There are prop slip calculators here, there and everywhere, but they don't mean as much if you don't enter the right numbers into the equation. I run a bravo 1xs and they are known to be loose in pitch #'s. So if I am running a 30, do I use 28,28.5,29 in the slip calculator. What if I had cup added, do I add or subtract a .5-1" pitch in the formula?