Forged Piston & Rod: Subaru EJ20/EJ25 Performance Application Case

2026-04-30

🔥 HIMYCAR Forged Piston & Rod: Subaru EJ20/EJ25 Performance Application Case

Customer requirements

A Subaru Impreza WRX STI owner (EJ257 2.5L turbo) aimed to build a reliable 500+ hp street-race engine，

replacing weak factory cast internals that failed under 1.8bar boost and frequent track use. The goal: max power, minimal failure risk, daily drivability.

Core Upgrade: HIMYCAR Forged Piston & Rod Combo

Pistons: 4032 aluminum alloy, 99.5mm bore (oversize 100mm), 8.5:1 compression, anti-friction skirt coating
Rods: 4340 (40CrNiMoA) aircraft-grade steel, H-beam design, shot-peened & magnafluxed, reach L19 forged rod bolts

● Performance result: The quality is superb and the items fit perfectly

High Boost Ready: Supports 2.0bar+ boost, safe for 600+ hp with proper tuning.

Precision & Reliability: CNC-machined to ±0.001mm tolerance;

Balanced set (±1.5g) reduces vibration.

For Subaru EJ20/EJ25 enthusiasts chasing 500–700 hp with bulletproof reliability, HIMYCAR forged piston & rod is the ultimate upgrade.

It transforms the fragile stock engine into a high-performance powerhouse, perfect for street, drag, rally, or track use.