupé version of the WRX STI GC chassis to receive ABS. In order to allow for ABS, the DCCD was dropped. Engine output was boosted to 276 bhp (206 kW; 280 PS), and the suspension optimised for British roads. Options were available from Subaru consisting of 4 piston front brake calipers, electric Recaro seats, 18″ OZ alloys and a P1(Prodrive) stamped backbox. The P1, or Prodrive One, is echoed in the name of the Prodrive P2 concept car. coupé л
Second generation (2000– 2008)
|Body style||4-door sedan
4-door station wagon
|Wheelbase||2004–05: 100.0 in (2,540 mm)
2006–08: 99.4 in (2,525 mm)
|Length||2004–05: 173.8 in (4,415 mm)
2006–08: 175.8 in (4,465 mm)
|Width||68.5 in (1,740 mm)|
|Height||56.3 in (1,430 mm)|
|Curb weight||3,296 lb (1,495 kg)|
Subaru Impreza WRX
In 2000, the Impreza line received a complete update. The chassis was stiffened so that it had 120% torsional stiffness increase. The WRX STi gained 17″ x 7.5″ alloy wheels over the previous 16″ x 7″ wheels. The 5 speed manual transmission (reputed to be one of the car’s weakpoints) was changed to an STi engineered 6 speed manual transmission. The engine was retained from the Version 6 STi and still retains the semi-closed deck block and is still labeled as the EJ207, however the engines did gain Variable Valve Timing (AVCS) further improving their low end torque production. The interior was updated with a STi logo on the gauge. The STi’s tachometer also has a red shift light. The STi’s and optioned Type RA STi have received Brembo 4 piston front and 2 piston rear brakes while the bare-bones Type RA STi still carried the Subaru 4 piston front and 2 piston rear brakes. Externally, the STis had larger hood scoops and hadfoglight covers with STi embossed on them. The DCCD was updated so it can work with anti-lock brakes. During braking, when the ABS is on, the DCCD will set itself to open-mode (no locking).
The version nomenclature was dropped from the name. Japanese and other auto-enthusiasts often refer to the chassis as GDB/GDF (the STi has a ‘B’ or ‘F’(for USDM models) whereas the regular WRX had an ‘A’). The fourth character of the VIN gives the revision (A to F where G is the 2007 version).
For quick and easy reference to the different exteriors, Subaru Impreza owners use nicknames based on the headlights. Often relating to a creature that has similar looking eyes: 2001–2003 are ‘bug eyes’ / 2004–2005 are ‘peanut eye’, or ‘blob eyes’/ 2006–2007 are ‘hawk eyes’.
Rev. A (2000)
In 2000, the WRX STi received the aforementioned updates. The WRX Type RA STi was produced. The STi wagon was still produced but its engine only produced 275 PS (202 kW; 271 bhp) . The STi foglight covers had white STi lettering on them.
The WRX Type RA STi was used for the Group N homologation.
Rev. B (2002)
Along with the rest of the Impreza line, the grille and body of the WRX STi was minorly updated by Peter Stevens to give it a more angular look when seen from the side. The foglight covers had pink STi lettering. Not much else besides minor suspension improvements and a small increase in torque output was done.
The WRX Type RA STi was dropped for a new WRX STi Spec C. This model was much lighter than the WRX Type RA as it received lighter glass and body panels. The Spec C’s handling was much improved due to an increase in caster(from 3.5 degrees to 5 degrees). This was achieved not by changing the suspension mounting point, but by lengthening the wheelbase (15 mm). This was done by including different control arms. This increased caster significantly helped the turn-in capabilities of the car. The Spec C also has a steering rack ratio of 13:1. The transmission is supplied with its own oil cooler.
The WRX STi wagon had ceased to be produced.
Rev. C (2003)
Little change from Rev. B.
The WRX STi was used for Group N homologation.
Rev. D (2004)
The WRX STi received the same Peter Stevens-designed facelift that rest of the Imprezas received. The WRX STi is now capable of being ordered with DCCD.
The WRX STi Spec C Type RA was released. It sported a carbon-fiber wing and a carbon fiber lip. It also had a new set of BBS wheels as well as a newly tuned engine.
The WRX STi V-Limited was released. It sports 4-way dampers tuned by Subaru World Rally Team’s Group N driver Toshi Arai.
The WRX STi was used for Group N homologation.
Rev. E (2004)
This was the first Impreza STi model to be offered in the United States. Subaru unveiled this model in the Detroit International Auto Show, only 1 month after Mitsubishi announced the arrival of the 271 horsepower Lancer Evolution 8, which out-performed the 2.0L WRX.
The 2004 WRX STi is considered to be the lightest (3263 lbs, official brochure and tested by Car & Driver Magazine) and rawest among 2004–2009 models. The car was sold in the US without a radio or floormats. The car was rated at 300 bhp and 300 lbs-ft torque, although many feel it was under-rated on purpose. What made the car so special to most is the level of performance offered for a mid 30 thousand dollars car, that still has a back seat and a big trunk.
Since its launch, many upgrades became available to increase power, handling and braking capabilities.
Some weak links were discovered in most 2004–2007 models since the 2004 debut. The oil pickup line inside the oil pan was shown to develop a crack leading to oil starvation and engine damage due to the lack of lubrication when the part fails. Several aftermarket vendors have addressed this issue by re-designing factory oil pickup units with more substantial welds and materials.
Rev. F (2005)
The WRX STi receives the same increase in wheelbase as the Spec C. All STis received additional rear arch flaring in order to allow an increase in wheel size. The wheel size changed from 17″ x 7.5″ to 17″ x 8″. In accordance with the increased wheel width, steering lock-to-lock turns have been reduced. Wheel hub strength was improved. The P.C.D. was changed from 5 x 100 mm to 5 x 114.3 mm. The interior was vastly improved as well. A whole new center console now brings out a very high grade interior feel.
The WRX STI continues on relatively the same. The Impreza line’s looks have been updated.
The WRX STI Spec C’s receives the Arai tuned dampers and a 21 mm (0.8 in) swaybar. The rear suspension is changed from rubber bushings to pillowball bushings. The strut tower was further stiffened for improved handling and stability. The strut towers were reinforced for better handling and better ride characteristics. The engine mounts were changed from metal to liquid-filled plastic mounts to reduce vibrations into the car’s cabin. Some 2006 owners have had issues with these plastic engine mounts. The manufacturer will replace them, under warranty if broken, with the 2005 rubber mounts.
The DCCD is updated with the use of a torque-sensing mechanism inside the DCCD. The torque split is changed to 41/59.
The WRX STI Spec C was used for Group N homologation.
The WRX STI Spec C Type RA was released in November 2005, with 350 units produced. The Type RA added the following to the Spec C model from the STI parts catalogue: 4-way STI adjustable inverted struts, STI Japan-spec pink springs, STI rear lateral links, STI rear trailing links, STI 21 mm (0.8 in) rear sway bar, STI rear pillowball suspension, STI 110 mm (4.3 in) opening rear axleback exhaust, STI 17″ x 8″ Enkei-made wheels and STI V-lip front spoiler.
Rev. G (2007)
The WRX STI and STI Spec C is mechanically similar to the previous revision.
