Spring 4in Coil-Over 2.5in ID

The Spring 4in Coil-Over 2.5in ID by EIBACH represents a precision-engineered suspension component designed for enthusiasts and mechanics pursuing serious ride height adjustment and chassis tuning. This coil-over spring is built to replace or upgrade factory spring rates on performance-oriented builds where lowering, load support, and driver-tuned suspension geometry are priorities. Whether you're fine-tuning a street car, prepping a track platform, or engineering a custom build, this EIBACH spring delivers the controlled compliance modern suspension systems demand.

The 4-inch free length with a 2.5-inch inner diameter (ID) specification indicates a progressively wound or linear rate design optimized for coil-over damper applications, where spring and shock work in concert to control body roll, improve weight transfer, and maintain tire contact through corners. At 1.16 pounds, this compact spring is lightweight yet rigid enough to support sustained load cycles without fatigue or permanent set degradation. EIBACH's manufacturing precision ensures consistent rate characteristics across multiple compression cycles, critical for reproducible setup across test sessions or daily driving where suspension behavior must remain predictable and tunable.

This spring suits builders integrating aftermarket coil-over kits, upgrading OEM suspensions to performance-grade dampers, or replacing worn originals on existing setups where spring rate matching is non-negotiable. Verify inner diameter clearance and free length compatibility with your specific damper body before installation; coil-over applications require precise ID tolerances to prevent binding or lateral movement under load. Installation typically requires spring compression tools and proper safety equipment; paired with valved dampers tuned to your spring rate, this component enables the complete suspension tuning authority that separates dialed-in vehicles from stock platforms.