🏷️ Basic Information Identification Make: Subaru Model: Impreza WRX STI Model Code: GDB (Global Design Box - refers to the chassis generation) Year: 2006-2007 Codes Chassis Code: GDB-F (for 2006-2007 models, representing the final iteration of this generation) Engine Code: EJ257 (for most markets, especially North America) 👋 Introduction Market Position Positioning: The Subaru Impreza WRX STI of this generation (GD chassis, specifically the 'F' iteration) represented the pinnacle of Subaru's rally-bred performance in a compact sedan package, offering a potent blend of all-wheel-drive grip, turbocharged power, and driver engagement. Competitive Analysis Competitors: Competed directly with performance variants of cars like the Mitsubishi Lancer Evolution, Ford Focus RS, Honda Civic Type R (in spirit, though less AWD), and Volkswagen Golf GTI/R32. Key Features Performance Focus: Emphasized tarmac and gravel rally performance, symmetrical all-wheel-drive, turbocharged boxer engine, advanced differential systems. Driver Engagement: Known for sharp steering, communicative chassis, and a visceral driving experience. 📋 Manual Details Coverage Areas Geographic Coverage: Primarily North America and global markets for the GDB chassis WRX STI. Trim Level Coverage: WRX STI models, including specific variations that may have existed within these years. Page Count Estimated Pages: 1500-2500+ (typical for comprehensive factory service manuals of this era and complexity) Manual Type Type: Factory Service Manual (FSM) / Workshop Manual Language Language: English Format Format: PDF (Digital Download) 📖 Manual Coverage Systems Covered Engine: Detailed diagnostics, repair, overhaul, timing belt/chain, lubrication system, cooling system, fuel injection, turbocharger system, emissions control. Transmission: Manual transmission (TY856WR1CA, 6-speed), clutch system, driveline, differential (front and rear DCCD system). Brakes: Front and rear disc brakes, ABS (Anti-lock Braking System), brake fluid, hydraulic system, parking brake. Suspension: Front and rear suspension components, struts, springs, control arms, bushings, sway bars, DCCD (Driver Controlled Center Differential) system integration. Steering: Power steering system, steering rack, column, alignment specifications. Electrical System: Battery, charging system, starting system, ignition system, lighting, instruments, body electronics, CAN bus communication (limited), diagnostic trouble codes (DTCs). HVAC: Heating, ventilation, and air conditioning system diagnosis and repair. Body And Chassis: Body panel removal and installation, interior trim, chassis structural information, welding points (if applicable). Procedures Included Maintenance: Oil changes, filter replacements, spark plug replacement, fluid checks and changes, brake pad replacement, belt inspection. Repair: Engine rebuilds, transmission overhauls, suspension component replacement, brake system repairs, electrical component diagnosis and replacement. Troubleshooting: Systematic diagnostic procedures for various symptoms, DTC interpretation and resolution. Diagnostics: On-Board Diagnostics (OBD-II) procedures, specific Subaru diagnostic tools and procedures, sensor testing, actuator testing. Specifications: Torque specifications for all fasteners, clearances, pressures, voltages, resistances. Wiring Diagrams: Comprehensive electrical wiring diagrams for all vehicle systems. Technical Depth Depth: Complete workshop level. Covers everything from basic maintenance to full engine and transmission rebuilds, detailed electrical troubleshooting, and body repair. 📊 Manual Specifications File Format File Type: PDF Searchable Text: Yes (typically, depending on original scanning quality) Print Quality Printability: Printable (intended for user printing) Binding Type Binding Recommendation: Spiral or comb binding recommended for workshop use. Paper Type Paper Recommendation: Heavyweight, durable paper suitable for shop environments. ⚙️ Engine Specifications Primary Engine Engine Type: Horizontally-opposed (Boxer) turbocharged 4-cylinder Engine Code: EJ257 Displacement: 2.5 Liters (2457 cc) Bore X Stroke: 99.5 mm x 79.0 mm Compression Ratio: 8.2:1 Performance Horsepower Usdm: 300 hp @ 6000 rpm (approximate, varies slightly by market) Torque Usdm: 300 lb-ft @ 4000 rpm (approximate, varies slightly by market) Fuel System Fuel Delivery: Sequential multi-point fuel injection (MPI), Electronic Throttle Control (ETC) Fuel Type: Premium Unleaded Gasoline (91 octane or higher recommended) Engine Management ECU Type: Subaru Select Monitor (SSM) compatible ECU Turbocharger Turbo Model: IHI VF39 (or VF37 depending on market/specific variant) Intercooler: Top-mount air-to-air intercooler Engine Code Engine Code Specifics: EJ257 typically features larger ports and higher flow injectors compared to standard WRX EJ255. 🔧 Transmission Standard Transmission Type: 6-speed Manual Transmission Model: TY856WR1CA (or similar 6-speed variant) Optional Transmission Type: N/A (STI models were exclusively manual) Features Dccd: Driver Controlled Center Differential (manual operation via console dial, auto mode available) Differential Types: Front: Helical LSD; Rear: Viscous LSD (with DCCD control for center). Fluid Specifications Manual Transmission Fluid: Subaru Genuine Gear Oil API GL-5 75W-90 (or equivalent high-quality synthetic 75W-90) 📐 Dimensions Exterior Wheelbase: 2515 mm (99.0 inches) Length: 4405 mm (173.4 inches) Width: 1770 mm (69.7 inches) Height: 1440 mm (56.7 inches) Weights Curb Weight: 1505 kg (3318 lbs) (approximate) Gross Vehicle Weight Rating: Not explicitly stated, but generally around 1900-2000 kg. Cargo Trunk Capacity: 0.33 m³ (11.7 cu ft) (approximate, varies slightly) Wheels And Tires Wheel Size: 17x8.0 inches (standard), 18x8.0 inches (optional/later models) Bolt Pattern: 5x100 mm Tire Size Standard: 225/45R17 Tire Size Optional: 225/40R18 or 235/40R18 🛡️ Safety Features Ratings NHTSA Front Crash Rating: 5-star (for driver and passenger, typical for this chassis generation) IIHS Side Impact Rating: Good (typically for this chassis generation) Active...