Requirements for forged pistons...

[auto.guru]

Yah I had 2 pistons go out on me already, correct. Paul was awsome and he replaced it in a day. I don't believe it was because of the tune. Ashley assured me it wasn't and I have total confidence in her. Besides I was in the car while we were tuning it and the computer wasn't showing any knocks and the airfuel was staying awsome. The pistons wern't melted but the rings did break. We just believe it was because of being a high milage engine at 12 psi. I know other people have broken piston rings at that level of boost, so its not to far out of the ordinary. If it happens again I will question that there is somthing else causing it.

people seem to forget....

compression gases push the cylinder downward
compression fumes burn evenly in a smooth flow across the piston top, and start to flow down the sides of the piston skirt.
the combustion gases push BEHIND the piston rings and force them OUTWARD. this is what creates your seal, and scrapes off the oil on your cylinder wall.

if your pushing 12psi, its THAT MUCH MORE pressure pushing outward on that piston compression ring. more pressure = more friction. and running 7000RPM is a greatly increased friction on that ring, will cause it to fail.

This is why we buy expensive, upgraded rings, and dont use cheap factory ones