Thirty Years of the Porsche 911 Turbo
as at http://www.germancarfans.com/news.cfm/newsid/2040825.001/porsche/1.html
911 Turbo 3.6 Coupé 2 (MY 1993)
Putting on the Pressure "" for Three Decades (short story)
It was at the 1974 Paris Motor Show that Porsche presented a high-performance sports car setting an outstanding new benchmark in terms of acceleration, torque, dynamic performance, and brake power: the 911 Turbo 3.0. Maximum output of this outstanding sports car was 260 bhp from three litres engine capacity. Achieving a top speed with this power of 250 km/h or 155 mph, the Porsche 911 Turbo 3.0 was for a long time Germany's fastest road-going sports car. A comparison with the current successor to the first Turbo, the Porsche 911 Turbo S in 2004, clearly shows, however, that the process of development never comes to an end: Maximum output of the current model is 450 bhp from 3.6 litres capacity, giving the car a top speed of 307 km/h or 190 mph.
The 911 Turbo had a particularly prominent friend and supporter right from the start: Professor Ferdinand ("Ferry") Porsche drove one of the Turbos from the very first series with chassis number 930 770 088 for a total of 8,200 kilometres until 16 June 1980. Ever since this very special model featuring a steel sliding roof, air conditioning, brown leather upholstery and further extras has been one of the outstanding exhibits at the Porsche Museum.
The original idea in 1974 was to build the first 911 Turbo in a production run of 1,000 units. But to put it mildly, this forecast was slightly off the mark, total production of the 911 Turbo from 1974 "" 1989 amounting to almost 21,000 units.
Following a break in production of two years, the next Turbo powered by a 320 bhp 3.3-litre engine was launched in 1991, this time based on the 911 model series code-named the 964 within the Company. The next generation of the 911 Turbo (993 model series) introduced in 1995 again set new standards in the world of the sports car: The power unit of this model was based on the air-cooled 3.6-litre engine of the 911 Carrera and featured two turbochargers boosting output to 408 bhp at 5750 rpm. Another significant innovation was the introduction of all-wheel drive carried over from the 911 Carrera 4. Total production of this 993-series Turbo was 6,314 units.
The 996 version of the 911 Turbo introduced in the year 2000 maintained Porsche's all-wheel drive and bi-turbo technology. And it also introduced composite ceramic brake discs as a feature which has now been available for four years.
In its basic characteristics, the Turbo has remained unchanged for 30 years: Throughout all this time, the emphasis has been on exceptional power and performance combined with equally superior comfort and everyday motoring qualities "" features which have characterised all models and versions over the years.
Fast, Dynamic, Comfortable (long story)
Particularly one of the cars on display at the Paris Motor Show back in 1974 aroused huge attention right from the start through its exceptional looks and visible features: The biggest eye-catcher was a large rear wing on the engine lid, perforated by ventilation slots and framed by a thick rubber "lip". And what lurked beneath this big rear spoiler made even the most experienced Porsche driver gasp for breath: A three-litre six-cylinder horizontally-opposed power unit with a turbocharger, 260 bhp maximum output, a top speed of 250 km/h or 155 mph, and the bite of thoroughbred racing machine. And that, basically, was what it was: The Porsche 911 Turbo was not only the fastest road-going German sports car, but also the forerunner to a genuine turbo boom.
And, most definitely, it was also a bold step into the future. While turbocharged engines were no longer that unusual in motorsport, only one manufacturer had attempted to introduce such an engine in a road-going car so far "" and had suffered big problems in the process. The reason, quite simply, was that the high power provided by the turbocharger generally meant a significant reduction in engine life, making the engine very sensitive and making the car challenging "" if not to say, difficult "" to drive. In a nutshell, therefore, the turbo engine was regarded as hard "" or even impossible "" to handle.
The basic concept: a racing car for the road
Porsche's engineers, however, proved superior in their know-how and practical implementation of the concept: The original plan was to build a small series of Gran Turismo sports cars derived from motor racing and now legal for road use. Back then the GT regulations called for a production volume of 400 units. But since Porsche saw no way to sell that many cars to racing drivers, the Company decided to make the competition model street-legal, making only a few concessions to motoring comfort. The turbocharged engine was of course the heart of the new car from the very beginning: First, Porsche had already gained experience with this technology in the 12-cylinder 917/10 and 917/30 race cars developing maximum output of up to 1100 bhp. Second, the general feeling was that the 911 power unit originally introduced in 1983 with 130 bhp no longer offered adequate potential for a further increase in power and victory on the race track, without enjoying the benefits of turbocharging. Accordingly, while the normal-aspiration power unit of the RSR 3.0 upgraded for motorsport in 1974 developed maximum output of 330 bhp, the 911 Carrera RSR 2.1 raced in the same year developed 500 bhp with the help of a turbocharger.
