Here's Herb Adams direct quote, "One reason we recommend larger, more effective stabilizer bars for Corvettes is the bars' ability to control a car's understeer characteristics. Standard Corvettes are produced at the factory with a great deal of understeer built into their suspensions.Anyone who has driven a Corvette hard into a corner has probably experienced understeer. The car "plows" or "pushes" through the corner. Regardless of the term used to describe the condition, the front tires must be pointed more into the turn to keep the car on its line (see diagram A). Oversteer is the opposite effect: the front tires are pointed outward, and the car is said to be "loose" or "hanging out" (as in diagram B). Neutral steer is the middle ground between oversteer and understeer. Both the front and rear tires are running at the same angle to the road. A Corvette set up for neutral steer will be faster in steady state cornering than one which over- or understeers because all four tires are sharing the cornering loads equally. By using the recommended stabilizer bars, your Corvette will become very close to the desired neutral steering attitude.
Factors such as the number of people in the car, road conditions, vehicle speed, and other variables can influence the handling characteristics of your car. Driving technique can compensate for these small changes if the car is close to the neutral state. In some special circumstances a slight degree of oversteer is beneficial. Certain autocross courses, for example, favor a car which oversteers somewhat. In general, though, you will probably be most comfortable in street driving conditions with a car set up to corner with a very slight amount of understeer.
It is necessary to control body roll on cars with independent suspensions because there is little anti-roll effect built in. Stabilizer bars control body roll by requiring the bar to be twisted if the body is to roll. Since larger diameter bars are harder to twist, they are more effective in limiting body roll. Stabilizer bars are used to control body roll because they have little effect on the up and down motions of the suspension. Stiffer springs can also be used to control body roll, but they also decrease the suspension's ability to absorb bumps so the ride quality is poorer.
Some of the reasons it is necessary to control body roll in cornering are for driver and passenger comfort, to limit the effects of roll steer, and to limit the loss of cornering power due to camber change. If a car rolls at too great an angle driving around a corner, like a Renault, the passengers feel like the car will tip over. Since the Corvette suspension has a considerable amount of roll-steer built in, this unwanted steering effect is reduced if body roll is reduced (roll steer is that part of the suspension geometry that causes the wheels to steer toward understeer as the body rolls.) GM always builds this into their cars on the premise that it makes them safe in spite of the driver's abilities. Performance minded drivers don't need much protection for themselves, so they don't need much roll steer.
The camber effects of body roll are caused by the fact that, as the body rolls, the tires roll with it. This causes the camber to increase on the outside tires, which reduces their cornering power, if body roll is minimized, the outside tires can remain perpendicular to the ground and deliver maximum cornering traction. The best way to limit body roll is to install bigger (and therefore stiffer] stabilizer bars. It is also an advantage to connect the stabilizer bars to the control arms with steel joints lo eliminate lost motion.
If a car, such as a Corvette, is equipped with both a front stabilizer bar and a rear stabilizer bar it is possible to control the amount of understeer and oversteer. When a larger rear stabilizer bar is used, the car will move toward the oversteer side of handling. If a large enough rear bar is used, the car will oversteer."
