CP Pistons Forged Piston & Ring Set Subaru BRZ FA20 86mm Bore 10.5:1 CR - Set of 4 | SC7407-4

Overview

The CP Pistons Forged Piston & Ring Set for the Subaru BRZ FA20 engine is a precision-engineered performance upgrade designed for enthusiasts and builders demanding maximum reliability under high-stress conditions. Featuring an 86mm bore diameter and a 10.5:1 compression ratio, this set of 4 forged pistons is purpose-built for naturally aspirated builds, forced induction applications, and competition use where stock cast pistons simply cannot keep up. Whether you're building a street sleeper or a dedicated track car, CP Pistons delivers the strength and consistency that serious engine builders trust.

Key Features & Benefits

• Forged 2618 or 4032 Aluminum Construction — Dramatically superior strength and fatigue resistance compared to OEM cast pistons, capable of withstanding extreme cylinder pressures and thermal stress cycles
• 86mm Bore Diameter — Precision-machined to exact tolerances for a proper seal and optimal ring seal performance in stock or lightly bored FA20 applications
• 10.5:1 Compression Ratio — Optimized for high-performance naturally aspirated or mildly boosted builds, maximizing combustion efficiency and power output
• Full Ring Set Included — Matched performance ring pack included with each set, eliminating the guesswork of sourcing compatible rings separately
• CNC-Machined Precision — Each piston is machined to exacting tolerances ensuring consistent weight matching across all four pistons for a smoother, more balanced rotating assembly
• Gas Ports & Coatings (where applicable) — Advanced piston design features gas ports and thermal/friction-reducing coatings to improve ring seal and reduce parasitic losses
• Designed for FA20 Architecture — Engineered specifically around the Subaru FA20 flat-four engine geometry, ensuring proper pin height, compression height, and valve relief clearances

What's Included

• 4x CP Forged Pistons (86mm bore, 10.5:1 CR)
• 4x Matched Performance Ring Sets
• CP Pistons documentation / spec sheet

Specifications

Fitment & Compatibility

This CP Pistons forged set is specifically designed for the Subaru BRZ and Toyota 86 (GT86/FRS) equipped with the FA20 naturally aspirated boxer four-cylinder engine. Fitment covers model years where the FA20 platform was used (2012–2021 for BRZ Gen 1; verify bore and compression specifications with your engine builder before ordering). These pistons are ideal for engines being freshened, rebuilt, or taken beyond stock displacement with a light bore. Always confirm wrist pin diameter, compression height, and deck clearance with a qualified engine builder to ensure proper fitment for your specific build.

Cross-reference OEM part numbers and bore measurements before ordering. Not compatible with the FA24 engine found in 2022+ BRZ/GR86 models.

Installation

Installation of forged pistons requires a complete engine disassembly and should be performed by a qualified engine builder or machine shop. The cylinder bores must be properly measured, honed, and finished to the correct bore size and surface finish prior to installation. Proper piston-to-wall clearance, ring end-gap filing, and rod bearing selection are critical steps that must be completed by an experienced professional. This is not a bolt-on component — professional engine assembly is strongly recommended to ensure long-term reliability and performance.

Is this set CARB compliant? Forged piston sets are internal engine components intended for closed-course competition or off-highway use. Check local emissions regulations before use on street-registered vehicles. These pistons do not alter external emissions equipment but may affect emissions compliance depending on your build configuration.