CP Pistons Forged Pistons Subaru EJ20 / EJ205

CP Pistons – Subaru EJ20 WRX Forged Piston Set

CP Pistons' forged piston range for Subaru EJ20 is engineered for turbocharged high-performance builds demanding superior strength and reliability. Designed for a 75 mm stroke and 130.5 mm rod length, these pistons are perfect for street and track setups running elevated boost, RPM, or aggressive tuning.

Each piston is CNC-machined from high-strength forged aluminium, featuring an optimised skirt profile and valve reliefs for excellent sealing, efficiency, and durability. Offered in multiple bore sizes with consistent compression ratio (8.5:1), this set caters to rebuilds and oversized applications.

Key Features

• Engineered for Subaru EJ20 WRX and EJ205 engines
• Designed for 75 mm stroke and 130.5 mm rod length
• Forged from high-strength aluminium for superior performance
• Compression ratio of 8.5:1 – ideal for forced induction
• Balanced weight and optimised dome for power and reliability

Available Variants

Technical Overview

• Stroke: 75 mm
• Rod Length: 130.5 mm
• Compression Height: 1.285 in
• Wrist Pin: 23 mm (0.9055 in), included – 905-2500-18CP1S
• Ring Pack: 1.0 mm / 1.2 mm / 2.8 mm – 905x055 SUB
• Locks: Spiral locks – part numbers vary per piston (e.g. R51313-3622-0)
• Fitment: Subaru EJ20 WRX / EJ205