Extended Spring Cup w/ Jack Screw

The WEHRS MACHINE Extended Spring Cup with Jack Screw (model WM304S-11) is a rear suspension component engineered for high-performance sport modified applications. This bolt-on upper spring cup accommodates 5-inch coil springs and features an integrated 11-inch jack bolt for precise ride-height adjustment and suspension tuning. Constructed from hardened steel with durable black paint, this component is designed for drivers-side installation and handles the load cycles common in drag racing, circle track, and street performance vehicles where suspension geometry optimization directly impacts handling and launch characteristics.

The 2.5-inch tall design integrates with standard 1-8 inch threaded mounts, allowing integration into existing suspension architectures without frame modification. The included jack screw enables incremental spring preload adjustment—critical for tuners who need to dial in roll stiffness, corner weight, and ride height without disassembling the suspension. The steel construction with corrosion-resistant black paint finish maintains structural integrity across repeated heat cycles and high-G loading events typical of competitive motorsports. At 3.97 lbs, the component carries minimal unsprung weight penalty while delivering the rigidity required for consistent performance.

This component serves drag racers, circle-track competitors, and street performance builders who require adjustable suspension geometry. Suspension tuning at this level depends on precise load transfer and spring preload control—variables the extended cup design directly influences. Competitors and serious enthusiasts rely on quality rear suspension components to achieve consistent launches, predictable weight transfer, and repeatable lap times. WEHRS MACHINE components are recognized in motorsports communities for manufacturing precision and durability under extreme load conditions.

Sport modified suspension systems demand components that balance adjustability with structural stiffness. The extended spring cup design increases load distribution across the spring interface, reducing stress concentration and extending component lifespan in high-cycle applications. Proper spring cup geometry also preserves spring rate accuracy—essential when suspension tuners have calculated spring rates and ride-height targets for optimal vehicle behavior. This is a core suspension tuning component, not a cosmetic upgrade, and belongs in builds where suspension performance directly determines competitive success.