When we dyno, we can now see what A/F gave us peak HP at specific rpm. On the dyno last week, we saw that at 7500 rpm, with .300 mains, we where making 92 hp at 13.3:1. We switched jets our to .290s, and at 7500rpm we made 95hp at 14.0:1 (or something like that; I'd have to go back and look at the data to be accurate). Anyway, we found it easier to tune using the WEGO than just guessing what the motor wanted. We also use a Relative Air Density gauge for initial setup, then fine tune with the data acquasition, based on what our dyno session data showed vs what it shows "day of" event. There are no practice runs at Speedweek, just get in line and try again.