Changes include a different turbocharger VF43 equipped with a slightly larger wastegate port to prevent boost creep (VF43, as opposed to VF39 in the older version) and revised gearing on the 6 speed manual transmission. They also use top feed injectors instead of side feed injectors like the previous STi models(04-06USDM). This means the intake manifold is a bit different as well as the TVG (Tumble Valve Generators) used for emissions on cold start-ups.
Japanese special variants
This car was an S-series Impreza based on the Spec C. All of the suspension and powertrain parts included STi parts from the STi part catalogue. The interior included special edition yellow seats with red STi logo stitching. A smaller, lightweight AC compressor was fitted to save weight. The brake rotors were gas slotted. The wheels were STi labeled Rays Volk alloys.
This limited edition Subaru was an S-series Impreza based on the WRX STi. Again it is basically a car with all the STi parts available. It was sold with custom made 18-inch (460 mm) BBS alloys with Pirellis.
The new S204 was released at the end of 2005. It is based on the WRX STi and similar to the S203. It does away with the roof spoiler and has a different grille from the rest of the Impreza line. The S204 has a two-litre (EJ20) H4 engine capable of developing 324 PS (239 kW; 320 bhp) and a six-speed manual gearbox. When cruising the S204 achieves 100 km/h (62 mph) at 3000 rpm in top gear and can reach 220 km/h (137 mph) at approximatively 6600 rpm.
Suspension can be described as ‘stiff’ with torsional rigidity enhanced by the inclusion of laterally mounted items described as “performance dampers” bearing both the STi logo and Yamaha. As a result cornering can be described as excellent. The addition of a carbon fibre front-lip spoiler and a rear diffuser on an already low suspension setup plus the use of low-profile Pirelli P Zero (Corsa) tyres implies the S204 is intended mostly for sealed road use.
Recaro has used carbon-fibre extensively in the manufacture of the driver and front passenger seats available in the S204. The high side bolsters provide significant support to the driver during maneuvers that induce lateral forces and are considered to be an integral feature to the cornering performance of this vehicle. The seats are rigid in design and have relatively little cushioning compared to other Impreza Models.
Advertising material produced by Subaru for the S204 indicate that a limited run of 600 S204′s were made. Individually numbered badges for each car are located within the engine bay and repeated as a small plaque situated at the base of the gear lever. However, five (5) WRX STI S204 were made available to Subaru enthusiasts in New Zealand . Unlike other S204s sent to other nations (for example 30 units for Singapore) these five cars do not display either the in-cabin or in-engine bay badging that uniquely identifies each of the reported 600 vehicles manufactured. The lack of individual badging for these five cars brings into question the real number of S204s manufactured.
WRX STI Spec C Type RA-R
At the end of October, 300 2007MY WRX STI Spec C Type RA-Rs were open for ordering. These cars are based on the WRX STI Spec C. The wheels are changed for 18-inch (460 mm), STI-branded, Enkei-made, white wheels. The engine has been blueprinted and balanced. It produces 320 PS (235 kW; 316 hp) of power. The suspension is built with the latest STI parts from the STI catalogue. The front brakes are 6-piston brembo brakes. The turbo charger is based on the larger S203/S204 twinscroll unit. The brakes are made so that they change from silver to gold when heated from usage. The rotors are slotted. The 2nd R in “RA-R” is stated by an STI engineer to mean “Radical”.February 2007 Edition Best Motoring Interview of STI engineer at 7:00 [Video no longer available]
WRX STI A-Line
This WRX STI A-Line is mechanically the same as the Japan-spec STI. The exterior has been toned down with the removal of large rear spoiler, black Brembo brakes, titanium colored Enkei wheels, a black STI front lip and leather seats in order to target the more mature market.
Asia, Oceania and European specifications
In 2000, most of Asia, Oceania and Europe received the new STi. The engine was detuned to meet emission standards. Engine output was variously rated from 265 PS (195 kW; 261 hp) to 280 PS (210 kW; 280 hp) depending on market.
2005 STis received the long awaited DCCD control available in other markets, as well as a slight wheelbase increase to match the Japanese-spec WRX STi Spec-C and has 280 PS (210 kW; 280 hp).
In 2006, the model was facelifted like all STIs and the engine was changed to the EJ257 producing 280 PS (210 kW; 280 hp).
United Kingdom special variants
A limited edition of 1000 Japanese MY04 WRX STI’s with DCCD were exported to celebrate victory in the 2003 WRC drivers’ championship. 500 were sold in Europe, Australia and South Africa as the Petter Solberg edition; the other 500 were further modified by Prodrive and sold in the UK as the WR1. They had 320 bhp (239 kW) and 309.8 ft·lbf (420.0 N·m), an incredible 0–60 mph time of only 4.25 seconds and a top speed of 155 mph (249 km/h) (electronically limited). They were equipped with Prodrive WRX STI springs, Pirelli PZero Nero tires, mesh grilles, special Ice Blue metallic paint and Prodrive PFF7 Pewter wheels. The new ECU and exhaust were not EU-homologated, so they were fitted after registering the car. The retail price was £29,995.
Spec D (2006)
A ‘discreet’ version of the STI was made for a more conservative market. It is similar to the Japanese-spec A-Line except it had a regular WRX spoiler on the boot, silver wheels (not Gold) and no rear roof vane. As standard it has projector-style fog lights, Smartnav with touch screen operation, Vehicle Tracker,and safe speed system. A 200W Pioneer DEH-P70BT head unit, iPod adapter and Bluetooth phone connection were also included. The interior featured standard leather trim on the seats and doors, Auto climate control and extra sound insulation. It was limited to a run of 300 cars in only Crystal Grey Metallic so therefore is even rarer than the RB320. Power on this model is rated at 276 bhp (206 kW). It has a 0–60 time of 5 seconds and a top speed of 155 mph (electronically limited). New retail price was £28,450.
Echoing the RB5 a limited edition of 320 2007MY cars in Obsidian Black Pearl were released “in memory of Richard Burns”, the 2001 WRC World Champion who died in 2005 due to a brain tumor. The car produces 320 PS (235 kW; 316 hp) of horsepower and 450 N·m (332 lb·ft) of torque due to tuning by Prodrive. The suspension has been upgraded with Eibach springs, an Eibach rear stabilizer bar and Bilstein struts. It rides on 18″ anthracite alloys. A £1500 option on the car was to have the interior changed to a black leather/alcantara with RB320 stitching on the seat and a new gear (shift) knob. The car has special silver mesh grilles. New retail price was £29,995.
United Kingdom unofficial variants
Litchfield Type 25 (2004)
Litchfield Imports initially imported Japanese specification Subarus, including the Spec C, into the UK. The motivation for them to create a new version of the Impreza came when Subaru removed creature comforts like air conditioning and electric windows from the Spec C at the end of 2003. Iain Litchfield wanted to continue to offer an ‘everyday’ Impreza as fast as the Spec C. Litchfield saw the potential of the newly released USDM EJ257 and imported it, and Iain Litchfield modified car, tuning it to produce 350 bhp (261 kW). The engines were installed into a Japanese specification STI and upgraded the suspension with rebound adjustable AST Sportline I coilovers, Whiteline anti-roll (stabiliser) bars and an anti-lift kit, with custom geometry settings. The May 2004 edition of EVO magazine. called it the ‘Best Impreza Ever’ when tested against the WR1, Spec C and P1.
