Manley 04+ Subaru WRX STi (EJ257) STD Stroke 99.75mm +.25mm Bore 8.5:1 Dish Piston Set with Rings

If you're rebuilding the engine in your 2004-2012 Subaru Impreza WRX or STi, these forged pistons from Manley Performance are a solid choice. They're designed for the EJ257 engine and come in a 99.75mm bore size, which is +.25mm over standard, with a dish volume that results in an 8.5:1 compression ratio. This setup is ideal for building a robust engine that can handle increased boost or higher performance demands.

Manley uses domestic 2618 alloy forgings for these pistons, which are known for their strength and ability to perform under stress. They feature proven cam and barrel skirt profiles that help manage piston rock, reducing wear on your cylinder walls while still allowing the piston to generate substantial power. The ring lands and grooves are machined to very strict standards, ensuring a good seal with the included rings for better combustion efficiency and more power. Each set also comes with premium chrome moly wrist pins for added durability.

These pistons are a popular choice among professional engine builders because of their well-built construction and the attention to detail in their design. Manley's unique manufacturing process allows them to machine the skirt and ring grooves in a single operation, which helps ensure the squareness of the ring grooves relative to the piston skirt. This level of precision is crucial for optimal engine performance and longevity.