What are the Advantages of Forged Aluminum Pistons?
Forged aluminum pistons become a necessary upgrade when using a nitrous oxide (NOS) system to generate power increases of greater than 35 percent. Running a nitrous oxide system causes large combustion chamber pressures and temperatures, and the use of forged pistons prevents piston burns from occurring. This type of event transpires when the cylinder conditions allow detonation to take place. Forged aluminum pistons are considerably stronger than steel pistons, and are better able to handle the increased forces that burning NOS produces.
For more info, see How Nitrous Oxide Increases a Vehicle's Performance