nitrous ring gapping

There is more to piston design than the material they are made from. KB positions the top ring groove higher on the piston to cool it. This helps to reduce detonation, but it also weakens the top of the piston and causes the top ring to run hotter. To compensate for running the ring at a higher temperature, you have to run a larger end gap. If the rings butt, the piston will break.

The KB tech articles explain this in great detail. I am not trying to say these are bad pistons, or that you shouldn't use them with nitrous. It's just that they require special setup and even then there is a chance something could go wrong.