Subaru Impreza WRX STI
Manufacturer	Subaru
Parent company	Fuji Heavy Industries
Production	1992–present
Assembly	Ota, Tokyo, Japan
Class	Sport compact World Rally Car Sports car
Layout	Front engine, four-wheel drive

The Subaru Impreza WRX STI (formerly STi, officially changed in 2006) is the highest standard-edition trim in the Subaru Impreza compact car line, produced by Japanese automaker Subaru.

In the late 1980s, Subaru created the Subaru Tecnica International (STI) division to coordinate development for the FIA World Rally Championship and other motorsports activities. After the company had grown, the division was used to create high-performance consumer versions of the Subaru Impreza WRX, an all-wheel drive car with a turbocharged flat-4 engine, leading to the development of the Impreza WRX STi. Subaru has used a race-prepared version of the WRX STI as its rally platform since the model trims creation.

GC chassis (1992 - 2001)

GC
Production	1992-2001
Body style(s)	2-door coupé 4-door sedan 5-door station wagon
Engine(s)	2.0 L H4
Wheelbase	99.2 in (2520 mm)
Related	Subaru Impreza Subaru Impreza WRX Subaru Forester

There were six noted versions of the STi. The different versions were marketed with consecutive numbers. Another way to tell the version of a WRX STi was to look at the chassis code. All WRX STis have the beginning chassis code of either GC8 (sedan or coupé) or GF8 (station wagon), followed by a letter from A to G. There was a GC chassis version of the RS released in 2001 as well in the United States.

 

Japanese-spec

 

Version I (10/92 – 08/94) - GC8A/B

The first STi was known simply as "STi" (there was no "version" moniker added to the name until the version II). An unknown quantity was manufactured from February of 1994. In March, production was stabilized to 100 STis a month. It had 250 PS (184 kW) @6500 rpm and 31.5 kgf·m (309 N·m) @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 of 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) produced 275 PS (202 kW) and 32.5 kgf·m (319 N·m) 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 (09/95 – 08/96) - GC8C

The regular STis engine output stood at 275 PS (202 kW) and 32.5 kgf·m (319 N·m) of torque. This was the year that STi started painting the intake manifold red. The car weighed 1240 kg (2734 lb) and had gold rims like the one on the World Rally Championship Impreza.

The V-limited STi edition was produced. It was a limited edition was often used to celebrate a Manufacturer or Driver title award to Subarus 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. ra was race altered

 

Version III (09/96 – 08/97) - GC8D

The engine was vastly updated and was given the name Boxer Master 4. It developed the then-established gentlemens agreement power limit of 280 PS (276 hp/206 kW). Torque peaked at 4000 rpm with a value of 35.0 kgf·m (343 N·m). Standard this version has a top speed of over 300km. The car gained 10 more kilograms and weighed at 1250 kg (2756 lb). The STi shared the same face lift that the rest of the Impreza line received.

With Version III came the start of the coupe version of the WRX STi. This car was to be the new basis for rally races. It is called the WRX Type R STi. The coupe was chosen by Prodrive because it was smaller, lighter and stiffer than the 4 door version. It was essentially a 2 door version of the WRX Type RA STi meaning it had DCCD, little sound-insulating material, close-gear ratios and the gearbox was hardened. This car also has a water-spray nozzle to dampen the top of the intercooler. The water will then evaporate, which takes heat away from the intercooler and cools the intake charge. This car was produced on an order-only basis.

Also there was WRX STI type RA (4 door) available in Version 3, they have the same motor, gearbox and r160 diff as the Version 3 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 1190 kg (2624 lb). The DCCD has been known to bite new drivers in the wet. The RA gets a roof vent instead of map lights, Also wind up windows, although electrics are an option from factory.

Also available was a WRX Type R V-limited, in version 3. It has a WRX motor - no forged internals like the STI, and it misses out on the 4 pot front brakes (as these parts are removed and replaced in a rally fit out) but it has a roof vent and is lightweight. A good base for a rally car.

Version 3 STI runs a VF23 IHI ball bearing turbocharger, The JDM non Sti gets a VF22

 

Version IV (09/97 – 08/98) - GC8E

Power was increased to 280 PS (276 hp/206 kW), and torque was increased to 36.0 kgf·m (353 N·m).

Again, like the Version II, there were 555 WRX Type RA STi Version 4 V-limited cars produced. The WRX Type R STi Version 4 V-limited was produced on an orders-only basis with a 3 month waiting period.

