C/O Spring - 4.125 ID x 11 300# Silver

The QA1 Coil-Over Spring 4.125 ID x 11 300# Silver is a precision-engineered coil spring designed for suspension systems demanding responsive handling and consistent load support. This spring is ideal for serious builders and tuners working on street performance cars, road-course vehicles, and suspension-focused platforms where spring rate selection directly impacts driver feedback and chassis balance.

Manufactured from steel with a silver powder-coat finish, this spring resists corrosion while maintaining consistent stiffness across extended temperature ranges. With a 300 lb/in spring rate and 11-inch length, this QA1 coil-over component delivers the tuned compliance needed in high-performance vehicle setups. The 4.125-inch inner diameter accommodates standard coil-over shock body designs, making it versatile for various applications.

Off-road applications, autocross setups, and track day builds frequently employ springs in this stiffness range to achieve responsive handling while maintaining adequate ride comfort. Each spring is individually produced to QA1's tolerances, ensuring repeatability when paired with matching components on the opposite side of the vehicle. This coil spring is an excellent choice for those looking to enhance their vehicle's performance and handling characteristics.