Subaru EJ20 Engine 2.0L Turbo
The Subaru EJ20 is a 2.0-liter, turbocharged flat-4 (boxer) engine that defined the golden era of Japanese all-wheel-drive performance. Produced from 1989 to 2014, the EJ20 powered the legendary Impreza WRX STI through multiple generations (GC8, GDB, GRB). Featuring a unique semi-closed deck design, symmetrical turbocharger layout, and—on STI variants—factory forged internals, the EJ20 is renowned for its low center of gravity, rapid throttle response, and rally-bred durability.
Parameter | Value |
|---|---|
Engine Code | EJ20 (various: EJ20G, EJ20K, EJ205, EJ206, EJ207, EJ20X) |
Configuration | Flat-4 (Boxer / Horizontally Opposed) |
Displacement | 1,994 cc (2.0L) |
Bore x Stroke | 92.0 mm x 75.0 mm (Oversquare / Short-stroke design) |
Cylinder Block Material | Aluminum (with semi-closed deck on turbo variants) |
Cylinder Head Material | Aluminum |
Valvetrain | DOHC, 4 valves per cylinder (turbo) / SOHC (naturally aspirated) |
Compression Ratio | 8.0:1 – 9.5:1 (depending on variant) |
Fuel System | Multi-Point Electronic Fuel Injection (MPFI) |
Ignition System | Coil-on-plug (distributorless) with wasted spark |
Engine Weight (Dry) | 149 kg (328 lbs) |
Redline | 7,000 – 8,000 RPM (depending on variant) |
Variant | Application | Power | Torque | Key Features |
|---|---|---|---|---|
EJ207 (JDM STI) | Impreza WRX STI (GC8/GDB) 1994-2007 | 280-320 hp @ 6,400-7,200 rpm | 260-310 lb-ft @ 4,400 rpm | Forged pistons, semi-closed deck, 8,000 RPM redline |
EJ20G (Early WRX) | Impreza WRX (GC8) 1989-1996 | 240-250 hp @ 6,500 rpm | 220-240 lb-ft @ 5,000 rpm | Original EJ20 turbo, coil-on-plug, air-to-water intercooler (early) |
EJ20K (Version 4/5) | Impreza WRX STI (GC8) 1996-1998 | 280 hp @ 6,500 rpm | 260 lb-ft @ 4,000 rpm | Improved crankcase ventilation, larger turbo |
EJ205 (USDM WRX) | Impreza WRX (GD) 2001-2005 | 227 hp @ 6,000 rpm | 217 lb-ft @ 4,000 rpm | Open deck, less robust than EJ207 |
EJ206 (JDM Legacy) | Legacy B4 RSK (BE/BH) 1998-2002 | 280 hp @ 6,500 rpm | 260 lb-ft @ 5,000 rpm | Twin-turbo configuration (sequential) |
EJ207 (Version 7-9) | Impreza WRX STI (GDB) 2000-2007 | 280-320 hp @ 7,200-8,000 rpm | 260-310 lb-ft @ 4,400 rpm | Twin-scroll turbo, AVCS (intake cam timing) |
EJ20X | Legacy GT (BP/BL) 2003-2009 | 260 hp @ 6,000 rpm | 260 lb-ft @ 3,600 rpm | Detuned EJ207, open deck, common budget swap |
Boxer (Horizontally Opposed) Configuration: Pistons move horizontally (180° apart), creating a naturally low center of gravity for superior handling and balanced weight distribution.
Semi-Closed Deck Block (Turbo/STI variants): Cast-in reinforcement ribs around cylinder bores provide strength for high boost without the weight of a fully closed deck.
Symmetrical Turbo Layout: Turbocharger mounted low and centered for balanced exhaust routing and reduced turbo lag.
AVCS (Active Valve Control System): Subaru's variable valve timing system on intake cams (EJ207 Version 7+ and EJ205) improves low-end torque and throttle response.
Forged Internals (EJ207 STI): Factory forged pistons and shot-peened connecting rods for high-performance durability (8,000 RPM capable).
Twin-Scroll Turbo (EJ207 Version 7+): Quicker spool and broader torque curve compared to single-scroll designs.
DOHC 16-Valve Cylinder Head: High-flow cross-flow design with solid lifters on performance variants.
Top-Mount Intercooler (TMIC): Factory air-to-air intercooler positioned on top of the engine for short intake path.
Cast Iron Cylinder Liners: Press-fit liners provide wear resistance and allow for overboring.
Variant | Donor Vehicle | Key Notes |
|---|---|---|
EJ207 (JDM) | Impreza WRX STI (GC8/GDB/GRB) 1994-2007 | Most desirable. Semi-closed deck. Forged pistons. AVCS on V7+. |
EJ20G | Impreza WRX (GC8) 1989-1996 | Early version. Coil-on-plug. No AVCS. |
EJ20K | Impreza WRX STI (GC8) 1996-1998 | Version 4/5. Improved over EJ20G. |
EJ205 | Impreza WRX (GD) 2001-2005 (USDM) | Open deck. Less boost-friendly. Common and affordable. |
EJ206/EJ208 | Legacy B4 RSK (BE/BH) 1998-2002 | Twin-turbo (sequential). Complex vacuum system. |
EJ20X | Legacy GT (BP/BL) 2003-2009 | Open deck. Budget-friendly. Often used for hybrid builds. |
1x Subaru EJ20 Longblock (Cylinder head + engine block)
1x Intake Manifold (with or without TGV deletes – specify)
1x Turbocharger (VF series – VF22, VF28, VF30, VF34, VF37 depending on variant)
1x Exhaust Manifold (Equal or unequal length – "Subaru rumble" on unequal)
1x Top-Mount Intercooler (TMIC) – if included
1x Wiring Harness (if included – specify donor vehicle)
Injectors, alternator, starter, and ECU.