 

Version V (09/98-08/99) - GC8F

The power stayed the same as the previous version. 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 been applied to the STis as well. The WRX STi weighed 1270 kg (2800 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.

 

Version VI (09/99-08/00) - GC8G

GC8G
Production	1999-2000
Body style(s)	2-door coupé 4-door sedan 5-door station wagon
Engine(s)	2.0 L H4
Wheelbase	99.2 in (2520 mm)

Again the power stayed the same. Most of the changes were cosmetic. The wing was sculpted to be more aggressive.

There were 2000 WRX STi Version 6 Limited, 1000 WRX Type R Version 6 Limited and 2000 WRX STi RA Version 6 Limited cars produced.

 

Japanese-spec 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 Subarus 40th anniversary as well as the 3rd consecutive manufacturers title for Subaru in the FIA World Rally Championship. On the release of the sales, all 399 sold out from 30 minutes to 48 hours, depending on the report. The cars had the starting VIN code of GC8E2SD. Another 25 were produced for export markets - see the 22B Type UK below.

The 22B had the EJ22 engine as opposed to the regular EJ20 engine. 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 (276 hp/206 kW) at 6000 rpm and 363 N·m (268 ft·lbf = 37.0 kgf·m) of torque at a lower engine speed of 3200 rpm. The redline was lowered from 8000 rpm to 7000 rpm. The compression is a 8.0:1. The turbocharger is an IHI RHF 5HB (the internal company usage code is VF22).

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 cars curb weight is 1,270 kg (2,800 lb). The suspension is provided by Bilstein. The brakes were standard 4-piston/2-piston brakes. However, the color is red and the Subaru name casted on the brake calipers are painted white. The wheels were increased in size from the standard WRX Type R STi from 16" x 7" to 17" x 8.5" BBS 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, 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.

It must be noted that 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 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 going to David Lapworth of Prodrive.

 

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 (276 hp/206 kW) (special variant cars were excluded from the gentlemens 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.

 

UK-spec Special Variants

 

22B Type UK (1998)

16 of the export 22Bs (see above) were modified by Prodrive, with longer gear ratios, UK lights and driving 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 Single Vehicle Approval scheme. The price was £39,950, which was roughly what grey import 22Bs were going for.

 

P1 (2000)

To counter the grey imports of high-performance Japanese variants, Subaru UK commissioned Prodrive to produce an official limited edition of 1000 two-door cars in Sonic Blue. The chassis was a 2 door coupe. They were taken from the STI Type R lines and used for the P1. The car was the only coupe 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), and the suspension optimised for British roads. Options were available from Subaru consisting of 6 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.

 

GD chassis (2002 - 2008)

GD
Production	2002-2008
Body style(s)	4-door sedan 4-door station wagon
Engine(s)	2.5L H4
Transmission(s)	6-speed manual
Wheelbase	2004-05: 100.0 in (2540 mm) 2006-08: 99.4 in (2525 mm)
Length	2004-05: 173.8 in (4415 mm) 2006-08: 175.8 in (4465 mm)
Width	68.5 in (1740 mm)
Height	56.3 in (1430 mm)

In 2001, 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 transmission (reputed to be one of the cars 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 turbochargers are IHI models. The interior was updated with a STi logo on the gauge. The STis gauge also has a red shift light. The STis and optioned Type RA STi have received Brembo 4 pot front and 2 pot rear brakes while the bare-bones Type RA STi still carried the Subaru 4 pot front and 2 pot rear brakes. Externally, the STis had larger hoodscoops and had foglight 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) where as the regular WRX had an A). The forth charter of the VIN gives the revision (A to F where G is the current (2007) version).

 

Japanese-spec

 

Rev. A (2001)

In 2001, 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 260 PS (191 kW). 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 grill 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 Cs 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 Teams Group N driver Toshi Arai.

The WRX STi was used for Group N homologation.

 

Rev. E (2005)

The WRX STi receives the same increase in wheelbase as the Spec C. All 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 mm to 5 x 114.3 mm.

 

Rev. F (2006)

The WRX STI continues on relatively the same. The Impreza lines looks have been updated.

The WRX STI Spec Cs 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 cars 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.^[5]

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 slightly larger turbo (VF43, as opposed to VF39 in the older version) and revised gearing on the 6 speed manual transmission.

