An excess of Ackermann steering...
An excess of Ackermann steering effect would not be noticeable on the closest car because only one front tire is touching the track. The back car would definitely be affected as both front tires are firmly on the ground.
The articles I most enjoy writing are the ones that make the most performance difference. I have included Ackermann information in my general alignment articles in the past and have dedicated whole ones to the Ackermann effect. You might also have noticed that I will repeat myself every two years or so, or sooner if the need arises. This is one of those times.
The reason I tend to harp on certain setup phenomenon is because of several things including the fact that we have new racers coming into the sport all the time, new readership regardless of the time spent in racing, and because some of us need reminding from time to time. You might have gotten the message, but you may move to another team and it might not have gotten the message. It's helpful in your argument for certain processes to refer to a recent article, any article, in Circle Track.
Ackermann is important because it can ruin an otherwise great setup. Knowledge of it is important for all types of auto racing, not just circle track. We have readers from all walks of racing life. We have confirmed reports of our magazine ending up in the bathrooms of Sprint Cup teams too numerous to mention in the limited space we have here. Sprint Cars, dirt cars, asphalt Late Models, SCCA cars, Formula cars, IndyCars, and Formula 1 cars all must be concerned with the effect of Ackermann, and they certainly are.
In this day and age, for both the dirt racers and the asphalt teams, modern setups dictate a closer look at many areas of chassis geometry and alignment. If we prioritize the various areas of concern, Ackermann would rank right up there near the top. More importantly now, modern setup trends in both dirt and asphalt racing dictate that we need to take a closer look at our Ackermann situation.
Years ago it was fairly common to see a dirt car with the left front tire up off the track in the turns or see tire temperatures on an asphalt car's left front tire that were the coolest of the four. These were the result of unbalanced setups where the rear suspension desired to roll much more than the front suspension. In those days, greater amounts of Ackermann could be desirable, or at least less harmful to our handling. If the LF tire is off the racing surface it can do no harm.
The History of Ackermann
Effect Ackermann effect is a mechanical phenomenon that is associated with an automobile's steering system. A steering design that incorporates Ackermann causes the inside (closest to the radius of the turn) wheel to turn a greater amount than the outside wheel. We do need a slight difference in steering angle between the front tires because the inside wheel runs on a smaller circle or arc than the outside wheel. The key word here is "slight."
Ackermann effect is named after the man who did extensive research and development on the subject. Early on in basic automotive design and development, engineers discovered the need to design a system for steering a production car so that each wheel tracked correctly when the car was negotiating a turn. The ideal system would compensate for large radius turns as well as for tight, "turn right at the stop sign," type of smaller radii turns.
An early story offers that many of the very first owners of automobiles were concerned about tearing up their circular gravel driveways and the Ackermann designed into the steering helped keep the wheels tracking correctly and reduced the primary cause of rutting in the driveways. Modern racing stock cars have little in common with production cars, so we need to readdress the issue of Ackermann.
Do We Need Ackermann in Our Race Cars? There have been many opinions about the use of Ackermann in our race cars and whether it really helps. Numerous older books and articles on the subject extol the benefits of Ackermann to help the car to turn. Were these articles correct about this subject? The answer is Yes and No. Here's why.