With the minimum weight for GT racing cars being increased in spring 1974, Porsche saw the opportunity to build not a racing car in disguise, but rather a luxury high-performance sports car as the foundation for the racing version. So from March 1974 to the introduction of the new model in October of the same year, the new concept was converted into reality for the flagship within the Porsche range (fully homologated for the road, of course). To overcome the disadvantages of the turbocharged power unit such as inadequate power and acceleration at low engine speeds, Porsche introduced a concept of turbocharger pressure control by means of an exhaust gas by-pass valve previously only seen in motorsport. Benefitting from this sophisticated management concept, Porsche's engineers were able to suitably modify the dimensions of the turbocharger to build up more pressure at low engine speeds and thus develop extra torque in the process. To keep this more than ample power under control, Porsche's engineers used their extensive experience in motorsport also for the brakes, fitting the car with inner-vented disc brakes complete with aluminium brake callipers originally featured in the Porsche 917 racing car.
Instead of 400 cars, the objective Porsche now set itself was to build 1,000 units of the 911 Turbo 3.0. But this forecast soon proved completely inadequate, production of the 911 Turbo 3.0 featuring amenities widely recognised as luxurious at the time such as electric window lifts and a stereo cassette radio amounting to 2,876 units by 1977.
1977: the Porsche Turbo breaks the magic mark of 300 bhp
With deliveries of the Porsche 911 Turbo starting in spring 1975, nobody really believed that a car of this calibre might ever require even more power. But they were wrong! In 1977 Porsche introduced the 911 Turbo 3.3 powered by an even larger engine now, with the help of an intercooler, developing that magic figure of 300 bhp. Code-named the 930 model series, this sports car remains a legend to this day. Porsche's next major breakthrough came in 1982, in a process of ongoing development: Thoroughly optimising the fuel supply system, Porsche's engineers were able to significantly reduce fuel consumption while maintaining the same high level of power: Instead of 20 litres in city traffic (14.1 mpg Imp), fuel consumption was now just 15.5 litres (18.2 mpg Imp), the corresponding improvement at a steady speed of 120 km/h or 75 mph being 11.8 litres (23.9 mpg Imp) instead of 15.3 litres (18.5 mpg Imp) so far.
911 Turbo 3.3. Targa and Cabriolet (MY 1987)
In 1987 the Coupé version was joined by a Targa and a Convertible. At an initial price of DM 152,000, customers received one of the fastest open cars in the world coming as a no-cost option with electrical operation of the roof. Just one year later, five-speed transmission replaced the former four-speed gearbox, close gear increments serving to keep turbocharger pressure even more consistent while shifting gears and improving acceleration from a standstill to 100 km/h by 0.2 seconds to 5.2 seconds.
By 1989 the Porsche Turbo became the fastest best seller in the German market, with sales amounting to almost 21,000 units hardly modified in their exterior design and appearance.
Following a break in production of two years, Porsche presented a new 911 Turbo in 1991: The 3.3-litre power unit now developed maximum output of 320 bhp, the new car being based on the 911 model series code-named the 964 within the Company and by the connoisseur. When Porsche modified this model in 1993, power was increased in the process, the 911 Turbo 3.6 now developing maximum output of 360 bhp.
911 Turbo 3.3 Coupé 1 (MY 1992)
1995: enhanced fuel economy setting a new standard in the sports car segment
Entering the 1994 model year, the 964 model series was replaced by the 993. But the new Turbo in the 911 model range took a bit more time coming, the next Turbo generation entering the market in 1995 and immediately setting a new standard once again: The power unit of this 911 Turbo based on the air-cooled 3.6-litre engine of the 911 Carrera and featuring two turbochargers developed maximum output of 408 bhp at 5750 rpm. Acceleration from 0 "" 100 km/h came in 4.3 seconds, top speed was 293 km/h or 182 mph. The exhaust system featured two metal-based catalytic converters and four oxygen sensors. A significant contribution to superior environmental protection typical of Porsche to this very day was made by the on-board diagnosis system II (OBD II). Fitted worldwide in all 911 Turbos, this sophisticated system permanently supervises all components relevant to exhaust emissions, immediately detecting any defects and activating a warning light in the cockpit. As a result, the 993-series Turbo was lauded the world over for its particularly clean exhaust emissions.
