You did not mention what kind of car so not sure if you already have a wing or can install a wing or adjust the angle of the wing to put more downforce on the car. Changing the things you mentioned can affect how the car 60 foots, Do you have the time to experiment ? You don't want the car to dance or be light on the tires at the top end.. putting downforce on the car would help your issue.
If your tires are old start there.... more info needed to help you... but downforce is needed if your car is light or dancing unless your track or the tires are the issue... or reduce the air from getting under the car.