1972 Porsche 911 ST

The Porsche 911 Rs and T/Rs had been very successful in road rally competition in the late 1960s. For the 1970 season, Porsche offered the ST. Around 36 examples were built and each was tailored to customer's request. Thinner gauge steel was used for the floorpan and roof which reduced the overall weight of the vehicle. Depending on the customers' requests and budget, plexiglass windows and aluminum doors could also be fitted. A variety of fuel tank sizes were also available. Following newly introduced racing regulations, Porsche widened the track which allowed for wider wheels and tires.

Power was supplied by a modified version of the road-going car's 2.2-liter flat-six. Rules stated only the bore was allowed to be increased to a maximum of 2.5 liters. Initially, Porsche increased displacement to 2.3 liters. Additional modifications included a pair of triple-choke Weber carburetors and high-compression pistons, which helped increase horsepower to 230 bhp. Some of the cars left the factory with the standard 911 gearbox, while others were outfitted with the Type 915, five-speed unit.

Porsche retained three 911 ST cars for 1970 as factory works vehicles. An additional fifteen examples were built for privateers.

The Porsche 911 ST earned the company the International Rally Championship in 1970. Privateers and the Porsche factory raced the 911 ST successfully in a variety of events, with wins in 1970 at the Tour de France Automobile, Monte Carlo Rally, and the 36 Hours of Nürburgring, among other victories. At the 24 Hours of LeMans, the 911 ST dominated the GT class.

For 1971, the engine displacement size grew from 2.3 to 2.4 liters. Horsepower rose to around 250 bhp. The factory cars were given an experimental Type 911/21 engine that produced around 260 horsepower. Additional weight-saving measures were found, reducing the weight to 800 kg. Using titanium and additional glassfiber components, the weight was lowered again to 789kg. Around 12 examples were produced.

The final iteration of the 911 ST saw its displacement size increase even further, to 2.5 liters.

by Daniel Vaughan | Apr 2019