Each spring is loaded in the spring tester at the factory, then compressed and the CNC load cell measures the force for a variety of spring lengths. This allows BMR to offer a LIFETIME WARRANTY against spring sag.Blending aesthetics and performance, BMR has designed the SP091 for the handling crowd who regularly use their cars on the road course or for autocross. These springs will drop the front of your Fourth Gen F-Body 1.25-inches, and feature a fine-tuned spring rate to give you great handling and a smooth ride. The 725 lb/in spring rate, which offers plenty of support, keeping the body flat and level in the corners. The lowered stance and increased spring rate decreases body roll and gives you a lower center of gravity for increased driver control in aggressive cornering situations. Combine this with BMR adjustable sway bars and you have the ultimate in handling and performance. When performance and looks are a must, rely on BMR's suspension!BMR's suspensions SP091 lowering springs are available in red powdercoat for long-lasting good looks. Installation time is about 2-3 hours. Proudly made in the U.S.A.