HKS Step 1 Low Compression FA20 Stroker Kit

2013–2020 Subaru BRZ / 2013–2016 Scion FR-S / 2017–2020 Toyota 86

21004-AT003

Overview:

The HKS Step 1 Low Compression FA20 Stroker Kit is a precision-engineered capacity upgrade designed exclusively for the FA20 engine found in the Subaru BRZ, Scion FR-S, and Toyota 86 models from 2013 to 2020. Developed using extensive experience from D1 Drift and time attack events at Tsukuba Circuit, this kit offers a reliable and high-performance solution for enthusiasts seeking to enhance their engine’s displacement and durability.

Built with "Made in Japan" quality standards, this stroker kit supports power outputs up to 550ps, making it ideal for those upgrading their engine internals for high-boost and high-power applications. It provides a cost-effective way to increase displacement without the need for block modifications, ensuring a straightforward installation process.

Key Features:

This kit combines advanced engineering and high-quality materials to deliver improved performance and reliability for the FA20 engine.

• Carefully selected, specially forged pistons crafted from durable raw materials to withstand high power levels.
• Recessed piston design optimized for compatibility with high-lift HKS camshafts.
• Compression ratio optimized through strength analysis and testing, allowing flexibility in tuning and high boost use.
• 3D-designed piston crowns engineered to complement the stock direct injection system and enhance tumble flow.
• Molybdenum-coated pistons reduce internal friction for improved efficiency and longevity.
• High-strength I-beam connecting rods specifically designed to accommodate the longer stroke without compromising durability.
• Special-size crank pins eliminate the need for block modifications, simplifying installation.
• HKS forged crankshaft with a perfectly selected pin journal size, balanced weights, and extended stroke for maximum engine efficiency.
• Maintains the factory 86mm piston bore to preserve block strength and avoid costly machining such as boring, honing, or sleeving.

Construction & Design:

The HKS FA20 Stroker Kit features meticulously engineered components designed to work harmoniously with the stock engine architecture. The forged pistons and connecting rods are manufactured using premium materials and advanced forging techniques to ensure durability under extreme conditions. The piston crowns are shaped with 3D CAD technology to optimize combustion efficiency while maintaining compatibility with the direct injection system.

The forged crankshaft is balanced precisely to accommodate the increased stroke length, ensuring smooth engine operation and longevity. By retaining the factory bore size, the kit avoids unnecessary block modifications, preserving the engine’s structural integrity and reducing installation complexity.

Installation & Fitment:

This stroker kit is a direct fit for the Subaru BRZ (2013–2020), Scion FR-S (2013–2016), and Toyota 86 (2017–2020) equipped with the FA20 engine. The design eliminates the need for boring, honing, or sleeving the cylinder block, making it a cost-effective upgrade.

No cutting, drilling, or special tuning is required to install this kit, allowing for a straightforward upgrade path for enthusiasts looking to increase displacement and power capacity while maintaining reliability.

What's Included:

• Forged pistons with molybdenum coating
• High-strength I-beam connecting rods
• HKS forged crankshaft with extended stroke
• All necessary hardware for assembly

Ideal For:

This kit is perfect for performance enthusiasts and tuners who want to upgrade their FA20 engine internals for higher power outputs, especially those running high boost or competing in motorsports such as drifting and time attack. It offers a durable, reliable solution for increasing engine displacement without compromising the factory block strength.