sierra4000 said:
a)"In a road course, transient response is king."
In any racing class where the range of driver talent and car quality present on the course at any one time is relatively small (think: F1, NASCAR, V8 Super TC, WRC, etc etc where all drivers are fast and all cars are reasonably good on the global scale) transients are what set cars apart.
For example- in F1. Every car's maximum lateral G level in perfect conditions, and given enough tuning, will be within a couple of percentage points of each other (if not tighter). What makes one car 'better' than another is the ability of the driver to transition from, for example, max acceleration (positive or negative) to max cornering force and back again in a way that is predictable. Some of this is directly related to driver skill, and some of this is a direct product of the quality of the engineering AND setup of the car. This is what Ciba is talking about when he mentions relating what the car is capable of to what the driver is capable of.
sierra4000 said:
ab)"You would probably be surprised, aghast and horrified if you were to find out what the "understeer" of some of the best race cars actually"
Notice the bit in Ciba's last paragraph- for a car in an oversteer state, steering gain rises with the SQUARE of speed. That means that at very high speeds, the car will have HUGE steering gain. This is very bad- one, it is potentially extremely hazardous to the driver's ability to survive the race and two, it usually makes it very difficult for the driver to approach and stay at the car's limit. The maximum speed/minimum lap time that the car is capable of may be the same, but it is more difficult for the human driver, regardless of skill, to take the car there and keep it there.
IN order to make a really, really fast car safe and driveable at high speed, and also to avoid having the driver think you're trying to kill them, it's usually prudent to set up a very fast car underneath the neutral steer line somewhere.
Understeer prone cars are also great for a crew chief with a driver that doesn't give great feedback. If the driver comes back saying 'the steering is getting light mid-corner, can we fix that??' but the lap times are fast- you're near the sweet spot.