For 50 years, the International Motor Sports Association has been sanctioning, promoting, and nurturing sports-car racing in America and beyond. We’re celebrating IMSA’s golden anniversary with a series of stories looking at important eras, cars, drivers, and more.
Audi R10 TDI
In December 2005, Audi unveiled this prototype race car powered by a 5.5-liter twin-turbo diesel V-12. In its first season in 2006, the R10 won Sebring and Le Mans. Before Audi retired the car in 2009, it won 36 of the 48 races it competed in.
In 2010, in response to IndyCar’s call for an all-new car to debut in the 2012 season, Ben Bowlby, who worked for Chip Ganassi Racing, came up with the DeltaWing, showing it to stunned onlookers at the 2010 Chicago Auto Show. IndyCar turned down the wide-hipped, narrow-nosed DeltaWing, powered by a small four-cylinder engine. ALMS owner Don Panoz decided to fund its development, and the car was rushed through in time for the 2012 24 Hours of Le Mans. In 29 races, the DeltaWing never won, but it proved that a 300-hp challenger could indeed compete with models boasting more than double the power.
Toyota Eagle MkIII
Dan Gurney’s All American Racers crushed the IMSA GTP competition from 1991 to ’93 with the Eagle MkIII. Gurney oversaw in-house construction of the car, which was powered by a Toyota turbocharged four-cylinder. In 1992 the MkIII won nine of its 13 races, including the last seven in a row. In 1993 it won 10 of 11—and didn’t enter the 11th one. That was the end of the GTP class, doomed in part by the car’s domination. Overall the Toyota Eagle MkIII won 21 of 27 races.
The 962, designed by Norbert Singer, took everything Porsche had learned in prototype racing and rolled it into a car that was competitive from its introduction in 1984 until well into the 1990s, by then long in the exclusive hands of privateers. Racing and winning in the IMSA GT Championship, 962s also won the 24 Hours of Le Mans in 1986 and 1987.
Jim Hall, the taciturn Texan from Midland, built multiple Chaparral models. But the entire Chaparral sports-car line, from the original Chaparral 2A (the first Chaparrals were built by Troutman & Barnes in California—the ones built by Hall and partner Hap Sharp were called Chaparral 2s) to the wacky 2J, all reflected the innovation at work at Chaparral from 1963 to 1970. An aerodynamics genius, Hall used a large, cockpit-adjustable rear wing and progressed to the quickly outlawed 2J “sucker” car, which had two huge fans in the rear, powered by a separate two-cylinder engine to suck air from under the car, creating incredible downforce.
Archive photography courtesy: Revs Institute, Geoffrey Hewitt Collection, Karl Ludvigsen Collection, and Ken Breslauer Collection