Thirty Years of the Porsche 911 Turbo

Press Release

Engine Chronology

Immense Power: from 260 to 450 bhp

M 930/50 turbo engine – this was the code name of the power unit featured in the very first 911 Turbo launched at the 1974 Paris Motor Show. Like all other 911 Turbo engines up to 1998, it was based on Porsche's classic six-cylinder normal-aspiration power unit. The foundation only changed in the year 2000, when the engine of the Porsche 911 GT1, the winner of the 1998 24 Hours of Le Mans, became the basis for the 911 Turbo power unit. Indeed, this racing engine also has a second “child": the normal-aspiration power unit of the 911 GT3 and GT3 RS.

The first generation: 260 bhp from three litres capacity

The M 930/50 developed maximum output of 260 bhp at 5500 rpm. The first 911 Turbo engine for the road was derived from the power unit of the 911 Carrera RS 3.0 still in production at the time. The compression ratio was 6.5:1, a higher ratio being neither necessary nor desirable, given the maximum charge pressure of 0.8 bar. The extra weight of the turbocharging system was 25 kg, the engine itself weighing 207 kg or 456 lb. Maximum torque of 343 Newton-metres (253 lb-ft) was available throughout a wide speed range, with the engine's starting characteristics, idle and warm-up behaviour being just as simple and straightforward as on all other Porsches. While this may be regarded as quite normal today, such issues were of great significance at the time when introducing a new technology. The 3.0-litre turbocharged engine was built from September 1974 – August 1977.

300 bhp from larger engine capacity and intercooling

Referred to within the Company as the M930/60, the 3.3-litre power unit built as of the 1978 model year developed maximum output of 300 bhp, again at 5500 rpm. Some of the extra power came from larger engine capacity, another, at least equally important factor being the introduction of an intercooler reducing the temperature of the compressed air by approximately 50o C before the engine was able to flow into the combustion chambers. The compression ratio, in turn, was increased from 6.5:1 to 7.0:1, improving both fuel consumption and, as a result, the car's high standard of economy in general. And last but not least, various design changes were made on other parts of the engine such as the crankcase and crankshaft.

The new Turbo entering the market in 1991 was once again called the 911 Turbo 3.3. The obvious objective from the start in introducing this new model was to have even more power and performance than on the former Turbo, since the 911 Carrera 2 launched in 1990 now came quite close in terms of performance to the former Turbo 3.3. The code name of the updated 911 Turbo power unit was M 930/68, a larger turbocharger and intercooler helping to develop maximum output of 320 bhp at 5750 rpm. This power unit was replaced by an even larger 3.6-litre engine after not quite two years, output being raised to an even higher 360 bhp at 5500 rpm. The compression ratio was 7.5:1, charge pressure was increased to 0.92 bar. And in test drives with the new 911 Turbo 3.6, auto motor und sport, Germany's leading car magazine, reached a top speed of 289 km/h or 179 mph.

Two turbochargers closing the “turbo gap"

At the 1995 Geneva Motor Show Porsche presented an all-new 911 Turbo based this time on the 993 model series. The underlying engine, as in the past, was Porsche's normal-aspiration power unit, in this case the M 64/05. But now, for the first time, the engine was boosted not by one large, but rather by two small turbochargers, each connected to one row of cylinders. The compression ratio, in turn, was raised to 8.0:1. Benefitting from smaller mass inertia, the two small turbochargers responded more spontaneously than the larger turbine used so far, making the “turbo gap" a thing of the past. Two completely new highlights were the exhaust system and electronic engine management referred to as “Motronic". Running even more economically on even less fuel, this new Porsche Turbo now featuring four-wheel drive and a six-speed gearbox impressively provided a level of performance hardly seen before at anywhere but the race track: acceleration from 0 – 100 km/h in 4.3 seconds, and a top speed of 293 km/h or 182 mph.

The latest generation: 450 bhp for a top speed of more than 300 km/h

The 996-series 911 Turbo based on the 911 Carrera 4 was launched in the 2001 model year. Water-cooled and featuring four valves per cylinder, the 3.6-litre power unit referred to within the Company as the M96/70 comes from the 911 GT1 built in 1998, the racing car which helped Porsche clinch a one-two victory in the 24 Hours of Le Mans in 1998. Among the special features of this outstanding engine, the crankcase is split vertically and the cylinder heads are made of a high temperature-resistant light alloy. Oil is supplied by classic dry sump lubrication.

All 911 power units have featured water cooling ever since the 1999 model year. The current 911 Turbo develops maximum output of 420 bhp (309 kW) at 6000 rpm, making this the first model to break the 300-km/h (186 mph) mark, with a top speed of precisely 305 km/h or 189 mph. Yet another, at least equally impressive feature, is that fuel consumption is down from the already economical former model by another 18 per cent, despite this supreme power and performance. And exhaust emissions have decreased by an average of 13 per cent. This results primarily from Porsche's VarioCam Plus valve timing and management system providing variable valve timing not only for sporting and dynamic performance, but also for efficient emission control and stable idle speeds.

