Manley Performance Pistons

Fits Subaru WRX STi 2004+ with EJ257 Engine

Part #: 621005C-1

Overview

The Manley Platinum Series pistons are high-performance engine components designed for serious Subaru WRX STi enthusiasts and professional tuners. Crafted from 2618 alloy forgings, these pistons deliver exceptional strength, durability, and consistent performance under demanding conditions. Engineered specifically for the EJ257 engine, they are ideal for builds that require reliable power support and longevity. Whether you're upgrading for increased horsepower or building a race-ready motor, these pistons help optimize your engine's response and efficiency. Designed with proven cam and barrel skirt profiles, the Platinum Series pistons ensure precise fitment and smooth operation. The moly skirt coatings on select part numbers reduce friction and wear, extending the lifespan of your engine components. Equipped with tool steel wrist pins, these pistons are built to withstand high loads and thermal stresses, making them suitable for both daily driving and high-performance applications.

Key Features

Our signature pistons combine advanced materials and thoughtful design to support your engine build:

• Made from 2618 alloy forging for superior strength and thermal stability
• Designed with proven cam and barrel skirt profiles for optimal fit and performance
• Tool steel wrist pins for enhanced durability and load capacity
• Moly skirt coatings on select models to reduce friction and wear
• 75mm bore size with a +0.5mm oversize for custom engine builds
• Dished design with an 8.5:1 compression ratio to support high-performance tuning
• Engineered for EJ257 engines in Subaru WRX STi models 2004 and newer

Construction & Design

These pistons feature precision-machined forging from high-quality 2618 alloy, known for its excellent strength-to-weight ratio and thermal properties. The moly skirt coatings provide a low-friction surface, helping to reduce piston slap and improve overall engine efficiency. The design incorporates a dish top to support specific compression ratios and combustion chamber requirements, ensuring reliable performance across a range of tuning applications.

Driving Feel & Feedback

Built to support high-performance engines, these pistons help deliver a responsive throttle feel and consistent power delivery. Their robust construction ensures durability under aggressive driving conditions, providing confidence and reliability during spirited driving or racing.

Installation & Fitment

Designed specifically for the EJ257 engine in Subaru WRX STi models from 2004 onward, these pistons are intended for professional installation and engine rebuilds. Proper machining and assembly are recommended to ensure optimal performance and longevity.

What’s Included

This package includes a single piston designed for high-performance engine builds, with the necessary wrist pin and associated hardware included for installation.