How to Find Setup Information

Hi, my name is Nicole. My boyfriend races Sport Modifieds. We've been together almost a year now and this is my first summer racing with him. I know you have lots of letters and emails that you have to reply to and I feel bad asking for your help, but I don't know where else to go.

I don't know a lot about racing and have been trying to find books and stuff to help me learn the basics so I can understand things better. Sometimes when he is talking with his friends or other racers, I feel completely lost.

I want to understand the sport better and maybe someday be able to give him my advice on what I notice he is doing or what I think he should do differently with his setup. I can tell he wants me to as well. He tells me to read magazines (such as Circle Track) and learn that way, but I don't understand some of it.

OK, so what I'm asking is, what is your recommendation to someone who is just learning about the sport? Are there any books that would help me out? Anything you could tell me would be greatly appreciated. I just want to be able to show my support better.


—Nicole Kelly


I can't tell you how happy I was to get your email. Your involvement in your boyfriend's sport will certainly strengthen your relationship. It's so important for family and friends to get involved in racing. It makes it more fun for everyone.

You can go online to and read past articles about chassis design and setup. Look for the more basic content first and then move on to more technical discussions. Read back issues of CT that your team might have laying around.

Steve Smith Autosports also has been offering books and videos for many years that explain the systems and operation of every part of a race car. HP Books has stock car racing publications as well as Motorbooks International. Those are some of the more popular places to look to find information. Good luck with your racing and I hope you can be of use to your team.

Moment Center Chart Explanation

I found your article ("The Art of Moment Center Design," Dec. '11) interesting, but I didn't understand the chart for lateral placement of the moment center. Do the numbers represent distances left of center or right of center?

How about the height? Since the MC location is one of the factors controlling the amount of chassis roll, how do we determine if we are getting too much or too little roll?

Finally, when taking measurements for the MC location, do you use the centerline of the frame, or the midpoint between the hub faces?


—Al Jacobson


A negative number means the MC is left of centerline. Anything right of centerline is positive. Below ground is also a negative number and is never a good idea.

Height is important, but not nearly as much as lateral placement of the MC. We usually live with the heights of our MCs and work to design a lateral location that works for your type of racing.

With every race car, the chassis "feels" the MC location in relation to the tire contact patches. The interaction is between the MC and center of gravity and lateral forces are resisted by the tires at the contact patches. So, we usually define the centerline for purposes of MC location as the midway point between the two contract patches.