JE Pistons 361331 Ultra Series Forged Piston Set for Subaru EJ257 99.75mm Bore

Vehicle Fitment

• 2004-2017 Subaru WRX STI (EJ257, AWD)
• 2005-2006 Subaru Legacy GT (EJ255, AWD)
• 2005-2006 Subaru Outback XT (EJ255, AWD)

Features

• Forged 2618 T6 high-tensile aluminum construction for enhanced strength
• Inverted dome/dish design for optimized combustion efficiency
• Precision CNC machining for consistent quality and performance
• Compatible with high-boost applications and nitrous setups
• Designed for both press-fit and floating wrist pin configurations
• Includes wrist pins, locks, and JE Pro Seal premium piston rings
• Made 100% in the USA
• Ideal for both street and track applications

Specifications

• Bore Diameter: 99.75 mm (3.927 inches)
• Compression Height: 1.209 inches (30.70 mm)
• Piston Volume: -7.30 cc
• Compression Ratio: Approximately 9.5:1 (calculated with 0.0" deck clearance & 0.040" gasket)
• Piston Material: Forged 2618 aluminum
• Piston Head Type: Inverted Dome/Dish
• Wrist Pin Diameter: 0.905 inches (23.00 mm)
• Wrist Pin Length: 2.250 inches (57.15 mm)
• Average Piston Weight: 426 grams
• Ring Set Included: Yes (1.2 x 1.2 x 2.5 mm)
• Pin Locks Included: Yes

Included Components

• 1x JE Ultra Series Piston Set (4 pistons)
• 1x Ring Set (4 sets)
• 1x Wrist Pin Set (4 pins)
• 1x Pin Lock Set (4 locks)

Product Description

The JE Pistons 361331 Ultra Series Piston Set is engineered for high-performance applications in Subaru's EJ257 and EJ255 engines, found in the 2004-2017 WRX STI, 2005-2006 Legacy GT, and 2005-2006 Outback XT models. These pistons are ideal for enthusiasts seeking to enhance their engine's performance, especially in applications involving forced induction or high-revving setups.

Constructed from forged 2618 T6 aluminum, these pistons offer superior strength and durability, making them suitable for high-boost builds. The inverted dome/dish design optimizes combustion efficiency, while the skirt coating minimizes wear on piston skirts and cylinder walls.

The kit includes a ring set, wrist pins, and pin locks, ensuring all necessary components are provided for installation. With a compression ratio of approximately 9.5:1, these pistons are compatible with both naturally aspirated and forced induction setups, including turbocharged and supercharged applications.