Litchfield Type 25 (2007)
The new Type 25, like the previous Type-25, used a modified EJ257 block but it was built by Cosworth. They used Cosworth’s own forged pistons and connecting rods balanced to within 0.5 grams. A modified STI crankshaft and STI engine casing were used and the ‘short’ engine was assembled by hand. This ‘short’ engine was sent to Litchfield to be finished . Cosworth honed, big-valve, ported cylinder heads and cams were used and the engine was installed into a 2007 Japanese specification Spec C. The engine produces over 395 bhp (295 kW) and 420 lb·ft (569 N·m), for a power/weight ratio 1 hp higher than a Porsche 997 Turbo.It costs $10,000 more than the normal 2006 Subaru Impreza WRX STI.
Rev. D (2004)
In 2004, Subaru of America announced it would sell the WRX STi. Subaru Tecnica International’s president said in an interview with Road & Track magazine that he wished to beat the Mitsubishi Lancer Evolution in the US. Thus, each iteration of the US-spec WRX STi is essentially the same as the respective J-spec STi Spec C. All part numbers matched up, including the part-numbers for the glass windows and dampers. However, instead of the EJ207, the USA receives the first EJ257, a 2.5 liter version of the EJ207. Unlike the EJ207, it features hypereutectic castpistons as opposed to the forged pistons in the EJ207. The steering rack is the standard STi’s 15.2:1 instead of the Spec C’s 13:1
Rev. E (2005)
As with the Japanese-spec C models, US-spec STis received additional rear fender flaring in order to allow an increase in wheel size. The wheel size went from 17″ x 7.5″ to 17″ x 8″. In accordance with the increased wheel width, steering lock-to-lock turns have been reduced. Wheel hub strength was improved. The P.C.D. was changed from 5 x 100 to 5 x 114.3. The Suretrac front LSD in the 04 model was replaced with a helical unit, the rear differential remains the same clutch type unit. Torque split is set at 35/65. In the interior, the Stereo became standard. The badging has been revised and different look was given to the steering wheel, shift knob, HVAC controls, and center console.
Rev. F (2006)
The US-spec STIs receive the same facelift as the Japanese-spec STIs. Mechanically speaking, the DCCD (Driver Controlled Center Differential) and the engine mounts have been changed. Like the Japanese-spec STIs engine mounts were changed from metal to liquid-filled plastic mounts to reduce vibrations into the car’s cabin. On the largest Impreza forum, North American Subaru Impreza Owners Club (NASIOC), 2006 owners have had issues with these plastic engine mounts. The manufacturer will replace them, under warranty, if broken, with the 2005 rubber and metal mounts. Later 2006 vehicles were equipped from the factory with 2005 mounts. The center differential is updated with the addition of a mechanical limited slip mechanism to supplement the electromagnetic DCCD. The torque split is changed to 41/59. The oil pump within the transmission was also deleted. The 2006 STI weighs approximately 3,350 lb (1,520 kg).
Rev. G (2007)
The ECU was completely re-engineered in order to meet US LEV2 emissions requirements, which has caused throttle and timing issues. A secondary air pump was also added to help meet LEV2. Top Feed injectors replaced the Side Feed from the previous models.
The WRX STI Limited was introduced with fog lights, leather interior, lip trunk spoiler, and optional moonroof. It is similar to the Japan-spec WRX STI A-line, except the mechanicals of the car are based on the 2007MY US-spec WRX STI.
GC chassis comparison to the GD chassis
Subaru claims that the GD chassis is 10 percent and 82 percent stiffer in torsional and beam rigidity, respectively, than the GC chassis. Due to the increase in stiffness, the car has much better stability in corners and is easier to control at the limit.
In terms of safety, the GD chassis scored much higher than the GC chassis and earned a “Good” rating (highest mark) from the IIHS’s offset crash test. 4 stars front driver, 5 star front passenger and 4 star side safety ratings from the NHTSA. In a magazine article from the December 2005 Firehouse magazine (a periodical written by and made for firefighters), Ron Moore writes how it is well-known that the Impreza chassis has great protection in its B-pillars. This side structure has 8 layers of high-strength, high-tension steel including a round steel bar running through the middle. The author notes how drivers simply walk away from horrific side-impact accident.
One of the biggest complaints with the GD chassis is that it gains nearly 200 kg (441 lb) in weight over the GC chassis. Much of this weight came in the form of chassis stiffening as the car was made to meet every country’s crash standards. The weight also hampers the cars maneuverability, transitions and turn-in capabilities. The GC Imprezas were notable for being very lightweight despite having AWD, the WRX Type STi Version VI, at 1,260 kg (2,778 lb), was lighter than the contemporary Mazda RX-7 type RZ (1270 kg) and Honda NSX type S Zero(1270 kg). In this fashion, the GC chassis has a better advantage. However it still remains at a slighter weight by shaving 200 pounds off of its biggest competitor, the Mitsubishi Lancer Evolution.
The author mentioned above also notes that the Jaws of Life need to cut the Subaru’s B-pillars at certain points in order to cut through the car frame.
Third generation (2008–2012)
|Body style||5-door hatchback
|Engine||2.0L 304 hp (227 kW) H4
2.5L 305 hp (227 kW) H4
5-speed automatic (w/SPORTSHIFT manual mode) (Japan, Hong Kong, Singapore, Indonesia, and Australia only)
|Wheelbase||103.3 in (2,624 mm)|
|Length||173.8 in (4,415 mm)
Sedan: 180.3 in (4,580 mm)
|Width||70.7 in (1,796 mm)|
|Height||2009–2010: 58.1 in (1,476 mm)
2011–: 57.9 in (1,471 mm)
|Curb weight||3,373 lb (1,530 kg)|
Subaru Impreza WRX
The 2008 STI has received a higher degree of parts to differentiate it from its Impreza WRX brethren. Unlike the Impreza WRX, the STI uses aluminum suspension components, and has different fenders that are 2.2 in (56 mm) wider. It adopted “Subaru Intelligent Chassis Design” and “Dynamic Chassis Control Concept”. The turbo forces air through a larger top-mount-intercooler which has lost the red “STI” that was on previous generations. It is the first generation of this model with an automatic transmission which is able to import to outside Japan.
Like other 2008 Impreza models, the 2008 STI benefits from a lower polar moment of inertia due to smaller overhangs, and also features a double wishbone rear suspension. The car also borrows new intake and exhaust components from the Legacy GT platform.
The latest Impreza WRX STI features Multi-mode Vehicle Dynamics Control (VDC) with “Normal”, “Traction”, and “Off” modes, Subaru Intelligent-Drive (SI-Drive) with 3 modes: Intelligent, Sport, and Sport Sharp (S#), and Multi-mode Driver’s Controlled Centre Differential (DCCD). The DCCD enables driver to select the manual or auto: “auto”, “auto+”, and “auto-” mode in order to distribute the torque based on driving preference or conditions.
