Leave all the settings alone except turn the downforce all the way down. At Daytona, you should be in first place like this at turn 3 on lap one by drafting and staying low. After this, it's stay low, and watch your mirrors. When you think they are going to pass you going in to turn 1 or turn 3, they will slow down. But you HAVE to stay on the bottom of the track or they WILL wreck you.
Indy is easier. Get to the front by drafting and pass low. They brake early at every corner with plenty of passing opportunities, especially turn 1 on the very first lap, and turn 2 and 4 the rest of the time. They slow down for those corners and you should be able to take them at near full throttle.
