Chill on one side=wind direction
Stays wet=high humidity
Blown sideways=might not want to run
I like it Dean! One of the better drag race tuners I know once told me all he ever uses is an air density gage and a mood ring...
Some of those weather stations can get pretty elaborate, I saw one that tracks moon phases and had a built in tide-table
What I've found is just like using a datalogger, the trick is to know what to do with all that information. When condition are thus, what knob do i tunrn and how much? Dragracers have an advantage of being able to build a log book with previous weather conditions, altitudes for the various tracks, and the jets you used in that engine to get a good looking plug and run you lowest ET and highest mph. Personally, for my drag car I use a Barry Grant air density gage, my log book, and (don't laugh) one of those three gage weather stations my grandmother used to have hanging on her wall for decoration. I tune on gasoline fueled drag cars with carbs, the plugs read pretty easy and I get three qualifying passes. The worst i've ever had happen with the normally aspirated cars i've raced is a lean condition at the top end, no problem, you just get out of the throttle and changet he tune in the pits. I'm probably stating the obvious, but LSR car tuners don't seem to have the luxury of making a "jetting pass".
Aside from my own drag car, I've crewed on a top alcohol dragster for a few years, then an injected nitro dragster, and once on a top fuel dragster. For those cars you have to get the tune pretty close, or the car is real lazy and fat or like the blown and blown fuel LSR cars, stuff melts in a hurry if it's lean.
All three crew chiefs I worked for on the faster cars used this wooden box put together by Ralph Gorr Fuel systems. In fact, I've see several pro teams using them or something real similar. It's a bit "old school" I guess, but the method seems to work. It has an aircraft-grade alitimiter, some device that measures water content of the air, a thermometer, and a little programable calculator (like a mini-computer) Gorr pre-programs some weather versus lbs per hour of fuel formulas into the mini-computer for you. Also included is an instruction booklet that includes a charts that relates to your mechanical fuel injection set up, your particular pump and high-speed lean out. The key to tuning those cars seems to revolve around having the entire fuel system wet flowed to get some accurate baseline parameters from which to work. You show up to the meet with the tune real close, instead of starting from way out in left field somewhere wasting precious track time trying to figure it all out.
The crew chief checks the weather and predict what it might be for our first pass, consult the ouji board and makes fine adjustments, then cross his fingers. He might take some timing away if he thinks we are a touch on the lean side. Some guys read the warm up plugs after the engine has some heat in it and seen some load while seating in the clutch in the pits, but that is tricky.
