You are correct. I am trying to understand the constraints and considerations that are required when tuning a turbo charged engine. I am hoping to learn the principals, not the specifics, so that when somebody discusses tuning modifications that I understand why, not just how much

Stavros made an excellent point very near the beginning - many people refer to BD10 etc etc without even considering what they do to lift or duration.

I am trying to understand how people come up with the ideas, not just which bits!

JJ