I move right with the alky cars with the dewpoint and humidity changes, about double what they move for ambient temp and barometer, and about double from "best air of the season to worst air of the season".
And I'm talking about the few racers that I can pick my dial from watching their runs, and the ones that I compare changing conditions with.
Barometer only affects it little for me being at 15:1 static, I run the carb rich so ambient temperature moves me more than barometer, so National Event type tracks can trick you up with reflected ambient heat you won't see at your weather station.
10 minutes of sun on an overcast day at Indy is a .04 slower ET for me, on the 1/4 mile.
Just about everywhere once the sun moves to about 4 o'clock, standard time, the car picks right back up to where it was for the early morning shots. Some of the alky cars move with me, some don't, in those cases, I suspect it is a different mixture setup and temperature range that racer runs it in.
Ya gotta keep an eye on the sunload on the track, traction suffers in the sun too.
Anytime the dew starts collecting on the cars, I can dial up about .02-.03 from the best I've run.
At night tracks, when you see a haze around the track lights, the dew is coming, if the temps continue to fall, the haze will clear up and my car will get right back where it was.
Heck, some of that almost makes sense.....?
