Even with sophisticated test...
Even with sophisticated test rigs, such as this K&C rig being used by Morse Measurements in Salisbury, North Carolina, racers still must rely on trial and error for the most part, but there is a better way.
We first presented this material in CIRCLE TRACK in early 2003. Since that time we have made reference to bits and pieces of it to illustrate other discussions. The technology presented here represents the greatest leap forward in basic automotive dynamics technology in the last 20 years or so. The basic principles that represent the foundation of this technology were developed some 60 years ago, and what you will read here is a refinement of much of what came later.
When most of us think of the development of racecar dynamics, we may immediately think of the major innovations coming from Indy car racing and/or Formula One. That is a natural conclusion given that they appear to be more sophisticated in design, but the true story is much different. In this particular field of science, stock car racing today is at the head of the class.
Roll centers, or moment centers...
Roll centers, or moment centers in reality, and centers of gravity, centrifugal forces, and gravity all have a role to play in determining the desire of the front end of the racecar. We have finally determined the true dynamic effect of these components.
The historical record of the evolution of the knowledge of vehicle dynamics runs directly parallel to the development of the passenger cars and trucks for several understandable reasons. First and foremost, the big automakers had the funds to finance the extensive and expensive research. Also, the need existed to develop better suspension systems for ride comfort as well as drivability. Along with these two "driving" forces also existed the element of competition among automakers which led to the development of more advanced street cars.
The "win on Sunday, sell on Monday" attitude was not restricted to American automakers. Companies such as Ferrari, BMW, Toyota, and Honda, as well as others hold the same to be true. Without racing, the companies would not have had a venue to show the superior quality and the advanced mechanical systems they developed. Consumers relate to and buy winning auto maker's cars.
The Ferrari cars have dominated...
The Ferrari cars have dominated the past few F1 seasons with numerous wins and Firsts in championship points. Observers of the series noted throughout the past five years that the sleek red Italian cars just flat out handled better than their competition and the McLaren cars are almost equal. So, why is it that the Renault and Honda teams (seventh and nineth in constructor's points to date) cannot match the performance of Ferrari and McLaren in 2008? Could it be they cannot find the dynamic balance? When watching the races and hearing the drivers, handling is a concern. Courtesy of IMS Photo
Stock car racing has always been thought of as the "soap box derby" in all of auto racing. In leading books on the subject of racecar dynamics, stock cars are often referred to as a "particular case" and often referenced by their unpredictable nature associated with handling. It is fairly easy to adjust the handling on an open wheel formula car with wings in the front and rear. A little more downforce at one end will effectively cure a tight (under-steer as it is called in those circles) or loose (over-steer) condition. With the stock car, we do not have such options. The limitations and restrictions imposed by the "stock" chassis' confuse many automotive engineers.
From the 1940s up until the early '90s, no one had defined what comprised a perfect setup for a stock car. For that matter, no one had learned what any racecar wanted for its perfect setup. Setup in all series had largely been developed by trial and error methods, even with the most advanced forms of auto racing.
To better understand and prove why this is true, we need only to take a look at and listen to all of the teams in the top racing series today. In descending order related to how much money is spent for each type of race team we quickly recognize the top contenders. Formula One is far and away number one, NASCAR Sprint Cup is now second, Indy Car racing is third, and U.S. road racing such as the Grand Am DPs and American Le Man Series are fourth and fifth.
A casual observer would, based on the media hype and subterfuge presented, assume that the technology exists that would accurately predict the handling characteristics of the vehicles in each of these top series. But as we listen to the drivers and crews, we find out it does not.