As we build up to this year’s Rolex 24 at Daytona, RACER.com is pleased to bring you a series of excerpts from IMSA 1969-1989 by Mitch Bishop and Mark Raffauf. The soon-to-be-released inside history of IMSA’s first two decades is currently available for pre-order from Octane Press, and as a RACER.com reader, you can get $10 off by applying the discount code RACER19 at checkout. Click here for ordering information.

By the end of 1984, Porsche 962s were coming off the production line a Weissach in steady numbers and many of the Camel GT teams campaigning the outdated 935 and other early prototypes switched for the 1985 season. The effect was dramatic. Out of seventeen Camel GT races in 1985, Porsche 962s won all but one, a victory by Jaguar being the lone exception. Porsche 962 drivers finished first and second in the 1985 Camel GT championship standings, and six out of the top ten all drove 962s. It seemed the natural order of things had been reestablished—Porsche dominance was once again the law of the land.

The supremacy of the 962 started with the 1985 Rolex 24 Hours of Daytona, where the customer team of Preston Henn, using the now-friendly driver combination of A. J. Foyt and Bob Wollek, took the win with the aid of Al Unser Sr. and Thierry Boutsen. Foyt and Wollek went on to win the 12 Hours of Sebring in March, making them one of the few duos in history to take the endurance double in the same year.

If the 1985 season was all about Porsche, the undisputed king of the 962 was Al Holbert, who won his fourth Camel GT championship handily with nine overall wins. Derek Bell co- drove in the endurance events and piloted a second Holbert 962 solo in the shorter sprint races. Although the revitalized Group 44 Jaguar team scored an impressive one-two sweep at Road Atlanta in April and collected ten top five finishes that year, Haywood would go on to finish a distant third in the points standings. Holbert and Bell were simply too consistent, only failing to finish in the top ten twice.

Porsche’s six-cylinder turbocharged motor was so dominant that IMSA revised the technical rules at the end of the 1985 season, attempting to slow down the 962 and encourage the use of normally aspirated V8s in the series. In the meantime, other manufacturers introduced new GTP contenders in an effort to regain competitive position against Porsche.

Ford unveiled the lightning-quick Mustang Probe GTP, powered by a potent four-cylinder turbo and masterfully driven by Klaus Ludwig. Phil Conte brought two new V6 turbo Buick-powered March 85G chassis. They were also fast but not yet reliable. Producing in excess of 1,000bhp, the V6 turbos were driven by John Paul Jr., Bill Adam, and Whitney Ganz.

Rob Dyson joined the series at Lime Rock with a Porsche 962, where Drake Olsen won the event solo his first time out. Dyson Racing won again with Olsen and Bobby Rahal at the Road America Löwenbräu Classic five-hundred-miler, ironically in Budweiser colors. Olsen and Price Cobb added the inaugural Columbus Ford Dealers 500 street race to the Dyson team trophy collection later in the fall.

GM introduced its newest version of the GTP Corvette at Road America, which was powered by a single turbo V6 in a chassis based on the Lola T710. And BMW jumped back into the Camel GT Series at the end of the year with a new March 86G-based chassis.

By this time, IMSA was running separate races at many of the Camel GT weekends for the Camel Lights, GTO, and GTU categories. The GTO category was being dominated by production-bodied American muscle. In many cases, the bodywork shells were the only thing that even closely resembled the production version of the car; the GTO class had evolved into full tube-frame race cars. Ten manufacturers competed in GTO, but Ford took thirteen wins and proved hard to beat in both the endurance and sprint races.

John Jones crushed the GTO field in his Roush-prepared Mustang, winning seven races during the 1985 season. Lyn St. James spent the first part of the season in a Ford Cosworth- powered Argo prototype, then joined the Roush team later in the year as a full-time Ford factory driver. She scored two wins co-driving with Jones before a solo victory at Watkins Glen made her the first woman ever to win an IMSA GTO race outright. Wally Dallenbach finished third in the points with strong co-driving appearances for the Roush team. The other hot driver in GTO that year was Darrin Brassfield, who won five races in a Brooks Racing Ford Thunderbird.

Mazda’s Danny Smith and Roger Mandeville took the first non-Ford spot in the final GTO points standings and the only non-Ford race win at Charlotte. Dan Gurney’s All- American Racers (AAR) team brought new turbo engines for their Toyota Celicas and scored a number of strong finishes. Steve Millen took one win in the Dingman Brothers Valvoline Pontiac Firebird.

In GTU, a Mazda RX-7 driver won yet another champi- onship. Jack Baldwin scored five wins and was incredibly consistent with thirteen podiums in his Malibu Grand Prix– sponsored machine, run by Clayton Cunnigham’s Racing (CCR) outfit from southern California. The Mazdas were still tough, fast, and reliable—and there were lots of them.

The AAR team also competed in GTU with a nonturbo Toyota Celica piloted by Chris Cord, who finished in a solid second place in the championship with three wins and ten podiums. AAR had announced its arrival in style and many in the paddock wondered how long it would be before the team moved up. They didn’t have to wait long.

The introduction of the new Pontiac Fiero, powered by a 2.5-liter “Iron Duke” four-valve, four-cylinder engine was the shape of things to come. The attractive midengine car was a hit on and off of the track with Bob Earl taking six wins and Clay Young a single victory.