Ok, take one of the most disappointing cars for me, the 63 Stingray. The tire model for this car causes the rear to lose grip at mid exit. Stretching the gears and shifting early according to the graph helps, but it's still present. Adding power parts and then lowering using limiter, allows you to get a better power band according to the graph, more power faster and longer. However, exit control, getting the power from the tires to the tarmac is now made significantly worse. Simple fix is to use gripper tires, but in a SH event, that's not possible.
Lower pp cars are less likely to be affected compared to higher powered, high pp cars.
That help?