 

Japanese-spec Special Variants

 

S202

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 black seats with red STi logo stitching. A smaller, lightweight AC compressor was fitted to save weight. The brake rotors were gas slotted. The rims were STi labeled Rays Volks rims.

 

S203

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 shod with custom made 18 inch BBS rims with Pirellis. The crankshaft is balanced by hand

 

S204

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 grill from the rest of the Impreza line. The S204 has a two-litre (EJ20) engine capable of developing 235 kW (or 320 hp) 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 6000 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 on an already low suspension set up plus the use of low-profile Pirelli P Zero (Corsa) tyres implies the S204 is intended mostly for sealed road use.

 

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, STI-branded, Enkei-made, white wheels. The engine has been blueprinted and balanced. It produces 320 PS (316 hp/235 kW) of power. The suspension is stock full of the latest STI parts from the STI catalogue. The front brakes are 6-piston brembo brakes. 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".

Checkout car at these sites.

http://www.autoblog.com/2006/11/08/rallylicious-subaru-wrx-sti-spec-c-type-ra-r/

http://www.nihoncar.com/review-438-X.html

http://www.subaru-sti.co.jp/ra-r/

 

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 rims, a black STI front lip and leather seats in order to target the more mature market.

 

Asia, Oceania and European-spec

In 2001, 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 (261 hp/195 kW) to 280 PS (276 hp/206 kW) 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.

In 2006, the model was facelifted like all STIs and the engine was changed to the EJ257 producing 280 PS (276 hp/206 kW).

Subaru Impreza WRX STI 2006 - front (Australian-spec)	Subaru Impreza WRX STI 2006 - rear	Subaru Impreza WRX STI 2006 - engine	Subaru Impreza WRX STI 2006 - interior driver side
Subaru Impreza WRX STI 2006 - interior driver seat	Subaru Impreza WRX STI 2006 - rear badge

 

UK Special Variants

 

WR1 (2004)

A limited edition of 1000 Japanese MY04 WRX STIs 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 316 bhp (236 kW), Prodrive WRX STI springs, Pirelli PZero Nero tires, mesh grilles, Ice Blue metallic paint and Prodrive PFF7 Pewter wheels. The new ECU and exhaust were not EU homologated, so had to be fitted after registration of the car. Price was £29,995.

 

Spec D (2006)

A Discrete version of the STI was made for a more conservative market. It is similar to the Japanese-spec A-Line except it had regular WRX spoiler on the boot, silver wheels (not Gold) and removal of the rear roof vane,it has projector fog lights Smartnav with touch screen operation (1 years free subscription), Tracker (1 years free subscription),and safe speed as standard although this was only free for the first month (subscription after that). A Pioneer DEH-P70BT sound system with an output of 200 W and a plug in I` Pod adapter is also standard., with Bluetooth phone connection. along with leather trim to seats and doors Auto climate control was also standard. It was limited to a run of 300 cars in one colour only, that was Crystal Grey Metallic so therefore is rarer than the RB320 that that had a run of 320 cars. Power on this model is rated at 280 bhp (209 kW). It has a 0-60 time of 5 seconds and a top speed of 158 M.P.H. It sold for £28,450.

 

RB320 (2007)

Echoing the RB5, a limited edition of 320 2007MY cars in Obsidian Black Pearl were released "in memory of Richard Burns", an ex-Subaru World Rally driver who had died in 2005 due to a brain tumor. The car produces 320 PS (316 hp/235 kW) of horsepower and 450 N·m (332 ft·lbf) 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 shift knob. The car has silver mesh grilles. The price is £29,995 on the road.

 

UK Unofficial Variants

 

Litchfield Type 25 (2004)

Litchfield Importsinitially imported Japanese Spec C cars into the UK. 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 car as fast as the Spec C. So he imported EJ257 engines from the US, got Powerstation to modify them to produce 350 bhp (261 kW), and then dropped them into a Japanese STI. The suspension was upgraded with AST Sportline I adjustable coilovers and Whiteline stabilizer bars and anti-lift kit to cope better with British roads. The May 2004 edition of EVO [4] called it the Best Impreza Ever when tested against the WR1, Spec C and P1.

 

Litchfield Type 25 (2007)

The new Type 25 is based on the 2007 Spec C, but the engine block and heads has been developed by Cosworth US to give 415 bhp (309 kW) and 420 ft·lbf (569 N·m), for a power/weight ratio greater than a Porsche 997 Turbo. The car can be ordered with optional Porsche brake system.

