Category Archives: USDM

2nd Generation Subaru Impreza WRX STi United Kingdom varients

Impreza WR1
Impreza WR1

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 316 bhp (236 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.

2004 – 2007 USDM STi breakdown

2004 – 2007 USDM STi breakdown:

A Stock 2005 USDM 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 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 STi’s 15.2:1 instead of the Spec C’s 13:1

2004 – 2007 USDM STi breakdown:

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.

2004 – 2007 USDM STi breakdown:

Rev. F (2006)
The US-spec STIs receive the same face lift 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 2006 STI weighs approximately 3,350 lb (1,520 kg).

The second generation Subaru Impreza WRX STi

Subaru Impreza WRX STi winter driving.

Second generation (2001 – 2007)
Second generation (GDB-F)
Production 2001-2007
Body style(s) 4-door sedan
4-door station wagon
Engine(s) 2.0L H4
2.5L H4
Transmission(s) 6-speed manual
5-speed semi-automatic
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)
Curb weight 3,296 lb (1,495 kg)
Related Subaru Impreza
Subaru Forester
Subaru Impreza WRX
Saab 9-2X
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 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 turbochargers are IHI models. 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 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 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. Each relates to a creature that has similar looking eyes: 2002-2003 are ‘bug eyes’ / 2004-2005 are ‘Tear Drop’ or ‘blob eyes’ / 2006-2007 are ‘hawk eyes’.

5spd Subaru WRX five speed manual tips and tricks

5spd Subaru WRX five speed manual tips and tricks:

So you’ve got this noise coming from your 5spd transmission. It is starting to whine when you’re on/off the throttle. The sound seems to come right from below like around the shifter area. You may be a victim of the infamous falling apart center differential!

Don’t be too worried, transmissions are a dime a dozen! You still have the option to go 6spd or another 5spd transmission with different gear ratios if you choose.

5Spd: The damage. Most times the rear cover will back out minor like this photo. Other times it will completely come off. You can see the circlip survived this incident on this WRX