The default "Loose" setup provided by the game is undrivable for 400 miles. The default "Tight" setup is too slow. You need a hybrid.
This setup is designed for the Sprint Cup Series cars within NASCAR '15 . It prioritizes a neutral handling balance that transitions to slight forward drive as the run progresses. It is suitable for racing the AI on Hard or Ace difficulty. nascar 15 charlotte setup
NASCAR '15 physics put a heavy emphasis on front grip. A 50% splitter helps the car turn into the corners. However, setting the spoiler too low (e.g., 35 degrees) will make the rear end slide out uncontrollably in traffic. 45 degrees is a safe, stable number that keeps the car planted on the long runs. The default "Loose" setup provided by the game
We have stiffened the Right Front (RF) spring significantly. This helps the car turn into the banking. The softer Left Rear (LR) spring helps the car rotate on the throttle exiting the corner. The ride heights are lowered to lower the center of gravity, improving stability, but kept high enough to avoid bottoming out on the bumps in Turns 3 and 4. This setup is designed for the Sprint Cup