ZRP Pro Series I-Beam Shaped rods for Subaru 2.0L EJ20 and 2.5L EJ25 are manufactured from the finest raw materials (817M40T steel) to cover even the most Extreme applications. The 817M40T is a popular grade through-hardening alloy steel due to its excellent machinability in the “T” condition. The hardness is in the range of 248/302 HB. The 817M40T – EN24T can be further surface-hardened to create components with enhanced wear resistance by induction or nitriding processing. The tight tolerances in the production process, ensure a perfect fitment while optimizing the oil clearances. The bushings are made from AMPCO 18 material, for excellent resistance to wear and fatigue. Bend and twist is tightly controlled.
Each rod includes ARP L19 cap fasteners that are rated at 260,000psi, optional ARP Custom Age 625+ material 280.00psi available as an upgrade and the whole kit is supplied with ARP moly and full fitting instructions.
Additional machining processes
- Dowel sleeves for perfect fit and accurate re-assembling
- Lipped Cap Relief for improved big-end integrity at extreme application
- Grooves in Thrust Face for weight reduction
Technical Features of ZRP Connecting Rods
- Two-Piece forging for great strength
- I-Beam Shape for extra rigidity
- Shot Peening for improved fatigue life
- Magnaflux Inspection guarantees that the consistency of the forged material meets our high-quality standard
- Double ribbed caps for added support
- Multi Stage Heat Treatment for maximum strength, dimensional stability, and fatigue life.
- CNC machining for superior tolerances, precise as much as 0.0002″
- Center to center is maintained under .001″ tolerance
- Finite Element Analysis (FEA) Computer generated stress analysis of con rods
- Optimal balancing for weight matched sets of ± 1gram