 

US-spec

 

Rev. D (2004)

In 2004, Subaru of America announced it will sell the WRX STi. Subaru Tecnica Internationals president said in an interview with Road & Track magazine that he wishes to beat the Mitsubishi Lancer Evolution in the US. Thus, each iteration of the US-spec WRX STi was essentially the same as the respective J-spec STi Spec C. All the part numbers match up, including the part-numbers for the glass windows and dampeners. 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 cast pistons as opposed to the forged pistons in the EJ207. The steering rack is the standard STis 15.2:1 instead of the Spec Cs 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.

 

Rev. F (2006)

The US-spec STIs receive the same facelift as the Japanese-spec STIs. Mechanically speaking, the DCCD 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 cars cabin. On the largest Impreza forum, North American Subaru Impreza Owners Club, 2006MY owners have had issues with these plastic engine mounts. The manufacturer will replace them, under warranty, if broken, with the 2005MY rubber and metal mounts. Later 2006MY vehicles were equipped from the factory with 2005MY 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 2006MY STI weighs approximately 3350 lb (1520 kg).

 

Rev. G (2007)

In 2007, a number of small changes were made to the US-spec model. Due to Subarus decision to reduce costs by cutting the amount of aluminum used, the US-spec STI no longer receives the J-spec Spec C control arms. The control arms are now the aluminum ones used on the Japan-spec revision A and B non-Spec C STis. The high caster angle has been reduced, which in turn reduces the wheelbase from 100" to 99.4". The rear sway bar has decreased in size from 20 mm (0.8 in) to 19 mm (0.7 in). The gear ratios of second, third and fourth gears have been made longer (higher ratio) in order to improve fuel economy and driveability, which inadvertently reduces 1/4 miles drag racing times due to the ability to trap 114 mph (183 km/h) in 4th gear, without the shift to 5th. The EJ257s cylinder heads have been redesigned to improve cooling, and the sodium-filled exhaust valves have been deleted. The alternator is changed from a 90A rating to 110 amps. The rear LSD is now a Torsen unit, considered an upgrade over the previous models helical unit. The turbo has also been changed to the VF43, which has a slightly larger wastegate than the VF39. The side cowl braces are stiffer than the 2006MY. The engine mounts are once again the hard rubber mounts used prior to 2006. On the interior, there is an audio jack that replaces the ashtray, a rear center armrest with trunk pass-through and a 120W audio system.

The WRX STI Limited is introduced. It is similar to the Japan-spec 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

 

Pros

Subaru claims that the GD chassis is 148 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. The GC chassis is so weak compared to todays cars that engineers called the body a "Watermelon frame", referring to how a watermelon shatters on impact.

In terms of safety, the GD chassis scored much higher than the GC chassis and earned a "Good" rating (highest mark) from the IIHSs 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.

 

Cons

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 countries 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 1260 kg (2778 lb), was lighter than the concurrent 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.

The author mentioned above also notes that the Jaws of Life need to cut the Subarus B-pillars at certain points in order to cut through the car frame. This information was not as widespread before, so there have been many incidences where firefighters could not cut the B-pillars due to their structural integrity. To some people, this might be a concern if the driver or passengers need to be cut out of the vehicle quickly.

 

GE chassis (2008-)

GE
Production	2008-
Body style(s)	5-door hatchback
Engine(s)	2.5L 320 hp (239 kW) H4
Wheelbase	103.1 in (2619 mm)

While the 2008 Impreza WRX was officially unveiled at the 2007 New York Autoshow, currently very little information is publicly known about the new STI. The STI will receive a higher degree of parts to differentiate it from its Impreza WRX brethren. Unlike the Impreza WRX, the STI will use aluminum body panels, will be available only as a 5-door hatchback, and will have different fenders than that of the WRX (breaking with previous tradition). Apparently, a Subaru rep stated to an IWSTI.COM member that the new STI would be 8.5" wider than the new WRX, and that power output would be at least 320 HP coming from a Legacy GT-derived 2.5L motor. According to leaked documents posted on NASIOC.com, the Impreza WRX STI will be sold to public starting January 2008 as a 2009 model. At the New York Autoshow, a Subaru spokesman confirmed that the Impreza WRC will be based off the hatch platform.

The car will appear on its definitive version at the 2007 Tokyo_Motor_Show. Subaru has released official photos on 2007/10/11 [[5]]. A final announcement is scheduled for 2007/10/24. From what is now know the car will have a 300 HP engine (2.0l twin-scroll turbo in Japan, 2.5l single-scroll turbo elsewhere).

Official Japanese site: http://www.subaru.jp/impreza/wrx_sti/index.html

American site: http://www.subaru.com/sub/misc/2008/autoshow/ny0311/wrx/index.html

 

Motorsports

 

Rally

 

FIA PCWRC

The STi serve as the basis from which Group N "production" rally cars are constructed. Group N4-classed (marketed by FIA as Production Car World Rally Championship or PCWRC) cars are the major support category for the World Rally Championship and are the premier category in many national rally championships. For the past two years (2004 and 2005), the WRX STi has taken the top 3 podiums in Group N. This new effort can be attributed to STis increased support in Group N motorsports.

 

FIA WRC

In 1995, 1996 and 1997 World Rally Championships, Subarus World Rally Team, in conjunction with Prodrive won the WRC manufacturers title with the World Rally Impreza. The STis 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 drivers title with the World Rally Impreza.

 

Rally America

2006: Travis Pastrana drove a 2006MY STI to capture the national title overall, as well as in the open class. Several other teams entered driving STIs.

 

Autocrossing

 

JAF Events

2004: The STi Spec C won 1st place in the All Japan gymkhana (Japanese autocrossing) championships.

 

SCCA Events

As of 2006, all GD-chassis STIs can compete in A Stock (AS), Street Touring Ultra (STU), B Street Prepared (BSP) and Street Modified (SM).

2005: At the Tire Rack SCCA Solo Nationals in Topeka, Kansas, 2004 US-spec STis took 1st in the STU, driven by Brandon Burkhart, and ESP classes.

2006: At the Tire Rack SCCA ProSolo in Topeka, Kansas, Jonathan Roberts drives a 2005 US-spec STi, fitted only with the Strano hollow 32 mm (1.3 in) front swaybar, to first place in AS. In STU class, Max Hayter (2006MY) and James Balducci (2005MY) drive to first and third place, respectively. At Solo Nationals, Brandon Burkhart drives a 2004 US-spec STi to a first place in STU.

 

Road racing

 

FIA Events

2005: Prova Racing 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 setup 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.2005MY WRX STI Spec C in 24 Hour Nürburgring

2006: Autosportif Racing UK campaigned a Subaru factory supported WRX STI Spec C in the 24 Hour Nürburgrings 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. It was pushing 400 horsepower (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. It had suffered 2 turbocharger unit failures during the course of the race. The car was driven by Alan van de Mewre (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).2006MY WRX STI Spec C in 24 Hour Nürburgring

 

JAF Events

2002: Eifel Prova Racing took 1st place in Japans Super Taikyu.

2005: Prova Racings STis finished the season in 1st and 3rd place in Super Taikyu.

 

SCCA Events

2005: In Club Racings T2 division, Icy Racings 2004MY STis took 1st and 2nd place. ESX Motorsports announced the introduction of the WRX STI in World Challenges GT class.

2006: Icy Racings 2006MY STIs took 1st and 2nd place.

 

Super GT

The Cusco team have been campaigning a heavily modified STi with rear drive conversion as required by regulations since the late nineties and having no two door model available at present, is the only team to be permitted to race a four door model in the series.

2006: Cuscos WRX STI now uses AWD with a transaxle gearbox.

 

Drifting

 

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. Unlike newer models who struggle throughout the season, the GD would have things better when both Kumakubo and Tanaka took a single win each and the former took the D1GP title.

 

Availability

The STI was originally sold only in Japan. It was later made officially available in Oceania (Australia had it in 1999 with the STi Version V). In 2001, Europe received the STi with the change of the chassis. After seeing the Impreza WRX sell at much better levels than expected, Subaru began selling the STI in North America in the spring-summer of 2003 as a 2004 model.

It should be noted that the Oceania and Europe actually had WRX STis in the region before the official versions. Car importation laws in those areas are much less rigid than Americas laws. Thus, the grey markets has many earlier versions of the WRX STi. In most cases, the only way to legally import an earlier version of the WRX STi than the one offered is by registering it as a race or exhibition car. However, there is a 15 year rule that allows any car at least 15 years old to be imported into Canada.

Five (5) WRX STI S204 were made available to Subaru enthusiasts in New Zealand. However, unlike other S204s sent to other nations these five did not display either the in-cabin or in-enginebay 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 (and hence availability, rarity, and value).