Audi is adding new glass fiber-reinforced polymer (GFRP) suspension springs to a new model this fall that is said to reduce sprung and unsprung mass. With the new GRFP spring being about 40 percent lighter than a comparable steel spring, Audi says the vehicle can be tuned for more precise driving.
The new GFRP springs, which will debut on an "upper mid-size model," weigh approximately 3.5 pounds compared to the 6.0-pound steel springs they replace. About half of the approximate 9.7-pound overall weight savings is unsprung mass, according to Audi. The GFRP spring also features fewer coils compared to a comparable steel spring.
“The GFRP springs save weight at a crucial location in the chassis system. We are therefore making driving more precise and enhancing vibrational comfort,” said Dr. Ulrich Hackenberg, Member of the Board of Management for Technical Development at AUDI AG, in a release.
The GFRP springs are made by twisting long glass fibers together, which are impregnated with an epoxy resin. Additional fibers are mechanically wrapped around the core at alternating 45-degree angles plus and minus the original core to counteract the stresses acting on it. The springs are then cured at high temperatures.
In addition to more precise suspension tuning, other benefits include lack of corrosion and being impervious to cleaning chemicals and road grime. Audi also says the GFRP springs require less energy to manufacture.
It remains to be seen how the polymer springs hold up over time, but we can see how the new springs perform when they arrive on a new model later this year.