What is NA when you are talking about the cars? I am not familar with this term. Sorry for the ignorance on this.

NA stands for Naturally Aspirated. This is basically most cars. Your average honda civic, toyota camry, and chevy camaro are all naturally aspirated. If a car has any sort of turbocharger, sequential(twin) turbocharger, or supercharger, it is said to have Forced Induction. This also commonly known as "running boost" and/or [insert favorite slang term here]. I'll leave out the explanation of how forced induction works, although if you ask, I'm sure there will be dozens of responses(none of them the same too, I'll bet https://www.nopistons.com/forums/pub...IR ) Hope that clears things up!

Thank you that helped.