The True Value Firebird International Race of Champions, a unique concept matching 12 drivers from various forms of motor racing in identically prepared cars, can't go back to its roots because there is no more Riverside International Raceway.
It was there, on the twisting road course just north of March Air Force Base, that the first IROC was run on Oct. 27, 1973. The late Mark Donohue was a start-to-finish winner and the cars were Porsche Carreras, riding on Goodyear tires.
This year, IROC will return as close as it can to its origin. The new California Speedway is only 20 miles from Riverside, and the people in charge for the 21st running are the same as they were for the inaugural--Les Richter, Jay Signore and Penske Racing.
The 12 cars this time will be 350-cubic-inch Pontiac Firebird Trans Ams equipped with Goodyear Eagle radial tires and prepared by Signore at IROC headquarters in Tinton Falls, N.J.
"The only difference in the cars will be their color and car number," Signore said. "Every part is the same. Each car is built exactly the same way. When the cars go on the track, they are as equal as it is humanly possible to make them."
The only changes drivers can make are adjustments to the position of the seat, steering wheel and pedals. Cars are assigned by a blind draw just before each of the four events.
On the other hand, the drivers are as different as the cars are similar.
From the high banks of NASCAR come Mark Martin, the IROC points leader after two events; Jeff Gordon, the precocious Daytona 500 winner; Terry Labonte, the Winston Cup champion; Dale Earnhardt, twice an IROC champion and seven times a Winston Cup champion; Dale Jarrett, a two-time Daytona 500 winner; Darrell Waltrip, a 25-year Winston Cup veteran in his eighth IROC; and Randy LaJoie, the Busch Grand National champion.
From CART there will be Al Unser Jr., a two-time Indianapolis 500 winner, two-time CART champion and two-time IROC champion; Jimmy Vasser, current CART champion, and Alex Zanardi, winner of the Long Beach Grand Prix--the only foreign driver in the race to keep its "International" flavor.
Rounding out the field are Tom Kendall, a three-time winner of the Sports Car Club of America's Trans-Am sedan series; and Robby Gordon, SCORE International champion in the Trophy Truck off-road series.
Unser, Vasser and Zanardi will be traveling to Fontana via private jet after qualifying for a CART race in Portland, Ore., earlier in the day.
When IROC was proposed, the idea was to determine who was the best driver in the world, including champions from Indy cars, Winston Cup stock cars, Formula One and world sports car competition.
The first lineup included sports car drivers Donohue and Peter Revson, both also sometime Indy car drivers; Indy car champions A.J. Foyt and Bobby Unser, NASCAR veterans Richard Petty, David Pearson and Bobby Allison and Formula One champions Emerson Fittipaldi and Denis Hulme.
But all four of the races were on road courses, and after Donohue won three of them, oval races became a part of the series.
Donohue's final IROC win, on Daytona's road course in February, was the last of his career. He had retired earlier as an active driver, only to return to competition later that year. He was killed the following season during an accident in practice for a Formula One race.
"We don't know if IROC determines who the best driver in the world is, but we sure go a long way toward that goal," Richter says. "IROC does prove that some drivers have more skill than others, regardless of their specialty or background in racing."
Some, such as Kendall, relish the opportunity to prove themselves against other champions.
"IROC is fun because the pressures involved are so different," said Kendall, who has won all five Trans-Am races this year. "They are totally self-induced. You have that in other racing, but also extra pressures from long-term contracts and sponsor relationships and sanctioning bodies. In IROC, it is pure enjoyment, pure fun.
"In Trans-Am, I've done just about everything you can do. In IROC, second is my best finish, and I want to try to do something with this and I get really fired up for these races.
"I was tremendously excited to get invited to IROC because of what it means about your status in the racing community. But until I win one, I feel like I can't rest."
Kendall, in his fifth IROC, is ninth in points after a fifth-place finish at Daytona and ninth at Charlotte. A graduate of UCLA who lives in Santa Monica, Kendall says of his role in the series, "It's almost like you had a bit part in a movie. Everyone asks, 'What's it like? What's he really like in person? What's it like to race with Dale Earnhardt?' That's what the people I race with on a regular basis want to know.
"I think if you asked most people who have followed racing for a long time and asked them about IROC, they would think Riverside. That's going back to when I was pretty young, but that's what I think of.
"I can still see the guys going through the 'esses' with the dirt flying."
Sixteen IROC races were run at Riverside, more than any other track except Michigan Speedway, which has had 22 and will be the site of the 1997 finale on July 27.
Only three of this year's field--Unser, Labonte and Earnhardt--drove in the last IROC at Riverside, on June 11, 1988. Scott Pruett was the winner.
"The first time I'll see the California track is in an IROC car," said Unser, IROC's all-time leader with 11 victories, including this year's opener at Daytona. "I know it's supposed to be a lot like Michigan, which I think means we'll have a great race and put on a great show for the fans."
Dave Marcis, a veteran Winston Cup competitor and IROC test driver, drove the Firebirds at California Speedway last month and confirmed Unser's appraisal of the track.
"It's a very similar layout to Michigan," Marcis said. "The surface is very smooth, but the set-up will be very similar to what we run at Michigan. We found that, as we were working the corners, we will see three-abreast racing."
If Michigan is the criterion, it could favor Unser. He has four IROC victories there. Martin, Earnhardt and Labonte each have one.
Unser is second in points, five behind Martin, at the halfway point this year. He won at Daytona, but Martin, the defending series champion, has won three of the last four races, most recently last month at Charlotte.
Martin, Unser and Earnhardt are all trying to become the first three-time champion. Martin won in 1994 and '96, Unser in 1986 and '88 and Earnhardt in 1990 and '95.
There is no qualifying in IROC. At the first race, drivers draw for starting positions.
For the Fontana race, standings after the first two events determined the starting order, with Martin, the leader, starting last and Zanardi, the driver with the fewest points, on the pole.