Manley 04+ Subaru WRX STi EJ257 99.5mm Bore STD 8.5CR -17cc Dish Piston Set w/Rings

When you're rebuilding the heart of your 04+ Subaru WRX STi with the EJ257 engine, starting with a solid set of pistons is key. These Manley Performance pistons are forged from a domestic 2618 alloy, a material chosen for its strength and ability to handle the demands of a performance engine build. They're designed with specific cam and barrel skirt profiles, which help them generate power efficiently while also being kinder to your cylinder walls during operation.

Manley pays close attention to the details that make a difference in engine performance. The ring lands and grooves are machined to exacting standards, which is crucial for a good seal and maximizing the power your engine can produce. They also use a unique fixturing process that allows them to machine the skirt and ring grooves in one operation. This ensures the ring grooves are perfectly square to the skirt, contributing to better ring seal and overall engine health. Each set comes with premium chrome moly wrist pins, and for those looking for even more durability, Manley offers upgrades to 9310 and Turbo Tuff/DLC alloys on select part numbers.

This set is specifically for the EJ257 engine, featuring a 99.5mm bore and a dish volume of -17cc, resulting in a compression ratio of 8.5:1. Keep in mind that these pistons are not CARB approved and cannot be shipped to California. If you're building a high-performance engine, these Manley pistons are a well-built choice that professional engine builders trust.