What makes INTRAX springs better? INTRAX designs most of its lowering kits with progressive rates, to satisfy the two features you have asked for most. First, the lowered look. Most other brands springs are linear rate, as this is cost-effective but does not necessarily provide the visual effect you desire. By designing a progressive spring, we achieve the lowered look while maintaining safety standards of spring preload at suspension droop. The second requirement is ride quality. Since most of you identified that you drove 90 percent of your mileage to and from work, you wanted to retain some ride quality enjoyed with OE springs. If you are driving to work on a racetrack, Sport or Race springs from other brands may be for you. INTRAX progressive springs provide high performance looks and comfortable ride quality. INTRAX creates the finest springs, from start to finish. INTRAX springs begin the forming process with cold winding to the most exacting standards. Within two hours of forming, springs are stress relieved in an oven (not to be confused with heat treating), and then shot peened to remove surface imperfections and further relieve internal stress. This can extend service life of a spring up to 200 percent or more. Next, the spring is blocked (wound to a longer length than required, and set in a hydraulic press to obtain designed free length). This eliminates the settling other brands require, due to the lower cost of their production processes. Finally, springs are Phosphate coated for corrosion resistance, and electrostatically powder coated to ensure a lifetime of outstanding looks.