Speedmaster Forged Pistons are designed for naturally aspirated or moderate nitrous applications, and they are made from 4032 aluminum, making them up to 20 percent lighter than traditional forged pistons. The forging process of these pistons eliminates metal porosity, improves ductility, and enables the piston to run cooler than a cast piston. Engineered to run tighter piston-to-wall clearances and for longevity, forged pistons are ideal for street performance, endurance racing, and drag racing applications.