Forged from high-silicon aluminum alloy for maximum strength and dependability Wiseco offers a complete range of popular piston models and years for both trail and racing applications Durability, longevity and increased horsepower Innovative forging design and piston skirt provide maximum horsepower and torque Features forged pistons, rings, wrist pins, and circlips These high-tech piston designs offer maximum compression ratios, ultra-stiff strutted forgings, and titanium nitride-coated rings, which all add up to more power that is sustained longer Each piston is E-Coated on the crown, ring grooves, and pin bore, for maximum wear resistance and protection from micro-welding, galling, and detonation GP Series parts generally have less machining on the outside, which helps seal up the bore for increased compression Additionally, boost ports are removed for a more predictable powerband and increased pull on the top end Cylinder sleeves must be purchased separately. Service intervals may be increased with Racer's Choice pistons over conventional Wiseco pistons, and are for expert racers and tuners only.