Wiseco 6598M100 Sport Compact Pro Tru Forged Piston Subaru EJ257 100mm Bore -19cc Dish

The Wiseco 6598M100 is a Sport Compact Pro Tru series individual replacement forged piston engineered for the Subaru EJ257 engine found in the WRX and STI. Featuring a 100mm (3.937 in.) bore diameter and a -19cc four-valve-relief dish design, this piston delivers an 8.9:1 compression ratio — an ideal choice for high-output forced induction builds.

Key Features:

• Forged 2618 High-Strength Aluminum Alloy — Dedicated forgings specific to the final piston shape deliver superior tensile strength and durability under boosted and nitrous conditions
• 100mm (3.937 in.) Bore — Precision CNC-machined to final configuration for tight tolerances
• -19cc Four-Valve-Relief Dish Crown — 8.9:1 compression ratio optimized for turbocharged applications
• 1.209 in. Compression Height — Compatible with 130.5mm rod length and 79mm stroke
• 0.9055 in. Pin Diameter — Chromoly wrist pin and Spirolox retainers included
• Plasma Moly Ring Package Included — Pre-gapped 1/16, 1/16, 3/16 ring set (recommended ring set: 10000VF) provides excellent seal, friction reduction, and long service life
• ArmorGlide Skirt Coating — Proprietary coating reduces friction, resists seizure, minimizes noise, and extends piston life
• Made in the USA — Engineered, forged, and machined at Wiseco's Mentor, Ohio facility
• Piston weight: 376 grams

The Sport Compact Pro Tru series draws on Wiseco's decades of race-proven engineering across Formula 1, NHRA Pro Stock, and rally competition to bring professional-grade performance to your Subaru build.