Manley 04+ Subaru WRX/STi EH257 99.50mm STD Bore 9.8:1 Dish Extreme Duty Piston Set of 4

If you're rebuilding the engine in your 2004 and up Subaru WRX or STi, these Manley Performance Extreme Duty Piston Sets are a solid choice for serious builds. These pistons are designed for the EH257 engine, featuring a 99.50mm standard bore and a 9.8:1 compression ratio with a dish top. Manley is well-known among professional engine builders for making pistons that hold up under demanding conditions.

What sets these pistons apart is the material and construction. They start with domestic 2618 alloy forgings, which are known for their strength and ability to handle high performance. Manley also applies their proven cam and barrel skirt profiles, which help generate power while being easier on your cylinder walls. The ring lands and grooves are machined to very strict standards, which is key for getting a good seal from your piston rings and making more power. Plus, they come with premium chrome moly wrist pins, and for some part numbers, Manley offers upgrades to even stronger alloys like 9310 or Turbo Tuff/DLC for extra durability.

Manley's unique manufacturing process allows them to machine the skirt and cut the ring grooves in one operation. This ensures the ring grooves are perfectly square to the piston skirt, which is crucial for optimal ring seal and engine longevity. Keep in mind that these pistons are not CARB approved and cannot be shipped to California. If you're aiming for a high-performance build, these Manley pistons are built to perform and last.