Segment:
Performance compact sedan/hatchback, rally-bred sports car.
Target Audience:
Enthusiasts, rally fans, performance car owners seeking detailed repair and maintenance information.
Competitors:
Mitsubishi Lancer Evolution, Honda Civic Si, Volkswagen Golf GTI, Ford Focus RS (depending on region).
Selling Points Vehicle:
Legendary turbocharged boxer engine, Symmetrical All-Wheel Drive, aggressive styling, rally heritage, excellent handling dynamics.
Selling Points Manual:
Official Subaru documentation ensures accuracy and completeness, essential for maintaining the unique performance characteristics of the WRX STI.
Years Covered:
2001, 2002, 2004, 2005, 2006, 2007
Regions Covered:
Likely Global (varies by specific manual edition, assume US/European focus for this context)
Approximate Pages:
Varies significantly by manufacturer edition, typically 1000-3000+ pages for comprehensive workshop manuals.
Type:
Official Workshop Service and Repair Manual
Language:
English (standard for primary documentation)
Format:
Likely Digital (PDF), potentially available in print.
Engine:
Engine mechanical, lubrication system, cooling system, fuel injection, ignition system, emission control, engine management, turbocharger system.
Transmission:
Manual transmission (TY756), clutch system, driveline, all-wheel drive system (Symmetrical AWD).
Brakes:
Brake system components (front/rear discs), ABS, hydraulic system, parking brake.
Suspension:
Front and rear suspension, shock absorbers, springs, bushings, alignment specifications.
Steering:
Steering system components, power steering, steering column.
Electrical:
Wiring diagrams, lighting system, instrument panel, audio system, power accessories, charging system, starting system, ECUs.
Body:
Body exterior panels, interior trim, doors, windows, roof, underbody, chassis specifications, welding points.
Climate Control:
HVAC system, air conditioning, heating, ventilation.
Maintenance:
Scheduled maintenance intervals, fluid changes (oil, coolant, brake, transmission), filter replacements, spark plug service.
Diagnostics:
Troubleshooting guides, symptom-based diagnostics, DTC (Diagnostic Trouble Code) interpretation, testing procedures for components.
Repair:
Step-by-step repair procedures for all major systems, including engine overhaul, transmission rebuild, brake component replacement, suspension work, electrical component repair.
Installation:
Procedures for replacing various parts and components, including engine mounts, exhaust systems, body panels, electrical modules.
Specifications:
Torque specifications for fasteners, clearances, fluid capacities, electrical system parameters, diagnostic readings.
Depth:
Comprehensive: Covers everything from basic maintenance to full engine and transmission rebuilds. Includes detailed schematics, diagnostic procedures, and component-level repair instructions.
Digital Format:
PDF (Portable Document Format) - typically optimized for searchability and printing.
Quality:
High-resolution scans or original manufacturer digital files, ensuring clarity of diagrams and text.
Binding:
N/A for digital, if printed would typically be spiral-bound or perfect-bound for durability in a workshop environment.
Paper Type:
N/A for digital, if printed would be durable paper stock suitable for workshop use.
Engine Code:
EJ257 (for most STI models of this generation)
Engine Type:
2.5L (2457cc) DOHC Turbocharged Boxer-4
Bore X Stroke:
99.5 mm x 79.0 mm
Horsepower Est:
Approx. 300-320 hp (varies by market and specific year/tune)
Torque Est:
Approx. 300-330 lb-ft (varies by market and specific year/tune)
Fuel Delivery:
Multi-point fuel injection (MPI) with sequential fuel injection and ECU control.
Fuel Type:
Premium Unleaded Gasoline (91 octane or higher recommended/required)
ECU:
Subaru Engine Control Unit (ECU) with specific STI tuning.
Turbo Model:
IHI VF37 or similar (variable wastegate twin-scroll turbocharger)
Type:
6-speed manual transmission
Gear Ratios Typical:
Refer to manual for specific ratios; generally close-ratio for performance driving.
Type:
None (STI models exclusively manual transmission during this generation)
Drivetrain:
Symmetrical All-Wheel Drive (AWD) with Driver Controlled Center Differential (DCCD).
Clutch:
Hydraulically operated multi-plate clutch.
Transmission Fluid:
Refer to manual for specific Subaru specifications (e.g., GL-5 gear oil, often 75W-90).
NHTSA Ratings Typical:
Varies by year and specific test, but generally good for its era, though specific STI crash data might be limited separately.
AWD:
Symmetrical All-Wheel Drive with Driver Controlled Center Differential (DCCD) enhances traction and stability.
ABS:
Anti-lock Braking System (ABS).
Traction Control:
Active Differential Control (DCCD) and AWD system contribute to traction management.
Airbags:
Front airbags, side airbags (availability may vary by year/trim).
Seatbelts:
3-point seatbelts with pre-tensioners and load limiters.
Body Structure:
Reinforced chassis and crumple zones.
Head Unit:
Typically a factory-branded AM/FM/CD player. Upgrades common.
Audio System:
Standard speaker setup, some trims may offer premium audio options.
Traction Control:
AWD system and DCCD are primary traction aids.
Cruise Control:
Standard electronic cruise control.
Aux Input:
Rare or non-existent on base units; aftermarket solutions common.
Dccd:
Driver Controlled Center Differential allows manual adjustment of the front-to-rear torque split for varying road conditions.
Intercooler:
Top-mounted intercooler (TMIC) is standard; some models/years might have water spray.
Oil Change:
Typically every 3,000-5,000 miles or 6 months (synthetic oil recommended for performance use).
Air Filter Replacement:
Refer to manual, typically every 15,000-30,000 miles.
Spark Plug Replacement:
Refer to manual, typically 60,000 miles for iridium plugs.
Timing Belt:
This generation typically uses a timing *belt*. Refer to manual for interval (often 60,000-100,000 miles or 7-10 years).
Engine Oil:
Refer to manual for specific viscosity and API rating (e.g., 5W-30 or 10W-30 synthetic recommended).
Coolant:
Subaru Super Coolant (or equivalent HOAT coolant, blue color).
Brake Fluid:
DOT 3 or DOT 4 brake fluid (refer to manual for exact spec).
Engine Reliability:
Head gasket failures (though less common on EJ257 compared to earlier EJ25s), ringland failures under high boost/poor tuning, oil consumption.
Turbocharger:
Turbo seal failure leading to oil burning, wastegate issues.
Suspension:
Worn bushings, premature strut failure, especially under spirited driving.
Drivetrain:
Clutch wear, differential issues if abused.
Tuning Impact:
Aftermarket tuning can significantly impact reliability if not done correctly; always use reputable tuners.
Rally Roots:
Subaru's extensive success in the World Rally Championship (WRC) is directly tied to the Impreza platform, especially the WRX STI variants.
Generation Context:
The GDB generation (2000-2007) saw significant evolution, with the STI model gaining more power, advanced AWD systems, and a distinct identity from the standard Impreza.
Performance Upgrades:
Introduction of DCCD, larger intercoolers, stronger transmissions, and more potent engine tunes distinguished the STI from the WRX.
Manufacturing Locations:
Primarily Japan (Gunma Plant).
Key Model Years Covered:
2001-2007, capturing the latter half of the GDB generation, including key updates.
Motorsport Legacy:
Multiple WRC manufacturer and driver championships, forming the basis of the Impreza's performance reputation.
Car And Driver Denom:
Often lauded by automotive journalists for its performance, handling, and value in the sports compact segment.
Iconic Status:
The WRX STI of this era is considered a modern automotive icon, highly sought after by enthusiasts.
