H5S. TW - Motorsport's most advanced spring material. Swift made a name for itself on the tracks of Asia, Europe, and U. S. by defying all accepted concepts and speculations about the future, if any, in coil spring science. When many other company were looking at expensive and brittle titanium composites to create the next evolution of springs, Swift was looking at reinventing the entire science of coil spring dynamics. Swift saw that most others are using the old regular silicone chrome material, which was not strong enough. It used a heat tempering method that damaged the strength of the material that requiring more coils, in turn, more weight. The material was also suffering from a short life span. With springs like this leading the industries, Swift saw room for improvement. Swift's R & D team created material, called H5S. TW, which is stronger then regular silicone chrome material. Because of this material, we could make the spring wire thinner, and could wind the springs with fewer coils, which greatly decreased weight while dramatically increasing available stroke. Barrel Design: Isn't the barrel design heavier? Not on Swift. Still one of the lightest!! All of Swift Standard 10" and longer Coilover springs are barrel design; the design is to solve all spring bowing problems. With bowing springs, you can expect spring rate inconsistency, and rubbing against shock body that would lead to damages on the shock adjusting perch thread. One approach would be to increase the number of coils on the springs. With more coils on the spring, you will experience less bowing motion. This is the easy and cheaper method to solve the issue. But the downside of this method is a decrease in suspension stroke, increase in un-sprung mass, and will effect the overall movement of other suspension components. Unlike others, Swift designed barrel springs with one common rule, which is all the barrel springs design have a maximum of 4" OD. Because most other manufacture do not design their barrel springs with this rule. Most of their barrel springs outside diameter will differ from one rate to another. This creates a hard time for racers to test and see which rates will fit and which rate does not. a heavier rate spring tends to interfere with the suspension A-arm or other suspension components. Generally speaking, the barrel designed springs tend to be heavier in weight than straight shape springs, but Swift coil springs will never have this problem because of our world leading coiling technology . As you might know, United States are the largest racer populated country in the world. Through our experiences from extensive testing in world class racing in Europe and Asia, we have great confidence that we can provide the same results in the US. Swift specifically designed a standard measurement race springs to accommodate American race industries including oval track racing, and drag racing. By knowing the main characteristics that American racer demands, we designed and engineered the standard measurement springs based on data that we had collected through racers that are at the top of their sport. a slight difference in design then our metric coilover springs. While most track racers have already began the ritual of swapping their springs, many swap from one brand to another let you notice the stiffness only as being either softer or harder. What if a spring could change other dynamics, such as a noticeably lighter unsprung mass, smoother weight transferring, better ride quality, lower tire temperature, and increased ability to anticipate vehicle reaction? Like most racers, Swift team hates to hear "what if", so they built the "what if" into reality. All of Swift Springs are made with our exclusive material called H5S. TW. Without this specially designed material, our light weight spring design would not exist. All of Swift 10 or longer springs are barrel design; the design is to solve all spring bowing problems. With bowing springs, you canPit Stop USA offers Swift Springs 12" x 2-1/2" Barrel Coil-Over Race Spring - 325 lbs. 120-250-325B at low everyday prices. Be sure to check out all of our products from Swift Springs including Swift Springs 2-1/2" I.D. x 12" Tall Coil-Over Springs.