Manley 04+ Subaru WRX/STi (EJ257) 83mm Stroker 99.5mm STD Size Bore 8.5:1 Dish Piston Set

Manley Performance is well-known for building strong engine components, and their "Platinum Series" pistons are a prime example of that commitment. If you're working on an 04+ Subaru WRX or STi with the EJ257 engine and looking to build a more powerful stroker setup, this piston set is designed to handle the demands. These pistons feature an 83mm stroke, a 99.5mm standard bore size, and an 8.5:1 compression ratio with a dish top, making them a solid choice for a performance build.

What sets these pistons apart is the material and the machining. They're forged from domestic 2618 alloy, which is chosen for its superior strength and ability to perform under high stress. You'll also find that they come standard with premium Chrome Moly wrist pins, and for some part numbers, Manley offers upgrades to even more durable alloys like 9310 or Turbo Tuff/DLC for added longevity. The machining is equally impressive; Manley uses unique fixturing to ensure the skirt turning and ring groove machining happen in a single operation. This process guarantees ultimate squareness between the ring grooves and the skirt, which is crucial for an enhanced ring seal and ultimately, more power. The cam and barrel skirt profiles are also carefully designed to generate substantial power while minimizing wear on your cylinder walls.

When you're building a performance engine, attention to detail matters. Manley adheres to strict standards for the piston ring lands and grooves, which directly contributes to better ring seal. This set is designed for stroker applications, meaning it's intended to work with crankshafts that have a longer stroke than stock, allowing for increased displacement. Keep in mind that these pistons are not CARB approved and cannot be shipped to California. For a serious engine build, this set offers the strength and precision that professional engine builders rely on.