This year Porsche has quite literally boosted the car's output yet again, introducing the new Turbo S available in both Coupé and Cabriolet guise. Maximum output is now 331 kW (450 bhp) at 5700 rpm, that is 30 bhp more than the 911 Turbo. Using larger turbochargers, further refining the intercooler, and revising the engine electronics, Porsche has given the 911 Turbo S maximum torque of no less than 620 Newton-metres or 457 lb-ft consistently maintained between 3500 and 4500 rpm. Fitted with a manual gearbox, the Coupé accelerates to 100 km/h in 4.2 seconds (Cabriolet: 4.3 seconds). And while the 911 Turbo is still able to keep up with the S model in this standard exercise, acceleration to 160 km/h already shows the difference: The Turbo S Coupé takes only 9 seconds flat to reach this speed, as opposed to 9.3 seconds with the 911 Turbo. And when it comes to really high speeds the gap is even wider, the Turbo S accelerating to 200 km/h in 13.6 seconds, 0.8 seconds faster than the 911 Turbo. Top speed is 307 km/h or 190 mph. Another characteristic feature typical of the Turbo S is the brake system with PCCB Porsche Ceramic Composite Brakes fitted as standard.

Motorsport

Turbo Power for a Record Winner

Scoring no less than 16 overall wins in the 24 Hours of Le Mans, Porsche holds an unparalleled record in this great event. And most of these wins were scored with turbocharged power units, most of which once again were close relatives to the six-cylinder 911. In this toughest long-distance race in the world, two 911 GT1s brought home a one-two victory against keen competition in 1998, powered by engines with approximately 600 bhp in principle based on the same standards and configuration as are to be admired in the current 911 Turbo.

By the time of this most recent success in Le Mans, the Porsche 917/10 and 917/30 raced back in 1972 and, respectively, 1973 were already a legend. These racing prototypes with mighty 12-cylinder power units displacing up to 5.4 litres and developing up to 1100 horsepower, were basically the fore-fathers of the 911 Turbo engine in terms of their turbocharger technology. Another forerunner was to be admired on the starting grid in 1974, when the 911 Carrera RSR Turbo, a GT racing car, truly hit the headlines in Le Mans. Maximum output of the turbocharged 2.1-litre six-cylinder at the time was 450 bhp, this avantgarde car just barely missing victory and crossing the finish line in second place.

Starting in 1976, Porsche raced the unforgotten 935 race model, a special turbocharged version of the 911. And right from the start, this new car won the French round-the-clock marathon in an impressive display of power and performance. Indeed, the 935 was so light that lead weights had to be packed into the car in order to reach the prescribed minimum weight limit of 970 kg or 2139 lb. The 2.8-litre power unit developed maximum output of 590 bhp at 7900 rpm, top speed of the Porsche 935 back in 1976 being 336 km/h or 208 mph on the straight in Le Mans, with acceleration from 0 – 200 km/h in a remarkable 8.2 seconds. From 1976 – 1979 these extra-low and dynamic relatives of the 911 were unbeatable in the Manufacturer's World Championship, bringing home no less than four titles in a row. And apart from many other victories, the Porsche 935 also won the 24 Hours of Daytona (USA) each year from 1978 – 1983.

“Baby" was another member of the 935 model family: Reflecting the rules and regulations of the German Motor Racing Championship very popular at the time, a 1.4-litre power unit developing 370 bhp was raced twice in 1977. Without carrying any additional weights, this special version of the 935 weighed in at 710 kilos or 1566 lb. The other extreme was “Moby Dick" in 1978, another special version of the Porsche 935 built uncompromisingly by Norbert Singer, Porsche's Chief Racing Engineer, for high speeds in Le Mans. And indeed, the maximum speed recorded in this case was 366 km/h or 227 mph. For the first time in the history of the 911, the engine came with water-cooled cylinder heads featuring four valves per cylinder. Maximum output of the turbocharged 3.2-litre six-cylinder with four overhead camshafts was 845 bhp.

From 1982 – 1994 the Porsche 956/962 C set the standard in Le Mans, scoring no less than 7 overall victories. Again, their turbocharged power units were developed on the basis of the 911 engine.

One-two victory in the Paris-Dakar Rally

Racing the 959 in the long-distance Paris-Dakar Rally in 1986, Porsche scored yet another one-two victory. Two turbochargers in register configuration gave the engine of this special model maximum output of 400 bhp conveyed to the ground by trendsetting, electronically controlled all-wheel drive. On account of the special transmission ratio chosen in this case, top speed was limited to 210 km/h or 130 mph. Also referred to as the “Mega-911", the Porsche 959 finished first, second and sixth in the 1986 Paris-Dakar Rally, a limited special series of this very special car being homologated and sold for road use.

Moving on to the '90s, Porsche was highly successful in a number of international GT series with the 911 GT2, a car named after its particular class in racing. Driven by private teams, these very special versions of the 911 developed up to 600 turbocharged horsepower. Then the first 911 GT1 was developed for the top GT class, with four works entries in 1996, before it was replaced by a new version of the 911 GT1 in 1998, Porsche's first racing car with a carbon-fibre monocoque chassis. Both models featured 3.2-litre six-cylinder power units with two exhaust gas turbochargers, with the engine block and cylinder heads made of aluminium.