There is a known bug with the FC tires (http://forum.projectcarsgame.com/showthread.php?52810-KNOWN-ISSUE-Formula-C-FUBAR). After @Puffpirat mentioned the heating problem we did some research and found it.Great, I worked out a setup at the weekend because I won't have much time between now and Thursday and now i've got to do it all again. I don't see what was wrong with the original settings, you just need to work it out not change them with 2 days to go because it's a little tricky. So theres no point working on a setup before Wednesdays in future just in case it all changes then.
I am also pretty sure that ur setup won't be crap in the July conditions.