Photo by Brian Cleary, Grand Am Racing
Many well-known circle track drivers have tasted the wine-and-cheese circuit in all types of road racing cars. Tony Stewart drove a Daytona Prototype in the 2005 Rolex 24 at Daytona, and was leading with one hour to go when a part failed.
Ever since the Winston Cup boys started racing on road courses such as Riverside, California, and Watkins Glen, New York, some weekend circle track racers have desired to combine turning left with turning right. There is something intriguing and attractive about having 10 or 12 turns, all different, instead of basically two. So, we now have venues where a circle track racer can compete on road courses, sometimes with the same car.
Because vintage racing participation is growing and because so many of the Nextel Cup drivers as well as successful touring drivers are opting to drive on road courses in various series, we decided to address the setups for those cars as opposed to just turning left.
Ted Christopher, Northeast Modified champion, is shown here talking to the engineers durin
There are more than a few recognizable names who have driven in the 24 Hours of Daytona and other road races. These include Nextel Cup drivers Bobby and Terry Labonte, Kyle Petty, Tony Stewart, Rusty Wallace, Dale Earnhardt Jr. and Sr., and Kevin Harvick. More recently, Northeast Modified champion Ted Christopher has been added to the list. T.C. drove a Daytona Prototype for Doran Racing in the Grand Am Rolex 24 at Daytona race this year. The 2004 NASCAR Atlantic Regional Late Model Stock champion Steve Blackburn drove a Pontiac GTO in the Grand Am Cup division, a race that was run just prior to the 24-hour race also this year.
The most popular forms of stock car road racing today are the various vintage racing formats that allow older Busch and Winston/Nextel Cup cars to compete. The V8SCRRS, SARRC, and HSCRS are examples of vintage racing organizations that allow current and former circle track racers to compete. Even the Canadian CASCAR Super Series runs on the Mosport road course for one of its scheduled events. The popular Crown Royal IROC series will, for the first time, hold a road racing event at Daytona on June 29, 2006. As you might recall, that series invites championship racers from many different divisions to race together in a series of races, mostly on circle tracks.
Peculiarities of a Road Racing Stock CarIf we were to convert a circle track car into a road racing car, there are several areas of concern that must be addressed. Setting up a stock car for circle track racing is, in a number of ways, much easier than for road racing.
The front and rear suspension on this Spirit of Daytona Prototype is the double A-arm type
For circle track racing, we can set opposite cambers for the front and rear tires. We can adjust rear steer, crossweight (bite/wedge), and geometry to suit just turning left. For road racing, many of these same settings are a compromise, and that complicates things.
The issues and differences we need to address include: 1) front and rear camber settings, 2) front and rear geometry, 3) weight distribution, and 4) front and rear stagger (or lack thereof). Let's examine each particular area of setup and define how we approach them from a road racing perspective.
Since we will be turning left and right on road courses, we need to set negative camber (top of the tire leaning in toward the center of the car) in all of the wheels, front and rear. That means, of course, that the inside tires in each turn will be off camber and provide a lot less footprint than the outside tires, which have the proper negative camber.
This car has a coilover spring and shock combo, just like a Late Model that is connected t
The front tires are more prone to camber deficiencies than the rear tires, so we have a contributing factor in the car being tight, or understeering as the roadies call it. Therefore, the outside tire will be working harder to turn the car. Both front tires will probably need more camber than we would put in the car for a flat circle track, where the inside wheel is in positive camber and helping more so to turn the car.
A typical circle track car has positive left-front (LF) camber and negative right-front (RF) camber. In our conversion to road racing, we need to change the LF suspension to attain negative camber. We also need to make sure the control arms are the same length.
The effect is the same with the rear tires, but not to the same degree. We need to put more negative camber in those wheels from settings we know for circle track racing, because the outside tire is working harder.
The tire temperatures need to be read and set a little differently than normal oval racing requires, too. If the inside half of the inside tire is all that is working inside the turn, then that portion of the tire will heat up more and retain the heat when we have entered the pits and taken tire temperatures. Because we want to set cambers to benefit the footprint while the particular tire is acting as the outside tire, we should set the cambers so that we always read hot on the inside of each tire by 15 to 20 degrees.