[roastbeef]

while on the subject of tires, you mentioned using a tire pyrometer a few times and talked about temperature spreads. i've learned that temperature of the tire tread isn't super relevant. you basically have to come into the hot pits as you complete a hot lap and have someone right there waiting to take temps. even then, it isn't super important. mostly because by the time you come in, get your pyrometer out, etc., the tread temps have largely dissipated throughout the tire carcass. i was told this by a more experienced driver i met at a track day who actually had a tire pyrometer (longacre, very nice), and this was reaffirmed in a "tune your car's handling webinar" i listened to with ross bentley and jeff braun (experienced race engineer).
i was glad to become bestowed with this info before i dropped $300 on a pyrometer. it is a tool that has its place, but only if used properly. even when used properly, it is a small piece in the puzzle of tires, tire temps, and pressure.

the tire manipulation in the picture is normal and natural to an extent. since you're running 19's your margin of error is going to be slimmer on tire pressure. you have less sidewall to play with, and getting it just right is going to be tougher. its good that you are taking track temps and it sounds like you are really enthusiastic about it and have good attention to detail. keep it up and experience will come. don't be afraid to experiment with tire pressures as well.
another thing i learned in the suspension tuning webinar was an air dryer. it essentially uses a filtration device to take humidity out of the compressed air you are putting into your tires. this was nothing new, just something i hadn't thought of yet. another option is nitrogen, but that is a little more inconvenient than $25 worth of parts for the in-line air driver that goes on your compressor. since you already have all the other neat gadgets, this might be something to look into if you haven't already. drain and fill your track tires with the dry air and it should help deal with some fluctuations in temps.

i highly suggest you email ross bentley (speedsecrets.com) and ask him for access to the recent "tune your car's handling" webinar. you won't be able to ask questions (it was live), but the six hours of content is well worth it.