1974 Porsche Carrera IROC RSR

The International Race of Champions (or IROC) was created by Les Richter, Roger Penske, and Mike Phelps in 1973. It was designed to place the world's best-racing drivers in identical cars to compete against each other over several rounds at US venues. The equal playing field allowed the best, cleverest, and bravest drivers to prevail.

Penske contracted 12 of the top drivers from the four main branches of racing: Peter Revson, Emerson Fittipaldi, and Denis Hulme from Formula 1; Mark Donohue and George Follmer from SCCA; Bobby Unser, A.J. Foyt, Gordon Johncock, and Roger McCluskey from USAC; and Richard Petty, Bobby Allison, and David Pearson from NASCAR.

Penske spoke with Mark Donohue about his choice for a reliable and consistent racing car - Donohue suggested that Penske contact the Porsche factory and order a run of the latest racing 911s. Penske followed his advice and Porsche built 15 examples of the 911 Carrera RSR for the IROC series. They were built to identical specifications and all painted in bright colors with black Porsche script on the rockers for maximum impact on television.

The inaugural IROC season was held at two tracks over two weekends in 1973 and 1974. The first three races were held on October 27 and 28 at Riverside International Raceway. The final race was at the Daytona International Speedway road course on February 14th of 1974. Donohue finished in first place, followed by Peter Revson, then Bobby Unser in 3rd, David Pearson in 4th, and George Follmer in 5th. The remaining twelve finishers were in this order: A.J. Foyt, Emerson Fittipaldi, Denis Hulme, Bobby Allison, Richard Petty, Gordon Johncock, and Roger McCluskey.

The 1974 Porsche 911 Carrera 3.0 RSR IROC was powered by a 2,994cc SOHC Type 911/74 flat 6-cylinder engine with Bosch mechanical fuel injection and delivering 315 horsepower at 8,000 RPM. It was paired with a five-speed manual transaxle and four-wheel ventilated and drilled disc brakes provided the stopping power. The suspension was independent with torsion bars and shock absorbers.

by Daniel Vaughan | Apr 2019