Wiseco K599M9975 Forged Piston Kit Subaru EJ25 DOHC 99.75mm Bore

The Wiseco K599M9975 is a high-performance forged piston kit engineered specifically for Subaru EJ25 2.5L 16V DOHC naturally aspirated engines found in the Impreza RS, Forester, and Legacy models. This complete piston set delivers the strength and reliability demanded by performance enthusiasts and engine builders.

Key Specifications:

• Bore: 99.75mm (3.927 inches) - 0.010 inch oversize
• Compression Height: 30.25mm (1.191 inches)
• Dish Volume: -23cc
• Compression Ratio: 8.7:1
• Pin Diameter: 23mm (0.905 inches)
• Pin Length: 2.500 inches
• Average Weight: 367 grams per piston

Performance Features:

• Forged from high-silicon aluminum alloy for exceptional strength and durability
• Engineered and manufactured in the USA at Wiseco's Mentor, Ohio facility
• Advanced forging process with extensive heat-treat and finishing procedures
• Computer-engineered piston skirt profiles minimize cylinder wall friction
• Lightweight forging provides instant throttle response and maximum torque

Complete Kit Includes:

• Pre-gapped piston rings (Ring Set Part #9975VF)
• Wrist pins (Pin Part #S805)
• Circlips (locks)

Wiseco has been the world leader in high-performance forged pistons for over 80 years, trusted by racers and enthusiasts across automotive, powersports, and marine applications. These pistons outperform cast and hypereutectic alternatives, delivering tighter tolerances and superior strength for demanding performance builds.