Subaru's EJ257 engine is the heart and soul of the iconic WRX STI, delivering an exhilarating performance that puts driving enthusiasts on the edge of their seats. This turbocharged 2.5-liter boxer engine is well known to pack a full wallop in terms of power and deliver exceptional tuning potential.
The EJ257 came from the Subaru rally heritage, combining high-strength internals with advanced engineering to provide substantial boost pressures. A semi-closed deck design (on 2008+ STI variants) and forged connecting rods provide a great base for both stock and modified applications.
Known for being responsive and creating that unique boxer rumble, the Subaru EJ257 engine for sale here really lets you know it's time to get that blood pumping. Whether looking for a replacement motor or piecing together a high-performance build, this powerplant melds the perfect mixture of reliability with untapped potential to send your Subaru performance into the stratosphere.
The Subaru EJ257 is a turbocharged 2.5-liter flat-four, featuring a horizontally opposed "boxer" design. It features an aluminum block and heads with reinforced internals to handle high boost pressures. Additionally, it features a Dual Active Valve Control System, which allows for optimized valve timing on both the intake and exhaust banks for more power availability across the rev range.
Key features include a high-flow IHI VF48 turbocharger, top-mount intercooler, and multi-port fuel injection with larger STI-spec injectors. In stock trim, this Subaru EJ257 engine for sale here typically produces 300-305 horsepower and 290 lb-ft of torque.
This listing is for the stock factory Subaru EJ257 STI engine , not the Cosworth EJ257 performance build. The difference is significant:
| Feature | Stock Factory EJ257 (This Listing) | Cosworth EJ257 (Separate Listing) |
|---|---|---|
| HP | 300-305 HP | 330-350 HP |
| Torque | 290 lb-ft | 330-340 lb-ft |
| Block Design | Open-deck (2004-2007) / Semi-closed deck (2008+) | Full closed-deck |
| Crankshaft | Cast | Forged |
| Connecting Rods | Forged H-beam (factory STI) | Forged H-beam (Cosworth) |
| Pistons | Cast | Forged (Cosworth) |
| Head Gaskets | Stock | Multi-layer steel (Cosworth) |
| Power Ceiling | ~400-450 HP safe | 500-700+ HP |
| Price (Used) | $4,500-8,500 | $4,999-9,500 |
| Source | Factory Subaru WRX STI donor | Cosworth-built performance unit |
The stock factory EJ257 is excellent for replacement applications and builds up to about 450 HP. For serious 500+ HP builds, the Cosworth EJ257 is the recommended starting point.
The EJ257 takes the EJ255 mainstream turbo and applies STI-spec upgrades:
| Vehicle | Years | Chassis Code | Notes |
|---|---|---|---|
| Subaru WRX STI (1st gen US) | 2004-2007 | GD | Original US WRX STI, open-deck block, 300 HP |
| Subaru WRX STI (2nd gen US, hatch) | 2008-2014 | GR | Hatchback STI, semi-closed deck introduced, 305 HP |
| Subaru WRX STI (2nd gen US, sedan) | 2011-2014 | GV | Sedan STI variant, same EJ257 platform, 305 HP |
| Subaru WRX STI (3rd gen US) | 2015-2021 | VA | Final EJ257 STI generation, refined semi-closed deck, 305 HP |
| Subaru Forester STI | JDM only | SG / SH | JDM-only application of EJ257 |
Same documented issue as EJ255 , cast pistons can develop ringland failures under high boost or detonation:
Despite the forged rods, rod bearing wear is documented at very high mileage (150,000+ miles). Less common than EJ255 cast rod failures, but service item worth verifying.
At 80,000-120,000 miles, AVCS solenoids on intake or exhaust can develop failures producing check engine codes and reduced upper-RPM power. Both intake and exhaust solenoids documented. Service: replace AVCS solenoid ($200-300 part each).
Common cause of turbo oil starvation on EJ-series turbos. Should be inspected at any service interval. Failure causes catastrophic turbocharger failure.
Here at Vaz Auto Solutions, you'll find this Subaru EJ257 engine for sale at the most reasonable price possible, with variant verified (stock factory EJ257 STI, not Cosworth build), donor vehicle confirmed (WRX STI chassis generation identified), all 4 cylinders compression tested, turbocharger condition verified, AVCS function tested on both intake AND exhaust (Dual AVCS), forged connecting rods verified, block deck type identified, and complete inspection.
| Vehicle | Compatibility |
|---|---|
| Subaru WRX STI (1st gen US, GD chassis) | 2004-2007 with EJ257 turbo (open-deck block) |
| Subaru WRX STI (2nd gen US, GR hatch) | 2008-2014 with EJ257 turbo (semi-closed deck) |
| Subaru WRX STI (2nd gen US, GV sedan) | 2011-2014 with EJ257 turbo (semi-closed deck) |
| Subaru WRX STI (3rd gen US, VA chassis) | 2015-2021 with EJ257 turbo (semi-closed deck, final generation) |
| Performance Engine Swaps | Forester XT, Legacy GT, Impreza performance builds (with appropriate ECU, fuel system, and supporting modifications) |
| Engine Type | Turbocharged | DOHC | Flat-4 (horizontally opposed boxer) |
|---|---|
| Engine Variant | Stock factory EJ257 STI (NOT Cosworth performance build) |
| Engine Family | Subaru EJ-series | turbocharged 2.5L STI flagship |
| Manufacturer | Subaru Corporation |
| Configuration | Flat-4 (horizontally opposed boxer |
| Displacement | 2.5L (2 | 457 cc) |
| Bore X Stroke | 99.5 mm x 79.0 mm |
| Hp | 300 HP (2004-2007 GD) / 305 HP (2008-2021 GR/GV/VA) |
| Hp Range Live Page | 224-305 HP (covers some lower-tune applications) |
| Torque | 000 rpm | 290 lb-ft at 4 |
| Compression | 8.2:1 |
| Aspiration | Turbocharged with intercooler |
| Turbocharger | IHI VF48 typical |
| Intercooler | Top-mount (TMIC) |
| Fuel System | Sequential multi-port injection with larger STI injectors |
| Fuel Type | 93 recommended) | Premium 91 octane minimum |
| Valvetrain | 16 valves | DOHC per bank | Dual AVCS (intake + exhaust) |
| Block Material Early | Open-deck aluminum (2004-2007 GD) |
| Block Material Later | Semi-closed deck aluminum (2008-2021 GR/GV/VA) |
Contact (240) 301-0095 within 15 days.
