1979 Porsche 911 Turbo

Much of the development of Porsche's road-going 911 Turbo had resulted from the factory's racing program. At the time, the FIA Group 4 homologation rules required 400 road cars to be constructed, spurring the development of 'Project 930' - the 911/930 Turbo. Porsche's experience with turbocharged racing cars included the 917/10 and 917/30 'Turbo Panzer' Penske/Donohue Can-Am cars.

Production of the 911 Turbo began in April of 1975 and employed a KKK turbocharger to the 3.0-liter Carrera RSR engine. The road-going version developed 260 horsepower resulting in a top speed of 155 mph. Along with power, the 911 Turbo was also the best-equipped 911. Distinct styling elements included flared wheel arches and 'tea tray' rear spoiler previously seen on the Carrera model. The 'whale tail' spoiler helped keep the car grounded at high speeds and vented more air to the engine. The wider wheel arches allowed for wider rear wheels with upgraded tires, increasing the car's with and grip, making it more stable at speed. The interior featured leather upholstery, air conditioning, and electric windows.

To cope with the increased output from the engine, the suspension was revised, the brakes grew larger, and a stronger gearbox was fitted. while the 'lower trim' Carrera model used a five-speed gearbox, the Turbo used a four-speed manual.

The 'Turbo' was introduced at the Paris Auto Show in October of 1974 with sales beginning in the spring of 1975. Exportation to the United States began in 1976.

Porsche produced the required 400 examples of the 930 Turbo with the allotted twenty-four-month period and gained homologation for the racing variant - the 934 - on December 6th of 1975. The Porsche 934 was the company's Group 4 entry and the 935 was developed for Group 5 competition.

The engine's displacement size grew to 3.3-liters (3299cc) in 1978, gaining an intercooler in the process. The cooling of the pressurized air charge by the intercooler was helpful in increase output to 300 bhp at 5,500 RPM and torque to 304 lb-ft at 4,000 RPM. Top speed increased to 160 mph. Design changes were minimal, however, the rear 'whale tail' (now called the 'tea tray') spoiler was re-profiled and raised slightly to accommodate the intercooler. Mechanical improvements included new anti-roll bars, larger diameter rear torsion bars, and firmer shock absorbers. The brakes from the 917 race car now provided the stopping power.

Between 1979 and 1984, the 911 Turbo was unable to be imported into the United States due to strict emission regulations. It did, however, return in 1985 when equipped with upgraded Motronic engine management systems. Targa and Cabriolet versions were also introduced.

The careful and relentless development of the 930 resulted in a sound base for racing vehicles and led to the highly successful 934 and 935 racing cars which dominated all the great endurance races for years.

by Daniel Vaughan | Jul 2021