How do you find the limits of the fuel you're running without the help of the knock sensor? I've always just assumed it was tuning mojo that came with experience. The wideband lets you dial in the fuel curve perfectly, but the knock sensor lets you figure out what the maximum boost level you can run is, say, on pump gas. Keeping the a/f ratio at around 11:1 you crank the boost until you start getting knock then turn the boost back down a bit to get rid of it. I mean, that's a simplified tuning strategy for idiots (like me) and it doesn't account for timing, and fuel fine tuning after that, but without the knock sensor how do you know when you're reaching the limitations of your fuel on your setup?