Engines and Components› Pistons and Piston Rings

HKS

Forged Piston Kit 92.5mm Bore for Subaru EJ20 2016cc

$910.35

SKU: 21003-AF002

In Stock
In Stock
Ships by Aug 1
Free Shipping over $100
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Description

The HKS 21003-AF002 forged piston kit is engineered for Subaru EJ20 engines, offering a displacement of 2016cc (2.0L). The pistons themselves are constructed with a 92.5mm bore and a 23mm pin bore. The piston tops are treated with nickel plating for enhanced durability, while the piston skirts feature an Ober coating to reduce friction. The compression ratio varies depending on the application, noted as GK t = 1.4 = 8.0 for GC8ver.III ~ VI and GK t = 0.7 = 8.1 for GDB BE5. Installation notes indicate that full-flow processing is unnecessary for this kit. Specific fitment includes Subaru Impreza WRX/STI models with the EJ20 engine, specifically the 2.0L Turbo GT AWD (GC8) from 1994-2000 and 1998-2000, as well as Subaru Exiga models from 2008-2015. Please confirm exact fitment for your vehicle before purchase, as returns due to incompatibility may not be accepted.

MIA's Description

The HKS 21003-AF002 is a forged piston kit designed for Subaru EJ20 engines. This kit features a displacement of 2016cc with a bore of 92.5mm and a pin bore of 23mm. The pistons have a nickel plating on top and an Ober coating on the skirt.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandHKS
Part Number21003-AF002
CategoryEngines and Components

Buy with Confidence

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy