CP Pistons SC7421-4 Forged Pistons & Rings for 2004-2021 Subaru WRX STI EJ257

Vehicle Fitment

• 2004-2021 Subaru WRX STI (EJ257 2.5L Turbo, AWD)
• 2006-2014 Subaru WRX (EJ255 2.5L Turbo, AWD)

Fitment Notes

• Not compatible with 2002-2005 WRX models.
• Not compatible with 2008-2014 WRX STI models using the FA20DIT engine.

Features

• Forged 2618 aluminum construction for enhanced strength and durability.
• 100mm (3.937") bore size, suitable for +0.5mm overbore applications.
• Compression ratio of 8.2:1, ideal for high-boost and performance builds.
• Dish-top piston design to reduce compression for forced induction setups.
• Precision-machined to OEM tolerances for a perfect fit.
• Includes a complete set of 4 pistons, rings, and wrist pins.
• Compatible with both stock and aftermarket turbochargers.
• Designed to withstand extreme temperatures and pressures in high-performance environments.

Specifications

• Bore Size: 100mm (3.937 inches)
• Compression Ratio: 8.2:1
• Material: Forged 2618 Aluminum
• Includes: 4x Pistons, 4x Rings, 4x Wrist Pins
• Compression Height: 30.68mm
• Weight: Approximately 6 lbs
• Position: All cylinders (set of 4)

Included Components

• 1x Set of 4 Forged Pistons
• 1x Set of 4 Piston Rings
• 1x Set of 4 Wrist Pins
• 1x Set of 4 Circlips

Product Description

The CP Pistons SC7421-4 is a high-performance piston and ring kit designed for the 2004-2021 Subaru WRX STI and 2006-2014 WRX models equipped with the EJ257 and EJ255 2.5L turbocharged engines. These pistons are forged from 2618 aluminum, offering superior strength and durability to handle high-boost applications.

With a 100mm bore size and an 8.2:1 compression ratio, the SC7421-4 pistons are optimized for forced induction setups, providing the necessary strength to support significant power gains. The dish-top design reduces compression, making them ideal for high-boost and performance builds.

This kit includes a complete set of 4 pistons, rings, wrist pins, and circlips, ensuring you have all the components needed for a comprehensive engine rebuild. Whether you're upgrading your turbocharger or building a high-performance engine, the CP Pistons SC7421-4 offers the reliability and performance you need.