The A/F numbers are from the high gear shift through the traps. The 1050 showed high 12's through the same range. I initially made 4 passes with the 1050, switched to the 780 for 2 passes before it started to sprinkle. When the rain stopped and they dried the track, Wanting to see if it was carb, weather or engine causing the slow down I switched back to the 1050 and made 2 more passes after trying the 780 and the car was right back running 10's. My A/F sensor is mounted in my RH header, just after the merge area. I do have an 18 inch extension behind it so hopefully there is no reversion messing with the sensor.