International Race Of Champions Series Racing

The premise sounds simple. Take 12 of the current fastest drivers throughout motorsports, give them race cars that are all equally prepared to race 100 miles without a pit stop, establish rules that allow no personal setup adjustments, qualifying, or car choice, and then drop the green flag and may the best man win. For 24 years, the True Value International Race of Champions, affectionately called IROC, has taken up this challenge of matching equal cars to extraordinary men, but it has certainly never been simple. Key to this unique competition has been making each car as identical in handling and speed as humanly possible. From the very first IROC cars, Porsche 911s, through Chevrolet Camaros, Dodge Chargers and Avengers, to the current Pontiac Firebirds, IROC Series president Jay Signore and his staff of 25 mechanics, fabricators, and engine wizards have patiently devised a proven method of race car construction that consistently offers no series driver a mechanical advantage.

This unique system of race car construction has had to evolve along with the series. The very first cars were each handbuilt with few, if any, matching parts, yet all made as identically as human hands could attempt. Still, with testing, practice, and race miles for the 12 IROC race cars, three practice cars, and four test cars equaling nearly 44.5 500-mile races a year, the exacting workload became overwhelming. "While very good race cars, the enormous time demands and costs of keeping these 12 unique 'one-offs' all equal, despite normal practice wear and tear, race event damage, and tight schedule restrictions, proved to be a monumental task," says Signore. "Over the years we have found processes to keep it simple by finding ways of working smarter, rather than harder. You could call it the 'IROC Way'."

Signore's "IROC Way" begins immediately after a car is chosen for the series. Chassis are constructed at Mike Laughlin's renowned racing fabrication shop in Simpsonville, South Carolina. Using NASCAR's Busch Grand National chassis as models, Laughlin creates the roll cage heart of the car with 600 lbs. of steel tubing, taking into consideration IROC's special rules allowing a 33-gallon fuel cell and unlimited ride height and spoilers. Then the completed chassis is delivered to IROC's 20,000 square-foot headquarters in Tinton Falls, New Jersey. Once there, brackets are established on the roll cage and a full-scale model in clay is formed around the chassis. This package is then delivered to the wind tunnel "soft," testing the engineers' ability to tailor the shape of the body to retain the car's recognizable showroom persona while also giving it stable aerodynamics in the draft and the ability to keep cool.

With aero numbers established and component placement tentatively set, the chassis is returned to the shop, placed on a surface plate, and as Signore says, "set up square to the world," that is, at ride height with no offset. A fiberglass body pulled from the clay template is then floated on the roll cage and attached. The mule is then returned to the wind tunnel for more data testing. Satisfied, the package is then track-tested. Here, inevitable tweaks follow as minor trackside changes are made to the body shape as the cooling system adapts to hot race track conditions, and moving suspension pieces establish body clearance throughout dynamic body roll ranges. Wheel openings are also checked with both the Daytona/Talladega tire and the Indianapolis/Michigan tire to ensure that no complications arise through the cars' 2-inch to 4-inch suspension travel.

Once this baseline package has been set the mule returns to the shop and becomes the tooling template for the new squad of IROC mounts. It is here that the "IROC Way" really shines. These cars are made to be virtually interchangeable, with templates producing identical body and component pieces. Each component's attachment points are made to match its share of the roll cage's more than 400 brackets to within 1/8-inch. Further, every component of each current IROC car will be an exact fit on any other current series car. This pays off in huge time and cost savings, as well as providing assurance that the cars are indeed identical. Assembled square, with specs matching the mule's, the 12 race cars and three test cars return to the track for race setup testing.Charged with testing the initial package, as well as setting up these actual race cars, is the enormously experienced team of NASCAR veterans Dave Marcis, Dick Trickle, Andy Hillenburg, and Jim Sauter. Their familiarity and trust with each other, from long hours of running inches apart at 180 mph, allow them to run drafting scenarios immediately. They are looking for consistency and comfort.

"The goal with these cars is not sheer speed," says Marcis. "We're looking to get these cars as equal as possible so that drivers from different types of racing organizations can drive these cars and be comfortable with them. "In IROC Series, we have sports car drivers, Indy car drivers, and stock car drivers from different NASCAR series, so we want the cars to be equal to the point where nobody has an advantage and everyone is confident in them." According to Signore, each test driver is encouraged to suggest areas to work on, though there have been times when the test drivers have differed widely on setup directions. "On these occasions, we let the drivers set up their individual cars as they believe they should be and then we just let them go out and race," says Signore. "The victor wins the argument." In final race trim, the finished products represent more than 600 man-hours of work, with an additional 125 hours required on each car after each race. A good deal of those between-race prep hours go into race drafting and wheel mark damage repairs. "We treat each event as if it were a 500 mile race," says Signore. Inside the engine compartment, Walter Smolinski's CNC-built engines produce 500hp at 6,800 rpm, with 435 lbs-ft at 5,600 rpm, with less than five horsepower or pounds of torque variance between engines.

With each race engine running less than 500 miles a sea son, they usually remain as the race motors for five years and then are rotated to the practice or test cars. Signore credits the rigid record keeping of his IROC group as a reason for the great dependability of the cars and their engines. "We demand zero defects, and with our thorough records, we can predict when each component is likely to fail," says Signore. "With our switch to the Oberg [now Holley] oil and fuel filtration system's mesh screens, for example, we can determine immediately whether a bit of metal is from a rocker, lifter, or bearing, and whether it's aluminum or steel."

The IROC team's efforts at equality also extend to shocks and springs. Each shock is dyno-tested and cataloged to avoid problems. Each spring is also team-measured to ensure an exact match, spring-to-spring. Signore also credits the great advancements that Goodyear has brought to race tire construction in the last 22 years as another reason the current IROC cars are much easier to sort, set up equally, and race than in earlier years. "Goodyear's tires provide a very predictable tuning tool for our suspensions," says Signore. " We find that one pound of air pressure consistently equals five pounds of spring. Their individual compounding for tracks is also a major asset to the setup."

For the sake of safety and comfort, the IROC team strives to have each race car set up to start off neutral and progress to slightly tight during the length of the race; never toward loose. To help drivers acclimatize themselves to the cars, each practice session is held at the same time of the day and for the same length of time as the actual race. Drivers can then become familiar with the car's handling as it would be on race day. Signore stresses that even still, there are many atmospheric factors that can influence the cars' handling during an IROC Series event, not to mention the drivers' individual styles. "If you send Dale Earnhardt out with a neutral car, he'll bring it back loose," says Signore. "Likewise, if Rusty Wallace goes out neutral, he'll bring it back tight. Little Al Unser will go out neutral and bring it back neutral, as did A.J. Foyt years back. With Richard Petty, he would always bring it back tight, tight, tight."

In the end, believes Signore, the drivers are all equally challenged to adapt to a neutral car setup that will allow them to race comfortably side-by-side. How much of a challenge is it really? "These days it is even more of a challenge for the NASCAR drivers than ever before," says Signore. "They all race well-engineered cars that suit their individual driving styles extremely well. Here they have to drive a car they can't adjust. So their adaptive process is just as difficult as the Indy car driver's...sort of the feeling you get sliding behind an unfamiliar rental car at night in the rain. To make the adaptation smoother, we have the test drivers on hand to help out with advice or to follow. We also have a full Pi Engineering data system on one test car to help them get up to speed quickly."

The results of this hard work speak for themselves. Close finishes, last lap passes, and tight series point standings are commonplace in IROC action. When the human element becomes the only variable, the performers command attention. The True Value IROC Series becomes the point where the top talent occupies center stage but not without those IROC machines, the supporting cast directing the spotlight.