Engines and Components› Pistons and Piston Rings

HKS

Forged Piston Kit 92.5mm Bore for Subaru EJ20 2016cc

$910.35

SKU: 21003-AF002

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

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.
Show original supplier 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.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

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

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy