The Subaru Impreza WRX STI (often referred by auto-enthusiasts as simply STi; in 2006, the acronym had the 'I' capitalized; hence it is currently STI) is the highest trim in the Subaru Impreza line (excluding the limited edition special cars).
Subaru used the WRX as the basis for its World Rally car in the FIA World Rally Championship. Subaru created Subaru Tecnica International to handle its motorsports activities. After the company had grown, it was used to make highly-tuned high-performance versions of the Subaru Impreza WRX, a 4WD sportscar with a turbocharged flat-4 engine.
GC chassis (1992 - 2000)
There were 6 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 GC8 then followed by a letter from A to G.
Version I (1994) - GC8A/B: The first STi had 250 PS (184 kW) @6500 rpm and 31.5 kgf·m (309 N·m) @3500 rpm and weighed 1230 kg (2,710 lb). This version 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 Type RA (Rally Applicant) STi 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. This allows the amount of torque sent to the front and rear wheels vary from a split of 35/65 to 50/50. The DCCD would be beneficial to people who used it in various rally conditions.
Version II (1995) - GC8C: The regular STi's 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 exhaust manifolds red. The car weighed 1240 kg and had gold wheels 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 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 primier sponsor of the Subaru World Rally Team) WRX Type RA STi Version 2 V-limited were produced.
Version III (1996) - GC8D: The engine was vastly updated and was given the name Boxer Master 4. It developed the then-established gentlemen's agreement power limit of 280 PS (206 kW). Torque peaked at 4000 rpm with a value of 35.0 kgf·m (343 N·m). The car gained 10 more kilograms and weighed at 1250 kg. 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 had an intercooler spray to cooler the intake charge for the turbocharger. This car was produced on an order-only basis.
The WRX Type RA was not produced and there were only 500 of the WRX STi Version 3 V-limited produced.
Version IV (1997) - GC8E: The power was again increased. This time 280 PS (206 kW) was produced, but the 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 (1998) - GC8F: The power stayed the same as the previous version. The engine layout and design was made cleaner. This engine was dubbed as the Boxer Phase2 engine. The facelift the rest of the Impreza line also applied to here. The WRX STi weighed 1270 kg.
There V in "V-Limited" was dropped. 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 (1999) - GC8G: Again the power stayed the same. Most the changes were cosmetic. The wing was sculpted to be more aggressive.
There were 2000 WRX STi Version 6 Limited and 1000 WRX Type R Version 6 Limited cars produced.
Japanese-spec Special Variants
22B STi (1998): In 1998, Subaru of Japan produced a widebody, 2-door, Impreza called the 22B STi. The 22B had the EJ22 engine as opposed to the regular EJ20 engine. This means the displacement was increased from 1994 cc to 2212cc. The block was a closed-deck borrowed from the Legacy's EJ22. The heads (valves, valvetrain and such) were lifted from the STi Version 4 engine. It produce 280 PS (206 kW) and 363 N·m (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 22B was used to commemorate the 3rd consecutive manufacturer's title for Subaru in the FIA World Rally Championship. This car was given a unique color of blue and had fender flared widebody taken from the Peter Stevens designed WRC car. It sported a Bilstein suspension, a triple-plate clutch, cryo-treated gears, a unique spoiler, a unique bumper and custom BBS gold wheels.
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 on the WRC car as 22B is a hexadecimal representation of the decimal number, 555.
It is interesting to note that the 22B STi that is suppose to be #13 was never given the plaque. Subaru of America imported #13 to be used as a press car.
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 (206 kW) (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.
Subaru used the WRX as the basis for its World Rally car in the FIA World Rally Championship. Subaru created Subaru Tecnica International to handle its motorsports activities. After the company had grown, it was used to make highly-tuned high-performance versions of the Subaru Impreza WRX, a 4WD sportscar with a turbocharged flat-4 engine.
GC chassis (1992 - 2000)
There were 6 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 GC8 then followed by a letter from A to G.
Version I (1994) - GC8A/B: The first STi had 250 PS (184 kW) @6500 rpm and 31.5 kgf·m (309 N·m) @3500 rpm and weighed 1230 kg (2,710 lb). This version 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 Type RA (Rally Applicant) STi 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. This allows the amount of torque sent to the front and rear wheels vary from a split of 35/65 to 50/50. The DCCD would be beneficial to people who used it in various rally conditions.
Version II (1995) - GC8C: The regular STi's 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 exhaust manifolds red. The car weighed 1240 kg and had gold wheels 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 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 primier sponsor of the Subaru World Rally Team) WRX Type RA STi Version 2 V-limited were produced.
Version III (1996) - GC8D: The engine was vastly updated and was given the name Boxer Master 4. It developed the then-established gentlemen's agreement power limit of 280 PS (206 kW). Torque peaked at 4000 rpm with a value of 35.0 kgf·m (343 N·m). The car gained 10 more kilograms and weighed at 1250 kg. 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 had an intercooler spray to cooler the intake charge for the turbocharger. This car was produced on an order-only basis.
The WRX Type RA was not produced and there were only 500 of the WRX STi Version 3 V-limited produced.
Version IV (1997) - GC8E: The power was again increased. This time 280 PS (206 kW) was produced, but the 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 (1998) - GC8F: The power stayed the same as the previous version. The engine layout and design was made cleaner. This engine was dubbed as the Boxer Phase2 engine. The facelift the rest of the Impreza line also applied to here. The WRX STi weighed 1270 kg.
There V in "V-Limited" was dropped. 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 (1999) - GC8G: Again the power stayed the same. Most the changes were cosmetic. The wing was sculpted to be more aggressive.
There were 2000 WRX STi Version 6 Limited and 1000 WRX Type R Version 6 Limited cars produced.
Japanese-spec Special Variants
22B STi (1998): In 1998, Subaru of Japan produced a widebody, 2-door, Impreza called the 22B STi. The 22B had the EJ22 engine as opposed to the regular EJ20 engine. This means the displacement was increased from 1994 cc to 2212cc. The block was a closed-deck borrowed from the Legacy's EJ22. The heads (valves, valvetrain and such) were lifted from the STi Version 4 engine. It produce 280 PS (206 kW) and 363 N·m (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 22B was used to commemorate the 3rd consecutive manufacturer's title for Subaru in the FIA World Rally Championship. This car was given a unique color of blue and had fender flared widebody taken from the Peter Stevens designed WRC car. It sported a Bilstein suspension, a triple-plate clutch, cryo-treated gears, a unique spoiler, a unique bumper and custom BBS gold wheels.
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 on the WRC car as 22B is a hexadecimal representation of the decimal number, 555.
It is interesting to note that the 22B STi that is suppose to be #13 was never given the plaque. Subaru of America imported #13 to be used as a press car.
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 (206 kW) (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.
