In October of 1973, the American automotive magnate Roger Penske had 15 identical Porsche 911 Carrera 3.0 RSRs delivered directly from Zuffenhausen ahead of the inaugural International Race of Champions at Riverside in California. The series was devised to pit the finest drivers from a number of different disciplines against each other in identical cars at four events – three at Riverside and a ‘season’ finale at Daytona. 

All were televised over the winter of 1974–74, hence the Porsches’ vivid colours, designed to stand out on viewers’ new colour television sets. An extremely generous prize pot of 175,000 US dollars was also laid on, hence why the entry list was populated by a host of great names such as Emerson Fittipaldi, Denny Hulme, Richard Petty and Peter Revson. Despite this, it was the comparatively lesser-known Mark Donohue who became the first IROC champion after winning three of the four races. This impressive trio of victories included the curtain-closer at Daytona and netted him a princely 54,000 dollars. 

Incredibly, the very car in which Donohue won at Daytona to secure his IROC crown has just emerged for sale in the Classic Driver Market with the renowned UK-based Porsche sports and competition car specialist Maxted-Page Ltd. Few people realise that the IROC RSRs from 1973 were built specifically for Roger Penske, Porsche’s motorsport wizards back in Weissach applying a raft of special racing features to each from the forthcoming 1974 model. These included the extended ‘whale-tail’ spoiler to replace the ‘ducktail’, flared wheelarches and bumpers to accommodate wider Fuchs wheels, and an updated 3.0-litre twin-ignition flat-six kicking out a punchy 315HP. After all, this was an effective marketing tool for Porsche – not just a free-for-all deathmatch on the racetrack. 

Donohue wasn’t the first to race this chassis, number 9114600042, which was painted bright orange. Roger McCluskey, Denny Hulme and A. J. Foyt each had a go at pedalling it in the qualifying races at Riverside, but it was the gifted former Team Penske engineer-cum-driver Mark Donohue who got the job done in the final at Daytona. Since then, this ultra-significant Porsche 911, a veritable slice of American motorsport lore, has been in the hands of just three long-term owners, has been both well maintained and beautifully preserved, and benefits from a full engine rebuild carried out by Porsche Centre Melbourne in 2014. For the more serious Porschephiles seeking an automatic entry ticket to the world’s most prestigious road, race and static events, you needn’t look much further. 

Photos courtesy of Maxted-Page Ltd