Manley Performance Pistons

Fits 2004+ Subaru WRX STi with EJ257 Engine

Part #: 621100C-4

Overview

The Manley Platinum Series piston set is a high-performance upgrade designed specifically for Subaru WRX STi models equipped with the EJ257 engine. Crafted from premium 2618 alloy forgings, these pistons are engineered to withstand the demands of spirited driving, tuning, and engine modifications. Ideal for professional engine builders, tuners, and enthusiasts seeking durability and consistent performance, these pistons help optimize engine response and reliability under high-stress conditions. Constructed with proven cam and barrel skirt profiles, the pistons promote efficient combustion and reduced friction, contributing to improved power output and longevity. The moly skirt coatings on select part numbers further enhance wear resistance, ensuring your engine maintains peak performance over time. Whether you're building a high-horsepower setup or upgrading for increased durability, these pistons provide a reliable foundation for your engine build.

Key Features

Designed with precision and quality, the Manley Platinum Series pistons feature:

• 2618 alloy forgings for strength and lightweight performance
• Proven cam and barrel skirt profiles for optimal combustion and reduced friction
• Tool steel wrist pins for durability and secure fitment
• Moly skirt coatings on select models for enhanced wear resistance
• 75mm bore diameter tailored for EJ257 engines
• 75mm stroke for a 99.5mm bore, supporting a 9.8:1 compression ratio
• Dish piston design to optimize combustion chamber clearance

Construction & Design

These pistons are meticulously engineered with high-grade 2618 alloy forgings, known for their excellent strength-to-weight ratio and thermal stability. The design incorporates proven skirt profiles and moly coatings to reduce friction and wear, ensuring long-lasting performance even under aggressive tuning conditions. The tool steel wrist pins are precision-machined for a secure fit, providing reliable operation during high RPM and boost scenarios.

Performance & Response

The lightweight forged construction and optimized profile help improve throttle response and engine efficiency. The dish design supports a high-performance combustion process, aiding in achieving consistent power delivery and fuel economy. These pistons are intended to support high-stress applications, making them suitable for builds that demand durability and reliable performance.

Installation & Fitment

Designed specifically for the EJ257 engine in Subaru WRX STi models from 2004 onward, these pistons are intended for high-performance engine rebuilds and upgrades. Proper installation requires standard engine assembly procedures and compatibility checks with your specific engine build.

What’s Included

This set includes the complete set of pistons with moly skirt coatings and tool steel wrist pins, ready for installation in your EJ257 engine. Hardware and additional components are not included and should be sourced according to your build requirements.

Ideal For

Enthusiasts and professional tuners building high-performance Subaru engines, seeking durable pistons capable of supporting increased power and boost levels while maintaining reliability and longevity.