The I-Beam “Heavy Duty” series connecting rods for Nissan Skyline RB25/RB26 are designed for high horsepower and boost applications. Constructed from 4340 high tensile steel, these rods feature a specially optimized shape for enhanced performance and durability. The bushings are made from AMPCO 18 material, providing excellent wear and fatigue resistance, with a radial groove that acts as an oil reservoir. Each rod is shot peened to relieve material stress and undergoes multi-stage heat treatment to increase rigidity. Precision manufacturing ensures tight tolerances for optimal fitment and oil clearances, with controlled bend and twist characteristics. Each rod is equipped with 3/8 ARP 2000 cap fasteners rated at 220,000 psi, with optional ARP L19 material available as an upgrade. The complete kit includes 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 in extreme applications
• Grooves in thrust face for weight reduction

Technical Features of ZRP Connecting Rods

• I-Beam shape for extra rigidity
• Two-piece forging for enhanced strength
• Shot peening for improved fatigue life
• Magnaflux inspection to ensure consistency of forged material
• Double ribbed caps for added support
• Multi-stage heat treatment for maximum strength, dimensional stability, and fatigue life
• CNC machining for superior tolerances, precise to 0.0002″
• Center-to-center maintained under 0.001″ tolerance
• Finite Element Analysis (FEA) for computer-generated stress analysis of connecting rods
• Optimal balancing for weight-matched sets of ± 1 gram