ft... A for NA is pretty good but I have found some inaccuracies in it. For example it says this, "With the exception of near closed throttle position, an increase in engine speed will produce an increase in manifold pressure."
As far as I know, a decrease in engine speed will produce an increase in manifold pressure! They also didn't explain preignition and detonation very well. They gave the impression that detonation was more dangerous than preignition. That's actually the opposite! You can run an engine with moderate detonation for quite a while, but if you have preignition it can ruin an engine in seconds!