Would you like a version specific to (which leans more arcade) or a hardcore sim like NR2003?
Before you touch a single spring rate, you must understand what Charlotte asks of the car.
The fastest way around Charlotte in NASCAR '15 involves running the bottom lane through turns 1 and 2. In turns 3 and 4, the car often feels tighter; you may need to drag the brakes slightly to point the nose toward the blue line before accelerating off the corner.
Since specific numerical setups are best viewed visually, users often recommend the following resources: