Manley 04+ Subaru WRX STi (EJ257) 75mm DE-STROKED 99.75mm +.25mm Bore 9.8:1 Dish Piston Set w/ Rings

This Manley piston set includes four forged pistons, a full set of piston rings, and premium chrome moly wrist pins. These are designed for the 2004-2012 Subaru Impreza WRX STi with the EJ257 engine, featuring a de-stroked 75mm crankshaft, a bore of 99.75mm (which is 0.25mm overstock), and a dish top that results in a 9.8:1 compression ratio. This setup is popular for builders looking to refresh or upgrade their EJ257 engine internals.

Manley uses domestic 2618 alloy forgings for these pistons, which are known for their strength and ability to handle higher performance demands compared to cast aluminum. The pistons feature proven cam and barrel skirt profiles, designed to reduce friction and wear on the cylinder walls while still generating substantial power. The ring lands and grooves are machined to strict standards, which helps ensure a better seal between the piston and cylinder wall, leading to improved power output and efficiency. Manley's unique manufacturing process allows them to machine the skirt and ring grooves in a single operation, ensuring the squareness of the ring grooves relative to the piston skirt for optimal performance.

This piston set is a solid option for engine rebuilds where enhanced durability and performance are key. It's important to note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for proper fitment and assembly procedures.