JE Pistons 314438 Forged Pistons for 2002-2005 Subaru Impreza WRX EJ205 92.5mm

Vehicle Fitment

• 2002-2005 Subaru Impreza WRX (GD/GG Chassis, 2.0T EJ205, AWD)
• 1999-2005 Subaru Impreza WRX (JDM GC/GD Chassis, 2.0T EJ205, AWD)
• 1999-2005 Subaru Impreza WRX STI (JDM GC/GD Chassis, 2.0T EJ207, AWD)

Fitment Notes

• This is an oversize +0.50mm (92.5mm) bore piston set. Engine block must be bored and confirmed at 92.5mm before installation.
• Fits the Phase II EJ205 and EJ207 engines (1999 and newer) with the 92mm stock bore block. Does not fit Phase I (pre-1999) EJ20G or EJ20K engines.
• USDM 2002-2005 Impreza WRX uses the non-AVCS EJ205. JDM 1999-2005 WRX and STI versions use AVCS-equipped EJ205/EJ207 - all share the same bore and are compatible with this piston set.
• Does not fit the EJ257 (2.5L) used in the USDM 2004+ Impreza WRX STI - that engine uses a 99.5mm bore.
• Does not fit the EJ255 (2.5L) used in the USDM 2006-2014 WRX, Forester XT, or Legacy GT.
• Asymmetrical FSR piston design - left (front) and right (rear) pistons are handed. Confirm correct orientation during assembly.

Features

• Forged from 2618 T6 high-tensile aluminum alloy for maximum durability under high-boost turbocharged and nitrous applications.
• Asymmetrical FSR (Forged Side Relief) construction reduces piston mass and skirt-to-wall contact area, lowering friction and improving ring seal.
• Dish crown design (-11.7cc) with smooth flowing radii engineered for the EJ205/EJ207 combustion chamber geometry and flame travel pattern.
• Dome/dish surface requires no deburring or preparation - ready to install directly from the box.
• Precision CNC-machined ring grooves maintain tight tolerances for consistent ring seal under sustained boost and high RPM.
• Compatible with forced induction (turbo) and nitrous oxide applications at professional competition power levels.
• Engineered and forged 100% in the USA by JE Pistons - the most trusted name in sport compact forged racing pistons.
• All four pistons balanced within tolerance for smooth, vibration-free boxer engine operation.
• Rings, wrist pins (Tru-Arc locking), and pin locks included - complete hardware package for assembly.
• Designed for extreme applications from street performance to full competition drag, rally, and time attack builds.

Specifications

• Part Number: 314438
• Bore Size: 92.5mm (3.642 in) - Oversize +0.50mm
• Stroke: 75mm (2.953 in)
• Rod Length: 130.50mm (5.138 in)
• Compression Distance (CH): 32.7mm (1.287 in)
• Dome/Dish Volume: -11.7cc (Dish)
• Compression Ratio: 8.5:1
• Piston Weight: 359-367 grams each (varies by bore size)
• Material: 2618 T6 Forged Aluminum Alloy
• Skirt Style: Asymmetrical FSR (Forged Side Relief)
• Ring Widths: 1.0 x 1.2 x 2.8mm
• Wrist Pin Diameter: 23mm (0.905 in)
• Wrist Pin Length: 57.15mm (2.250 in)
• Wrist Pin Type: Straight-wall carbon steel
• Pin Lock Type: Tru-Arc
• Application: Subaru EJ205 / EJ207 2.0L Turbo Boxer
• Quantity in Set: 4 pistons

Included Components

• 4x Forged 2618 aluminum asymmetrical FSR pistons (92.5mm bore)
• 4x Carbon steel straight-wall wrist pins (23mm)
• 4x Sets of piston rings (1.0 x 1.2 x 2.8mm)
• 4x Tru-Arc pin lock sets

Product Description

The JE Pistons 314438 is a complete forged piston set designed specifically for the Subaru EJ205 and EJ207 2.0L turbocharged boxer engine, covering the USDM 2002-2005 Impreza WRX and the JDM 1999-2005 WRX and WRX STI. Built from 2618 T6 forged aluminum alloy and featuring JE's Asymmetrical FSR (Forged Side Relief) architecture, these pistons are engineered to withstand the extreme thermal and mechanical loads produced by high-boost performance builds. The deep dish crown (-11.7cc) is precisely shaped for the EJ-series combustion chamber, delivering an 8.5:1 compression ratio - a popular target for builders running larger turbochargers at elevated boost pressures, where lower static compression helps manage cylinder pressure and detonation risk.

At 92.5mm bore (+0.50mm oversize), this set is intended for engines that have been bored oversize as part of a performance rebuild or to clean up worn cylinder walls. The asymmetrical FSR skirt design reduces reciprocating friction and piston mass compared to conventional forged designs, while the precision CNC-machined ring grooves ensure long-term ring seal integrity at high RPM and boost levels. Each piston ships with matching rings, 23mm straight-wall carbon steel wrist pins, and Tru-Arc locking clips - providing a complete, ready-to-assemble kit. Note that the EJ205/EJ207 uses a handed (asymmetrical) piston design, so correct left/right orientation must be confirmed during assembly; pistons should not be swapped between front and rear cylinder pairs.

The JE 314438 is the benchmark piston choice for builders constructing high-output EJ205 or EJ207 short blocks for time attack, drag racing, rally, or aggressive street use. Whether the goal is a reliable 400whp daily driver or a purpose-built competition engine, these pistons provide the proven forged foundation required for serious power builds on the EJ platform. Builders should confirm the engine uses the Phase II EJ205 or EJ207 block (1999 and newer) and verify bore size prior to ordering, as this set is not compatible with the 2.5L EJ255 or EJ257 engines used in later USDM WRX and STI applications.