The JDM version has a 2.0L 308 PS (227 kW; 304 bhp) EJ207 engine with a Twin scroll turbocharger, while other versions of the car have a 2.5L 300 PS (221 kW; 296 bhp) EJ257 engine with a single-scroll VF48 turbocharger.
At the New York Auto Show, a Subaru spokesman confirmed that the Impreza WRC will be based on the hatch platform, due to its lower polar moment of inertia.
The latest US model of the STI has 305 bhp (227 kW; 309 PS) and 290 ft·lbf (390 N·m). of torque and range in price from $35,640 to $39,440, depending on the options included. The 2008 Impreza STI has the model code GR, reflecting the different “wide body” 5-door Hatchback compared to the GH standard body 5-door Hatchback used for the 2008 Impreza WRX and non-turbo models. The new “wide body 5-door” chassis is 70.7 in (1,796 mm) wide compared to 68.5 in (1,740 mm) for the regular WRX 5-door chassis. Curb weight varies from 1,505 kg (3,318 lb) to 1,540 kg (3,395 lb) depending on the options.
In 2008, a Subaru WRX STI spec C was in the works for production. It had been spotted lapping the Nurburgring. It is expected to shed 70 kg (154 lb) in weight, have minor engine tweaks, have an updated aero kit, and bigger brakes.
A possible precursor to the WRX STI spec C had surfaced at the MotorSport Japan 2008 auto show, named the Subaru Takumi concept. The only visual cues to differentiate this car from the regular STI are a blacked-out rear spoiler, front lip spoiler, and 12-spoke wheels that are strikingly similar to the ones featured on the spec C test mule spotted around the Nurburgring. The upgraded parts included on the car are drivetrain and suspension modifications. There is no word on performance figures or power output. It was later confirmed by Autoblog that the Takumi concept was in fact just an unveiling of the 20th Anniversary Edition WRX STI and not the spec C. All 300 examples will be exclusive to the Japanese market.
Subaru launched the Impreza WRX STI A-Line with a five speed semi-automatic gearbox on February 24, 2009. Available initially only in Japan and Singapore, the A-Line features include “Downshifting Blipping Control” and steering wheel-mounted paddles. The engine and transmission in the A-Line are very similar to 2007–2009 Legacy 2.5 GT models. However, the A-line has less torque (35.7kgfm) and slower acceleration (0 to 100 km/h takes 6.1 seconds) compared to the manual STI version, although lighter (1,490 kg vs 1,505 kg). The A-Line is also offered in Hong Kong, and later in Indonesia with debut at the 2010 Indonesia International Motor Show in July 2010, and will be exported to Australia in 2011.
Finally, on July 23, 2009, the Subaru Impreza WRX STI spec C was released in Japan. The 900 units limited edition WRX STI spec C has engine, suspension, and body parts improvement over the regular model. The ball bearing on the turbine axle had been modified to reduce friction, the ECU had been retuned for better response, and an intercooler water spray was fitted to prevent rise in the air temperature. The cross member, suspension and power steering were also improved for better handling and body rigidity. Aluminium hood, laminar window glasses, and lighter battery helped to reduce weight.
Subaru (UK) Limited introduced two new WRX STI models at the British Auto Show that have specific tuning by Prodrive. The first is WRX STI 330S, intended to compete with the UK-spec Lancer Evolution X FQ-330. It produces 330 PS (243 kW; 325 bhp) and has a 0–60 mph time of 4.4 seconds. The last of the two would be the WRX STI 380S. It could make it into production within 6 months, pending positive consumer reception. It sports new wheels and an upgraded body kit. It is expected to produce 380 PS (279 kW; 375 bhp). Currently, there are no other specs for the car. Subaru announced, on September 10, 2008, that the 380S variation will not be produced, due to homologation and specification difficulties. The regular model is called WRX STI Type UK.
For 2010 model year, Subaru of America introduced the Impreza WRX STI Special Edition. Similar to JDM WRX STI Spec C, this model came with stiffer suspension and thicker stabilizer bar for better handling. It also has 7 twin-spokes dark gray 18 inch alloy wheels. Inside, the limited-run Special Edition STI got manual air conditioner and 4-speaker stereo instead of automatic climate control and 10-speaker premium audio on the regular WRX STI.
Cosworth Impreza STI CS400
Available for the UK market only, the Cosworth Impreza STI CS400 was announced in late May 2010. Only 75 units built, the STI CS400 is powered by a 400 PS (294 kW; 395 hp) 2.5 liter turbocharged engine which has Cosworth engineered forged connecting rods, racing pistons, heavy duty cylinder head studs, multi-layered head gasket, and high pressure oil pump. The ECU had been remapped, and the new compressor design and wastegate actuator had been applied to the turbo. The exhaust system features larger capacity tubular manifold and bigger diameter downpipes. Clutch was also upgraded.
The Cosworth Impreza STI CS400 can be distinguished from the regular STI from its upper mesh grille with piano black finish on the top frame, modified front bumper with “Cosworth” emblem on the lower mesh grille, and lip spoiler, 18 inch Pro-Race alloy wheels in Antrachite Gray, and trunk waist spoiler.
To match its performance, the CS400 comes with Bilstein struts and Eibach springs for better quality ride, and better handling with less pitch and roll during cornering. Braking was updated by AP Racing’s larger diameter ventilated front brakes with six-pot calipers.
Inside, the CS400 has Recaro leather seats with “Cosworth” label, piano black center console panel, and “Cosworth”-badged floor mats.
Australia also received the 2011 model year WRX STI as 4 door Sedan and 5 door Hatch in the regular STI and luxury STI spec.R with manual and automatic transmissions offered. Electric sunroof, Leather seats, Navigation system, and BBS wheels are standard on the STI spec.R, while Recaro seats are optional.
|Japanese version||Export version||A-Line (JDM)|
|Turbo||twin-scroll turbo||single-scroll turbo||single-scroll turbo|
|Displacement||1994 cc||2457 cc||2457 cc|
|Power||308 PS (227 kW; 304 hp)||300 PS (220 kW; 300 hp)||300 PS (220 kW; 300 hp)|
|Torque||43.0 kg·m (422 N·m; 311 lb·ft)||41.5 kg·m (407 N·m; 300 lb·ft)||35.7 kg·m (350 N·m; 258 lb·ft)|
The STi serves as the basis from which Group N ”production” rally cars are constructed. Group N5-classed (marketed by FIA as Production Car World Rally Championship or PWRC) cars are the major support category for the World Rally Championship and are the premier category in many national rally championships. For two years (2004 and 2005), the WRX STi has taken the top 3 podiums in Group N. This new effort can be attributed to STi’s increased support in Group N motorsports..
In 1995, 1996 and 1997 World Rally Championships, the Subaru World Rally Team, in conjunction with Prodrive won the WRC manufacturer’s title with the World Rally Impreza. The STi’s bare chassis is used by Prodrive as the basis of the World Rally Impreza. This WRC class is currently labeled by FIA as Group A8. Colin McRae in 1995, Richard Burns in 2001, and Petter Solberg in 2003 all won the WRC driver’s title with the World Rally Impreza.
The STI has been a prominent contender in Rally America events since the series began in 2005. The STI has won every championship except for one (2010 L’Estange/Mitsubishi Lancer Evolution X). Recently, Subaru factory driver Dave Higgins drove a 2011-spec STI to a series victory.
