What is the compression ratio achieved with these pistons?

These pistons are designed to achieve an 8.5:1 compression ratio when used with the specified 79mm stroke and the -17cc dish. The final compression ratio can vary slightly based on cylinder head volume and gasket thickness.

What is the benefit of the moly skirt coating?

While not all part numbers feature it, select Manley pistons include a moly skirt coating. This coating helps reduce friction and wear between the piston skirt and the cylinder wall, contributing to improved engine longevity and performance.

Are these pistons compatible with all EJ257 engines from 2004 onwards?

This piston set is designed for the EJ257 engine found in 2004 and later Subaru WRX and STi models. It's always recommended to confirm the specific engine code and dimensions for your vehicle to ensure proper fitment.

Specifications

Brand: Manley Performance
Part #: 632801CE-4
UPC: 807298109046

Manley 04+ Subaru WRX/STi (EJ257) 79mm Stroke 99.55mm Bore 8.5:1 -17cc Dish ED Piston Set

Name: Manley 04+ Subaru WRX/STi (EJ257) 79mm Stroke 99.55mm Bore 8.5:1 -17cc Dish ED Piston Set
Brand: Manley Performance
SKU: manley-performance-manley-04-subaru-wrx-sti-ej257-79mm-stroke-99-55mm-bore-8-5-1-t14-313239
Price: 963.51 USD
Availability: BackOrder

$963.51

On Backorder

Order now to reserve yours — we'll ship as soon as stock arrives. Full refund if we're unable to fulfill.

Manley 04+ Subaru WRX/STi (EJ257) forged piston set. Features 2618 alloy forgings for superior strength and durability.

Key Features

Fits 2004+ Subaru WRX and STi models with the EJ257 engine.
Constructed from domestic 2618 alloy forgings for superior strength and performance.
Features a 99.55mm bore and a 79mm stroke, designed for an 8.5:1 compression ratio.
Includes a -17cc dish for precise compression tuning.
Utilizes proven cam and barrel skirt profiles to optimize power and reduce cylinder wall wear.
Machined to exacting standards for enhanced ring seal and increased power.

This piston set is specifically designed for 2004 and later Subaru WRX and STi models equipped with the EJ257 engine. Always verify compatibility with your specific vehicle's engine configuration.

⚠️ CA WARNING: This product can expose you to chemicals known to the State of California to cause cancer and/or birth defects or other reproductive harm. Learn more

Secure CheckoutFast Shipping631-982-0042

About this part

Product Details

Built from domestic 2618 alloy forgings, these Manley pistons are designed for the demanding EJ257 engine found in 2004 and later Subaru WRX and STi models. With a 99.55mm bore and a 79mm stroke, they are intended for builds aiming for an 8.5:1 compression ratio, featuring a -17cc dish to help achieve that target. This specific set is engineered to handle the stresses of high-performance applications, making them a popular choice among professional engine builders and tuners.

Manley's commitment to performance is evident in the details. The pistons utilize proven cam and barrel skirt profiles, which help generate substantial power while minimizing wear on the cylinder walls. The ring lands and grooves are machined to exacting standards, ensuring a superior ring seal for improved power output. Each set includes premium chrome moly wrist pins, with options for upgraded alloys like 9310 and Turbo Tuff/DLC for even greater durability in extreme conditions. Manley's unique fixturing process allows for skirt turning and ring groove machining in a single operation, which guarantees ultimate squareness between the ring groove and the skirt for consistent performance.

This piston set is a significant upgrade for anyone rebuilding or modifying their EJ257 engine. 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.