JE Pistons 310937 Forged Piston Kit for 2004-2021 Subaru WRX/STI EJ257

Vehicle Fitment

• 2004-2021 Subaru WRX (EJ255, EJ257)
• 2004-2021 Subaru STI (EJ257)

Features

• Forged 2618 T6 aluminum construction for high strength and durability
• Compression ratio of 9.5:1 for balanced performance and reliability
• 99.75 mm bore diameter for increased displacement and power
• Compression height of 1.209 in (30.7 mm) for precise fitment
• Negative 7.3 cc piston volume for optimized combustion efficiency
• Inverted dome/dish design to enhance flame travel and combustion
• Wrist pin diameter of 0.905 in (23 mm) compatible with stock rods
• Includes wrist pins, wire locks, and JE Pro Seal piston rings

Specifications

• Bore Diameter: 99.75 mm (3.927 in)
• Compression Height: 1.209 in (30.7 mm)
• Piston Volume: -7.3 cc
• Compression Ratio: 9.5:1
• Piston Material: 2618 T6 Forged Aluminum
• Wrist Pin Diameter: 0.905 in (23 mm)
• Wrist Pin Length: 2.250 in (57.15 mm)
• Piston Weight: Approximately 425 g each

Included Components

• 4x Forged Pistons
• 4x Wrist Pins (0.905 in diameter, 2.250 in length)
• 4x Piston Rings (1.2 mm top, 1.2 mm second, 2.5 mm oil ring)
• 4x Wire Lock Retainers

Product Description

The JE Pistons 310937 Forged Piston Kit is engineered for 2004-2021 Subaru EJ255 and EJ257 engines, including WRX and STI models. This kit offers a compression ratio of 9.5:1, making it ideal for enthusiasts seeking a balance between daily drivability and performance.

Constructed from 2618 T6 forged aluminum, these pistons are designed to withstand the high thermal and mechanical stresses associated with high-performance engines. The inverted dome/dish design enhances flame travel and combustion efficiency, while the negative 7.3 cc piston volume ensures optimized compression.

The kit includes all necessary components for installation, ensuring a comprehensive solution for engine rebuilding or performance upgrades. Please note that professional installation is recommended to ensure optimal performance and reliability.