SUBARU 2.0L WRX-STi EJ20 / EJ205 (1998-Up) w/ 4032 Pistons Alloy & H-Beam Rods


  • Pistons made from 4032-T6 high-silicon / low-expansion alloy
  • • Side gas ports for better ring seal
  • • 9310 alloy wrist pins / Cylindrical shape
  • • Anti-detonation grooves to protect the first rings
  • • Gas pressure accumulator groove for better ring seal and vibration relieve
  • • Offset pins for quiet operation
  • • Over size and deeper valve pockets
  • • Round Skirt Style
  • • Pro-Select Total Seal 1.00mm x 1.20mm x 2.00mm ring set included
  • Classic Series Rods H-Beam Shape w/ Ribbed pin end
  • • ARP 2000 rod bolts rated to 220.000psi (3/8″)
  • • AMPCO bushing with radial groove
  • • Lipped cap relief for improved big-end integrity at extreme application
  • • Shot Peening for improved fatigue life
  • • Multi Stage Heat Treat for maximum strength and dimensional stability
  • • Bend and twist is tightly controlled.
  • • 2 piece forgings from high tensile steel 4340
  • Crankshaft Manufactured from 4340 Precision Billet Steel
  • • Gun drilled crank pin and counterweights to reduce weight and rotating mass.
  • • Dual passage – straight through oil feeding. Each journal having two main sources of oil feed. providing enhanced lubrication at higher RPM.
  • • Nitride process for hardening & Multi-stage Heat Treatment for superior wear resistance
  • • Shot peening for improved fatigue resistance
  • • Micro-polishing for longer bearing life
  • • Journal radium disperse load stress