Casey Mears explains what...
Casey Mears explains what the car is doing, or not doing as the case may be, to crew chief Alan Gustafson. I think what all race teams desire is that perfect balance that will make the car fast and be fast for long periods of time. How often have we seen someone sprint to the front only to drift back several laps later? In Sprint Cup racing, it's still largely trial and error, or what I like to call "reactive engineering." Courtesy of NASCAR
The Ferrari cars have mostly dominated F1 since the year 2002 because they consistently out-handled the competition. At times they were admittedly under-powered, but still turned faster lap times, and that comes from a better handling package. Even new McLaren driver Lewis Hamilton will tell you that he can only drive the car as fast as it wants to go. Fernando Alonso is known as a very good development driver, but not even he can get the once powerful Renault cars up to speed to compete with McLaren and Ferrari, whose cars flat out-handle the others.
It is the same for American based formula cars and Sprint Cup teams. How many times have you heard a SC driver complain of a tight or loose or unpredictable car? It's hit or miss, and whether you're Lewis Hamilton or Tony Stewart, at each race you hope the crew and engineers have guessed correctly.
What has been refined in most top racing series is the hit and mostly miss art of trial and error. Advanced measuring systems are in use today that not only record movements, pressures, and temperatures but also the forces exerted on components. These systems have become useful and necessary tools of the modern day chassis developer. As the teams compile and study all of this information, the fact still remains that they react to, and do not predict, the handling nature of their cars. I call this "reactive engineering" as opposed to "predictive."
Harry Hyde (left) was a crew...
Harry Hyde (left) was a crew chief that worked with his own calculations trying to balance his cars. He had his own method worked out and found much success in former Winston Cup racing. He won a lot of races with Bobby Isaac (right), Sam McQuagg, Tim Richmond, and others. Photo by Ken R. Noffsinger
The big news is that technology has evolved and the ability to predict the handling characteristics of your car is available. This information did not come out of any of the major automakers engineering departments nor F1 or Indycar racing. It came from stock car racing and has many times proven itself for over 10 years now.
Developing and refining this technology was a fairly long process and involved many persons, but the "who" is not as important as the "how" and "why?" The answers to those questions begin with a short study of the history of the development of the automobile.
Long before the car, we had horses and wagons. Transportation technology took a quantum leap with the invention of locomotive trains. The first steam powered locomotive was built in 1804 in Wales and was used in mining operations. As the design of trains advanced towards the late 1800s, so did our understanding of powered vehicles. It was inevitable that the automobile would become a vital mode of transportation.
As the auto became more popular, its chassis design became more advanced. The 1903 Ford Model A, the first production automobile, was built much like wagons with leaf spring suspensions similar to the stage coaches of the early days. Power was transferred to the rear wheels via a chain and sprockets. The 1909 Model T incorporated a transmission and drive shaft for the first time and that system is still in use today.
The typical stock car has...
The typical stock car has a front suspension system using double A-arms. These arms are attached to a spindle and the controlling dynamic point is commonly called the roll center although the car rarely rolls around this point. McPherson Strut front suspensions are being used more and more in stock car racing and that system also has a roll center point, similar to the double A-arm system.
The front suspension of that car used one piece spindles attached to the ends of a transverse (sideways to the centerline) leaf spring and used a drag link steering system, similar to the ones used today in many American production and racing stock cars.
Eventually the automakers developed the double A-arm front suspension system using coil springs. That system is the primary system used in stock car racing today.
So, the vehicle we are trying to predict the handling of has a stiff chassis (further strengthened by a roll cage and supports at the front and rear) with a double A-arm, coil spring front suspension, and a solid axle rear suspension with either coil or leaf springs.
The front and rear suspension systems in stock cars are very different from one another both in appearance and in the way they react to the cornering forces that they encounter. Therefore, we must necessarily treat each system independently and try to determine what each one wants to do as the car turns. If we can predict exactly what each desired to do, then we can match the "desires" of both to help create a truly balanced setup.