Manley Performance Platinum Series Piston Set 99.5mm (9.8:1) - Subaru WRX 2006-2014 / STi 2004-2021 (+Multiple Fitments) Offset_+0 Metal matrix catalytic structure -

Metal matrix catalytic structure -

ACT Difference: Forged

* In-Tank design

our engineers are able to properly size and shape the manifold runners and velocity stacks for optimal performance

Manley Performance Platinum Series Piston Set 99.5mm (9.8:1) - Subaru WRX 2006-2014 / STi 2004-2021 (+Multiple Fitments) Offset_+0 Metal matrix catalytic structure -Manley forged and dished pistons for the EJ257 are machined of high strength 2618 material. Each design is lightweight yet robust enough to deliver long service life. Round wire locks, tool steel wrist pins and piston rings are included with every set at no additional charge. A proprietary multi step top ring groove machining process assures optimum control of the groove's size, geometry, flatness and finish. Precise pinhole machining results in an