An STi Spec C won 1st place in the All Japan gymkhana championships of 2004. Chris Torres was the driver. Sheridan and RJ were involved in a collision around turn 453
In 2005, a 2004 STi took first place in the STU class of the Tire Rack SCCA Solo Nationals. The next year at the Tire Rack SCCA ProSolo in Topeka, Kansas, STis took first place in the AS and STU classes; an STi took first place in the STU class at the Tire Rack SCCA Solo Nationals that same year.
In 2005, Chris Deable took a STI-supported WRX STI to 2nd place in the A6 class and 14th overall in the 24-hour Nürburgring race. The car was set up to have around −5 degrees of camber at the front wheels. The wheels are Enkei pieces. The car also uses the roof vane seen on the 2006MY WRX STI. The car used Tein SRC coilovers. The car was driven by Kazuo Shimizu (Super Taikyu driver and winner), Toshihiro Yoshida (Super Taikyu driver and winner), Stéphane Sarrazin (2005 Subaru World Rally Team driver) and Kumi Sato.
In 2006, Deeble-Bellchambers Racing UK campaigned a Subaru factory supported WRX STI Spec C in the 24 Hour Nürburgring’s SP 6 class. It had Motec Engine Management, 3-way adjustable AST coilovers, aftermarket Brembo brakes, an aftermarket turbocharger unit, STI Group N parts, aero pieces and many other modifications, pushing 400 hp (300 kW). To combat understeer, it ran without a front swaybar. It qualified 37th out of 225 competitors for the starting position. The Autosportif Racing UK/Subaru WRX STI Spec C managed to end with a position of 115 out of the 225, suffering 2 turbocharger unit failures during the course of the race. The car was driven by Alan van de Merwe (the 2003 British F3 champion), Briton Phil Bennett (driven in the BTCC, Le Mans and Nürburgring), Jonathan Price (6-time Nürburg 24 Hours competitor) and Chris Atkinson (2006, 2007 Subaru World Rally Team driver).
In 2011, the Subaru Road Racing Team will be campaigning a 2011 Subaru Impreza WRX STI sedan in the Grand Sport (GS) class of the Grand-Am Continental Tire Sports Car Challenge series.
In 2005 and 2006, Icy Racing’s 2004MY STi’s took 1st and 2nd place in Club Racing’s T2 division. ESX Motorsports announced the introduction of the WRX STI in World Challenge’s GT class in 2005.
In 2008, Cusco’s Impreza won the first GT300 race in Sepang. It marked the first AWD car victory in Super GT/JGTC history. Even though they were having very impressive results(with 1 win and 2 podiums) that season, Cusco announced that they would not participate in the 2009 season as they want \ The performance of Cusco was outstanding even though they were using a 4-door car, it later lead the Super GT committee to officially allow all 4-door model cars to participate the series. The Toyota Corolla Axio followed suit in 2009.
Subaru Impreza WRX STI Super GT Specifications (2008)
- Chassis: Tubular frames with bellhousing, integrated driver safety cell and defined front must be FIA, JAF approval.
- Engine: Custom-built Subaru EJ-20 engine, Horizontally Opposed 4-cylinder Single turbocharger, DOHC, 4-valves per cylinder.
- Engine displacement: 2.0 L (2,000 cc).
- Bodywork: CUSCO.
- Power: Over 300 bhp (220 kW; 300 PS).
- Torque: Over 40 kgf·m (390 N·m; 290 lb·ft).
- Roll cage: SAFETY21.
- Gearbox: 6-speed sequential transaxle AWD gear-box.
- Differential: Mechanical L.S.D..
- Front: CUSCO Type-RS.
- Center: 1WAY RS.
- Rear: 1WAY RS.
- Brakes: Endless.
- Clutch: EXEDY carbon 5.5in.
- Wheelbase: 2,540 mm (100 in).
- Length: 4,465 mm (176 in).
- Height: 1,430 mm (56 in).
- Width: 1,840 mm (72 in).
- Front track: 1,530 mm (60 in).
- Rear track: 1,530 mm (60 in).
- Weight : 1,150 kg (2,535 lb).
- Fuel Capacity: Approximately 16 imp gal
- Springs: CUSCO.
- Suspension arm: CUSCO pillow ball suspension.
- Damper: ZF Sachs.
- Wheels: Racing Hart CP-035 MAG 11.0J-18 (Front and Rear).
- Tires: Dunlop Direzza 280/710 R18 (F&R).
- Fuel: Moty’s.
- Oil: Moty’s.
- Fuel delivery: Injected fuel system.
- Racing seat: BRIDE Gardis CFPR.
- Seatbelt: TAKATA MPH-350R.
- Team: CUSCO/Dunlop Subaru Impreza.
D1 Grand Prix
2005: Nobushige Kumakubo is the first to use an GD-chassis WRX STi at the D1 Grand Prix series. The car is extensively modified as regulations permit only two wheel drive cars. This STi is unique in that it is the first to locate a radiator (with the fan beside it) behind the driver rather than in front of the engine compartment as other cars usually do. His other Team Orange teammates, Kazuhiro Tanaka and Naoto Suenaga, soon followed suit.
2006: Team Orange and Jun Autosports have converted a GC-chassis 2-door STi into a RWD vehicle for drifting to be used by third driver Naoto Suenaga. Drivers Nobushige Kumakubo and Kazuhiro Tanaka took a single win each during the 2006 season and the former took the overall D1GP title.
The Subaru EJ engine is a series of automotive engines manufactured by Subaru and introduced in 1989, intended to succeed the previous Subaru EA engine. The EJ series is the mainstay of Subaru’s engine line, with all engines of this series being 16-valve flat-4 horizontal, with configurations available for single-, or double-overhead camshaft arrangements (SOHC or DOHC). Naturally aspirated and turbocharged versions are available, ranging from around 120 horsepower in early non-turbo Legacies, to 320 horsepower in the Impreza WRX STI.
- Impreza GC1 series (JDM)Replaced by Subaru EL engine in 2006 GD, GG, GE & GH series (JDM) Impreza.
