Great job!
Here are the three biggest areas I noticed that will help you get faster for next time:
1. Stay on the gas longer leading up to turn 1 and carry enough speed to force the car to the outside curbing on exit. Turn in location in turn 1 is good.
2. At the end of the back straight, the turn in is much too early, turning in later and quicker will allow you to get right on the gas after turn in and allow you to brake later on the straight.
3. At the exit of Thunder Valley turn in later there as well, it will point you further down the short straight to the carousel on the exit of the corner which will allow you to carry more speed through there. Then let the car drift a little further outside before turning in for the carousel to have a larger radius (different than a race line because you don't need to block a pass on the inside).
Also, which springs, swaybar settings and alignment settings do you have on the car right now? It seemed like a lot more understeer than I've ever had (except when I broke a rear endlink) and I wonder if you might need more spring, bar or a little more toe out in the rear to help it come around.