Coil Spring - 2.5in x 9 500#

The Coil Spring - 2.5in x 9 500# by QA1 is a precision-engineered suspension component built for serious vehicle builders and performance enthusiasts who demand reliability during custom suspension setups. Whether you're engineering a lowered street rod, a competition off-road platform, or a custom chassis build, this coil spring delivers consistent spring rates and predictable handling characteristics. QA1's coil springs are engineered to handle both daily driving demands and track-focused applications without compromising ride quality or longevity.

With a 500-pound spring rate and 9-inch free length, this component provides moderate resistance suitable for mid-range suspension geometry on compact to mid-size vehicles. The 2.5-inch coil diameter allows for integration with standard shock absorber mounting locations and suspension brackets, while the linear spring rate ensures predictable weight transfer during acceleration, braking, and cornering. QA1 manufactures these springs using high-grade steel wire and precision coiling processes, resulting in consistent preload, minimal harmonics, and extended service life even under repeated stress cycles—critical factors when managing suspension geometry in custom applications.

This spring is ideal for builders working on independent front suspension (IFS) conversions, custom A-arm assemblies, or modular suspension platforms where you need a direct replacement or custom-tailored spring rate. Mechanics and suspension tuners select this 500# spring when targeting a balance between comfort and responsive handling—lighter than track-focused 700+ pound rates, but stiffer than factory comfort setups. Verify compatibility with your shock absorber diameter, mounting hardware, and desired ride height before installation to ensure optimal suspension geometry and performance.