- Displacement: 1493 cc
- Bore: 85.0 mm
- Stroke: 65.8 mm
- Compression Ratio: 9.4:1 – 10.0
- Valvetrain: SOHC
- Fuel Delivery multi point fuel injection
- Horsepower: 97 PS (71 kW; 96 bhp) @ 6000 rpm
- Torque: 129.4 N·m (95 lb·ft) @ 3600 rpm
- Horsepower: 102 PS (75 kW; 101 bhp) @ 5600 rpm
- Torque: 136.3 N·m (101 lb·ft) @ 4000 rpm
- Horsepower: 95 PS (70 kW; 94 bhp) @ 5200 rpm
- Torque: 140.2 N·m (103 lb·ft) @ 3600 rpm
- Horsepower: 100 PS (74 kW; 99 bhp) @ 5200 rpm
- Torque: 142.0 N·m (105 lb·ft) @ 4000 rpm
- Impreza 93-94 (JDM only) GC4 series
- Impreza 93-06 (Europe & Middle East)
- Impreza 93-97 (Australia)
- Displacement: 1597 cc
- Bore: 87.9 mm
- Stroke: 65.8 mm
- Compression Ratio: 9.4:1 – 10.0:1
- Valvetrain: SOHC
- Fuel Delivery mpfi (carburetor in some locations)
- Horsepower: 100 PS (74 kW; 99 bhp) @ 6000 rpm
- Torque: 138.3 N·m (102 lb·ft) @ 4500 rpm
- Impreza 93-99 GC6 series
- Legacy (except USA) 90-96 BC2, BC3, BD2, BD3, BG3 series
- Isuzu Aska (1990–1993)
- Displacement: 1820 cc
- Bore: 87.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 9.5:1 – 9.7:1
- Valvetrain: SOHC
- Fuel Delivery single point fuel injection
- Horsepower: 110 PS (81 kW; 108 bhp) @ 6000 rpm
- Torque: 149.1 N·m (110 lb·ft) @ 3200 rpm
- Horsepower: 115 PS (85 kW; 113 bhp) @ 6000 rpm
- Torque: 154.0 N·m (114 lb·ft) @ 4500 rpm
- Horsepower: 120 PS (88 kW; 118 bhp) @ 5600 rpm
- Torque: 163.8 N·m (121 lb·ft) @ 3600 rpm
(Japanese: Subaru EJ20)
- Displacement: 1,994 cc
- Bore: 92.0 mm
- Stroke: 75.0 mm
EJ20E SOHC naturally aspirated
- Legacy JDM
- 1989-1994 125 hp (93 kW) BC – BF series
- 1993-1999 135 hp (101 kW) BD – BG series( ECU code EURO 3G,D3 ; Asia 4H)
- 1998-2004 155 hp (116 kW) BE – BH series( ECU code EURO 3G,D3 ; Asia 4H)
- 2003-2009 140 hp (100 kW) BL – BP series
- Impreza JDM
- 1993-1999 135 hp (101 kW) GC – GF series
- 2008-current 140 hp (100 kW) GH series
- Isuzu Aska (1990–1993)
- 1989-1994 125 hp (93 kW)
EJ20D DOHC naturally aspirated
- Legacy JDM
- 1989-1999 150 hp (110 kW) BC – BF and BD – BG series
EJ202 SOHC naturally aspirated
- Forester JDM SG series
EJ204 DOHC naturally aspirated AVCS
- Legacy JDM BL – BP series
- 2003-2009 190 hp (140 kW)
- Impreza JDM GC – GF series
- 1993-1999 155 hp (116 kW)
EJ20N runs on compressed natural gas
All engines listed below were installed with a turbo and an intercooler
This is not actually a valid code from Subaru, but is mostly used by enthusiasts and also mechanics to describe the entire line of 2.0 litre turbocharged engines that have been available over time. The practice began with the incorrect designation of the USA-spec turbo, commonly referred to as the EJ22T, and the habit of referring to any turbocharged engine as a “T” began. When referring to the EJ20T, one is speaking of one of the following:
EJ20G engines fall in to 3 categories:
1. Rocker-style HLA EJ20G usage:
- Legacy RS 89-93
- Legacy RS-RA 89-93
- Legacy GT 89-93
Power output ranges from 200 PS (147 kW; 197 bhp) @ 6000 rpm and 260 Nm for the GT to 220 PS (162 kW; 217 bhp) @ 6400 rpm and 270 Nm for the RS versions. Engines can be identified by coil on plug with 2 M6 bolts per coil and valve covers with 4CAM 16VALVE and horizontal lines above and below the plug holes. All these engines have the air-to-water intercooler setup (chargecooler) and Oil squirters.
2. Bucket-style HLA EJ20G usage:
- Impreza WRX 92~96
- Impreza WRX Wagon 92~96
- Impreza WRX STI 93~96
- EUDM Subaru Impreza Turbo 94~96
Power output ranges from 220 PS @ 6000 rpm and 260 Nm for the WRX Wagons to 275 PS @ 6500 rpm and 319 Nm for the WRX STI Version II. Engines can be identified by coil on plug with 1 M8 bolt per coil and valve covers with 4CAM 16VALVE and horizontal lines above the plug holes. Generally these engines all have the slanted intercooler. Some engines may not have HLA buckets but solid buckets with shims underneath. These engines also feature lighter valves, the intake valves are marked INKO and the exhaust valves are marked EXKO. The standard HLA valves are I252 and E283 respectively. All WRX Wagon engines and automatic sedan engines came with a TD04 with 90 deg elbow, all manual WRX sedans including STI versions all had a TD05 with 90 deg elbow.
3. Shim-over-bucket style EJ20G usage:
- Impreza WRX AT 97~98
- Impreza WRX AT Wagon 97~98
- JDM Forester Turbo 97~98
- EUDM Subaru Impreza Turbo 97~98
Power output is 250 PS @ 6000 rpm for the Japanese versions and 211 PS for the European model. Engines can be identified by smooth valve covers, plug leads and a wasted spark coil in the middle of the intake manifold. These engines were available with both manual and automatic transmission in Japan, but generally had manual the transmission in Europe in the Impreza Turbo.
to identify an EJ20K
- Wasted spark coil pack on center of manifold
- Inlet under manifold
- Divorced idle air controller
- Impreza WRX & STi 9/96~9/98
This engine series is used for non-Japanese marketed WRX models in the world market as of 1999. The Japanese WRX models use the EJ207 from 1999~2001, except the 5-door wagon which also uses the EJ205. After 2001, all WRXs use the EJ205, with an exception of the USDM models, which used the EJ205 until 2005. The EJ205 has a 8:1 compression ratio.
To identify an EJ205:
- Coil on plug*
- idle air integrated into throttle body
- open deck block
Usage: Impreza WRX
- 99~01 (JDM Wagon Body only)
- 01~current (all JDM)including Forester Cross Sports and STI (9:1 compression ratio)
- 02~05 (USDM)
- 2005 only SAAB 9-2X AERO
- 99~current (all other markets)
NOTE: The Australian Spec MY00 EJ205 does not have coil on plug but can be identified from the VIN of the vehicle (if known) where the 10th digit will be Y (for year 2000) and the 6th Digit will be 8 (for the 2000yr/EJ205)
The EJ207 has a 8.0:1 compression ratio.
To identify an 9/99-9/2000 EJ207
- Wasted spark coil pack off center of manifold
- Inlet under manifold
- Red intake manifold
- Semi-closed deck block
- Impreza WRX STi 1998~present (JDM, specifically Homologation models for World Rally Championship)
This can refer to one of the 2.0 Litre DOHC Sequential Twin Turbo and intercooled engines (EJ20H/EJ20R/EJ206/EJ208), yet like EJ20T, it is not actually a valid code used by Subaru themselves. Used from 1994 to 2005 in various iterations listed below. Due to the tight confines of the engine bay, the twin turbo engine was installed in Japanese-spec Legacies only, which were right-hand drive.
