The I-Beam Connecting rods for BMW S58B30 are crafted from premium 4340 high tensile steel, optimized for high performance and extreme durability. Designed with "straight cut" pin ends, these rods are compatible exclusively with aftermarket pistons. The bushings, made from AMPCO 18 material, offer excellent wear and fatigue resistance, featuring radial grooves for oil retention. The rods undergo shot peening to relieve material stress and multi-stage heat treatment to enhance rigidity. Precise production processes ensure perfect fitment and optimized oil clearances, with controlled bend and twist. Each rod includes ARP 2000 cap fasteners rated at 220,000 psi, with an optional upgrade to ARP L19 material rated at 260,000 psi. The kit is supplied with ARP moly and comprehensive fitting instructions.

Additional Machining Processes

• "Straight Cut" Pin End – Suitable for aftermarket pistons
• 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

• I-Beam Shape for extra rigidity
• Two-Piece forging for great strength
• Shot Peening for improved fatigue life
• Magnaflux Inspection ensures high-quality material consistency
• 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 .001″ tolerance
• Finite Element Analysis (FEA) for stress analysis of con rods
• Optimal balancing for weight matched sets of ± 1 gram