- 1993-1998 Legacy chassis code BD/BG5 JDM RS, RS-B and GT’s ( 183 kW (249 PS; 245 bhp) manual & automatic) and auto RS-B and GT-B’s (190 kW (258 PS; 255 bhp) automatic)
- 1996-1998 Legacy chassis code BD/BG5 JDM manual RS-B and GT-B’s (206 kW (280 PS; 276 bhp) Manual)
- 1998-2003 Legacy chassis code BE/BH5 JDM GT’s, GT-B’s and B4′s (190 kW (258 PS; 255 bhp) Auto)
- 1998-2003 Legacy chassis code BE/BH5 JDM GT’s, GT-B’s and B4′s (206 kW (280 PS; 276 bhp) Manual)
- Impreza 95-01
- Legacy 90-99, Outback 95-99
- Displacement: 2212 cc
- Bore: 96.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 9.5:1 – 9.7:1
- Valvetrain: SOHC
- Fuel Delivery multi-point fuel injection
EJ221 Naturally Aspirated
- Horsepower: 135 bhp (101 kW; 135 bhp) @ 5800 rpm
- Torque: 186.3 N·m (137 lb·ft) @ 4800 rpm
EJ222 Naturally Aspirated
- Horsepower: 142 bhp (106 kW; 144 PS) @ 5600 rpm
- Torque: 149 lb·ft (202 N·m) @ 3600 rpm
EJ22 Enhancements and Improvements
Beginning in the 1997 Model Year, the 2.2 liter engine for 1997 Legacy and Impreza models has had internal and external changes that yield an approximately 10% increase in power and 3% increase in fuel economy. Accomplishing this involves many factors, one of which is engine friction reduction. The piston, a major source of engine friction, has been coated with molybdenum to reduce friction. This thin coating not only allows smoother travel through the cylinder, but also reduces cylinder wall scuffing. The skirt of the piston has been reshaped and the overall weight has been reduced by approximately 100 grams. Compression ratio has been increased to 9.7 to 1 by reshaping the crown of the piston. This eliminates the clearance that was available between the piston at TDC and the fully opened valve. Piston pin offset has been changed to 0.5 mm (0.0 in). Piston to cylinder wall clearance has been reduced by increasing the piston diameter. Another source of high engine friction is the valve train. Hydraulic lash adjusters (HLAs) are always in contact with the valves. The hydraulic pressure of the lash adjuster must be overcome during operation and during the most critical time of engine start. To overcome this situation and to contribute to the total reduction of friction loss, 1997 and later SOHC engines have solid valve adjusters. The scheduled service of this valve train is set at 100,000 miles (160,000 km). SOHC engines now use an adjustment screw to adjust valve clearance. The roller rocker cam follower system that was introduced on the 1.8L Impreza engines, is installed on all 1995 model year and later 2.2 liter engines. The roller assemblies are not serviceable separately, but the rocker arms may be serviced as individual units. The carbon composition head gaskets with integrated o-rings are interchangeable from left to right on 1990 to 1994 N/A engines only. Other Engine Modifications (2.2L 1997) The intake manifold has been reshaped to increase the airflow mass and speed, contributing to improved low and mid engine speed operation. Components located on the intake manifold have been relocated as compared to the 1996 models. EGR Solenoid, Purge Control Solenoid, etc. 1999 2.2 Liter Phase 2 Engine Enhancements (from endwrench article H-4 and H-6 service): All 2.2 liter engine for 1999 are the Phase 2 design. The 2.2 liter Phase 2 engines are a SOHC design, with a newly designed cylinder head. Changes in the 2.2 liter Phase 2 engines are as follows:
- The engine and transmission are fastened with six bolts and two studs.
- The thrust bearing has been moved to the number 5 position.
- The oil groove in the number 1 and 3 have been changed to supply additional lubrication to the crank journal.
Additional Phase 2 Engine Features
- The cylinder head is a two-rocker shaft, solid type valve system with roller followers.
- The valves are positioned at a larger angle than previous model years. The intake valves are positioned 23 degrees off-center with the exhaust valves positioned 20 degrees off-center. Prior model year engines utilized a 15-degree positioning angle.
- Head gasket thickness is 0.7 mm (0.03 in).
- The intake rocker arms are marked so they are correctly placed on the rocker shaft when servicing. An IN1 or IN2 will be embossed on each rocker arm. As viewed from the front of the engine the Number 1 intake valve of ach cylinder and the number 2 intake valve have an IN1 marked and IN2 arked rocker arm that mates with it. New IN1 rocker arms can also be identified by a Green painted mark on the top of the rocker arm. The IN2 rocker arms have a white mark. Proper positioning is maintained through the use of a wave washer located between the rocker shaft arm and rocker arm shaft support.
- The camshaft is secured to the cylinder head with the camcase. An oil passage in the cylinder head provides the passageway in the camcase with oil that leads to the intake rocker shaft. Oil from the camshaft is collected on the opposite side of the passageway leading to the intake rocker shaft to provide oil to the exhaust rocker shaft.
Note: Cylinder head and camcase must be replaced together (line bored).
- The sparkplug pipe is pressed into the cylinder head and is not serviceable.
If it becomes damaged the cylinder head must be replaced. The seals installed onto the ends of the sparkplug pipes seal against the valve covers and should be replaced when the valve cover is removed.
- Pistons on the 2.2 liter engines have a 0.5 mm (0.0 in) offset with the engine having a compression ratio of 10.0 to 1. The horsepower has increased to 142 hp (106 kW) @ 5600 rpm. Maximum torque is 149 lb·ft (202 N·m) @ 3600 rpm.
- Camshaft sprockets are constructed of a resin type material with a metal key pressed into the sprocket for maintaining proper sprocket to shaft orientation.
135 bhp (101 kW) @ 5800 rpm 140 lb·ft (190 N·m) @ 4800 rpm Australian model – 100 kW (130 hp) @ 6000 rpm 189 N·m (139 ft·lbf) @ 4800 rpm Usage:
- Legacy 90-96
- Impreza 93-97
Phase one 2.2 Liter SOHC Turbo, 163 bhp (122 kW; 165 PS) fully closed deck, oil squirters, no intercooler
- Legacy 1991-1994 (North American-spec)
Phase two 2.2 litre closed deck
- Displacement: 2212 cc
- Bore: 96.9 mm
- Stroke: 75.0 mm
- Compression Ratio: 8.0:1
- Valvetrain: DOHC
- Fuel Delivery multi point fuel injection
EJ22G Turbo DOHC
- Horsepower: 280 PS (206 kW; 276 bhp) @ 6000 rpm
- Torque: 362.8 N·m (268 lb·ft) @ 3200 rpm
- Impreza STi 22B GC8 series(JDM)
- Legacy STi BF7 and BFB series wagon (JDM)
- Displacement: 2457 cc
- Bore: 99.5 mm
- Stroke: 79.0 mm
- Compression Ratio: 9.5:1 – 10.0:1 Naturally Aspirated
- Compression Ratio: 8.0:1 – 9.5:1 Turbo
- Fuel Delivery multi point fuel injection
DOHC (1996) – SAE – 155 hp (116 kW) @ 5600 rpm
140 ft·lbf (190 N·m) at 2800 rpm
DOHC (1997–1999) – SAE – 165 hp (123 kW) @ 5600 rpm
162 ft·lbf (220 N·m) at 4000 rpm
- Impreza 98
- Legacy/Outback 96~99
- Forester 98
Power ISO: 123 kW (165 hp) @ 5600 RPM
226 N·m (167 ft·lbf) @ 4000 rpm
- Impreza 2.5RS, 2.5TS 00-04 (US)
- Impreza Outback Sport 02-04 (US)
- Forester 00-04 (US)
- Legacy 00-04 (US)
- Outback 00-04 (US)
- Baja 03-05 (US)
SOHC Power ISO 115 kW (156 hp) Usage:
- Legacy/Outback 00
- Forester 00
SOHC - ISO 173 hp (129 kW) @ 5600 rpm, 166 ft·lbf (225 N·m) torque @ 4000 rpm. Intake volume is regulated by use of a MAF sensor, unlike the EJ251 which is regulated by a MAP sensor. I-Active valves (VVL intake side) on 06+ models.
- Impreza 99, 05+
- Legacy, Outback USA 05+
- Forester 99, 05+
- Baja 05+
- Saab 9-2x Linear 05, 06
SOHC 16-valve Power SAE 121 kW (165 hp), 2005–present – 175 hp (130 kW).
- Impreza RS 02~04
- Forester 04
- Legacy/Outback 02~04, 05-present
- Legacy Lancaster RHD 1999-2003
DOHC turbocharged, with sodium-filled valves originally designed for North American market, now sees usage in some European Imprezas and Legacies destined for Australia and South Africa. Power 210-265 hp
Usage in North America:
- Impreza: 2006–present
- Forester: 2004–present
- Legacy: 2005–present
- Outback: 2005-2009
- Baja: 2004 – 2006
- SAAB 9-2X: 2006 only
Usage in the rest of the world:
- Legacy/Outback: 2007–present
- Impreza: 2006–present
- Forester: 2005–2010
- US Market Impreza WRX STi MY04~MY07 (300 hp, 293 hp (New SAE standard))
- US Market Impreza WRX STI MY08~MY10 (305 hp (New SAE standard))
- US Market Subaru Legacy/Subaru Outback MY05~MY06
- Asian, European Market Impreza WRX STi 05~present (280 hp, 40KGh/m)
- JDM Forester STI MY05~present
Subaru Formula One Flat-12
In 1990, Subaru took over the Coloni Formula One team, acquiring a 51% ownership stake, paying off the team’s debts, and supplying a new, unique engine. The engine was a flat-12 called the “MM” series, which in fact was penned by Carlo Chiti.
Chiti’s Motori Moderni company at Novara had supplied V6 turbo engines for the Minardi Formula One team from 1985 to 1987, and in 1988 Chiti had penned a normally aspirated V12 engine that attracted Subaru. In late 1988, the Japanese commissioned Chiti to design a new Formula One engine with a “flat” layout, as used in their road cars. The engine was completed in the summer of 1989, and was tested in a Minardi M188 chassis; due to a severe lack of power, Minardi lost interest. After a few months of searching, Subaru found the Coloni team. Eventually, the Subaru Coloni team was founded with Enzo Coloni staying on board as the man for operational business.
By the beginning of 1990, the Subaru flat engine was not producing more than 500 bhp, so the Coloni Subaru was by far the least competitive machine regularly competing in Formula One in 1990. Subaru and Chiti agreed to build a new V12 engine for summer 1990 together with a completely new chassis, but in the meantime the flat engine should be used by the Coloni Subaru Team in a carry-over chassis. Early in 1990, a handful of Enzo Coloni’s mechanics worked on a single C3 and tried to put the Subaru engine in it. The work was not done until the day the FIAstarted shipping the Formula One material to Phoenix. In the pits at Phoenix, the car was assembled for the very first time, and a short private practice took place on a parking area of an American supermarket. On prequalification day of Phoenix the world saw Coloni’s new model C3B which wore a white, red, and green livery. Without an airbox but with wide, long sidepods, it looked unusual, was overweight by 300 pounds and nearly impossible to handle. Bertrand Gachot, Coloni’s new driver, was unable to prequalify the car at Phoenix or at any other event. As the season went on, improvements were few and results stayed nowhere. Meanwhile, no success could be seen at Coloni’s plant in Perugia where obviously nobody worked seriously on a new car. In May, Enzo Coloni was sacked by Subaru, but no improvement came. In June, the Japanese company withdrew completely and sold the team back to Enzo Coloni, debt free, but with no sponsors and no engines. By the German Grand Prix Coloni had arranged a supply of Cosworth engines, prepared by Langford & Peck. An improved car also appeared in Germany. The new Coloni C3C was simply a 1989 C3 with minor changes in aerodynamics. The car was quicker, but not enough to achieve any serious results. Gachot was usually able to prequalify his car, but the main qualification was still out of reach. By the end of the season, Coloni had not taken part in a single Grand Prix.
All the EJ series share compatibility and construction similarity and are 16 valved engines. The EJ series started with the EJ15, a 1.5 liter (SOHC) and makes ~90 hp, then the EJ16, a 1.6 litre single overhead cam (SOHC). Later followed by the EJ20, a 120 hp 2.0 litre single overhead cam and the EJ22, a 135 hp 2.2 litre single overhead cam. The EJ20 turbocharged version was developed with dual overhead cams, as well as non-turbo DOHC engines and DOHC twin-turbos. The EJ18 and EJ20 were most popular in Europe and the EJ22T SOHC, mostly in the US and is known as the “bulletproof Subaru engine.”
The SOHC EJ Subaru boxer engines were non-interference engines through 1996, run by a single timing belt driving both cams (both sides of the engine) and the water pump. Because they are non-interference engines, if the timing belt fails, the engine of the models up to 1996 will not be destroyed. The oil pump is driven directly from the crank shaft and the waterpump by the timing belt. All DOHC and 1997-up SOHC EJ engines are interference engines, if the timing belt fails the engine will likely be destroyed or the valves & piston will be heavily damaged.
All Subaru EJ engines have a 1-3-2-4 firing order.
Some of the 2005 and later Subaru vehicle Engines (especially the turbo charged engines) are using CAN (Controller Area Network) bus as their sole Vehicle/Vessel speed input channel, the CAN bus normally runs at 500K baud rate. When those ABS Speed signal are removed, the ECU will force the Engine running at limp home mode (engine cannot run over certain speed, maximum power and torque output are limited, and idle is not as stable as normal operation). This has posed some challenge for people who try to use the same automotive boxer 2.5L and 3.3L engines on Aerospace application, engine replacement for aged Subaru vehicles, and VW Vanagon modifications, etc.
The following table has details on a few of the commonly modified Subaru engines:
|Head Type||US STI Heads||US WRX Heads||SpecC Heads||US WRX Heads||SpecC Heads|
|Piston Pin Offset||(mm)||30.88||30.88||30.88||32.89||31.59|
|Total Quench Height||(mm)||0.99||0.99||0.99||0.98||2.08|
|Total Quench Volume||(cc)||7.70||7.70||7.70||8.51||13.83|
|Total Deck Volume||29.70||29.70||29.70||18.51||19.83|
|Rod to Stroke Ratio||(na)||1.65||1.65||1.65||1.74||1.74|
Subaru 2.5-liter Turbo Boxer Engine won ‘best engine’ in the 2.0-2.5 litre category in both the 2006 and 2008 International Engine of the Year awards.[