Yet another outstanding innovation was all-wheel drive carried over from the 911 Carrera 4 in the interest of optimised driving behaviour, traction and stability on the road. In the same process Porsche's engineers re-designed both the front and rear end, adapting the side-sills to the wider wheel arches. The single-piece front end now came with even larger air scoops, yet another new development being the rear spoiler fixed in position. Air resistance was optimised by the air flow lip at the bottom of the front air dam and by improved flow conditions throughout the front end of the car as a whole, lift forces being reduced in the process to virtually zero both front and rear. Production of this version of the 911 Turbo amounted to 6,314 units.
911 Turbo 3.6 Coupé (MY 1996)
Entering the year 2000: more power, greater economy
The current Porsche 911 Turbo (the 996 model series) "" again featuring four-wheel drive and bi-turbo technology "" is not only one of the fastest and most powerful sports cars in the world, but also won the title of the "World's Cleanest Car" when introduced in February 2000. The abbreviation "LEV" used above all in the USA stands for "Low Emission Vehicle" "" and Porsche's extra-clean Turbo fulfils this strict emission standard in the same way as it complies with the EU 3 or D4 standards. Fuel consumption, in turn, has been reduced once again from the former model already widely lauded for its fuel economy by another 18 per cent to 12.9 litres/100 km (21.9 mpg Imp) in the composite EU cycle. And exhaust emissions are down by an equally impressive 13 per cent.
Improvements of this kind are made possible by four-valve technology, water cooling and, in particular, VarioCam Plus serving to adjust the camshafts and vary valve lift as required. Indeed, it is fair to say that VarioCam Plus combines two engine concepts in one, serving to reduce fuel consumption and exhaust emissions and improve motoring refinement all in one.
The catalytic converters are right behind the turbochargers, the first, smaller catalyst taking effect very soon after the engine is started cold. The main catalyst, in turn, is designed for optimum conversion of exhaust emissions with the engine at normal operating temperature. On-board diagnosis (OBD) checks, as on the 993-series Turbo, whether all components and functions relevant to exhaust emissions are working properly. OBD immediately detects even the slightest deviation from target figures by consistently monitoring exhaust emissions with electronic accuracy, any defects being reported by a display in the cockpit.
Ceramic brake discs available as an option
The current Turbo model stands out clearly from the other models in the 911 Carrera (996-series) range through its striking air scoops at the front. The rear end of the car, in turn, is characterised by a newly designed wing as well as the air intakes and outlets for the intercooler. The car's impressive specifications and performance data are 420 bhp maximum output, acceleration from 0 "" 100 km/h in 4.2 seconds, and a top speed of 305 km/h or 189 mph. And since autumn 2000, the Turbo has also been available with composite ceramic brake discs.
Despite this ongoing process of development, the 911 Turbo has retained its character throughout three decades: Outstanding performance, supreme acceleration and superior luxury (five-speed automatic transmission, Tiptronic S, leather upholstery) as well as impressive quality and lasting value have enabled this dynamic sports car to become a genuine classic in the course of the last thirty years, a car which already today holds a unique position in the world of motoring.
911 Turbo MY 2004
Power Unit
More Air for More Performance
For a long time now, the word "turbo" has become a synonym in modern language for exceptional power and performance. And the Porsche 911 Turbo has contributed most significantly to this special meaning of a special word.
The principle of this technology is clear and straightforward: The exhaust gas flowing out of the engine accelerates a small turbine wheel to high speeds (up to 90,000 rpm, for example, on the first 911 Turbo back in 1974). Via a shaft, this turbine wheel drives a second rotor wheel forcing air into the combustion chambers. The more air gets into the cylinders in this way, the more oxygen is available and is able to burn together with the fuel. The obvious result is an increase in engine output. Hardly any additional components or mechanical functions are required for operating the turbocharger. Instead, the system uses the residual energy in the exhaust gas, giving it a fundamental benefit over a compressor applying the supercharging principle.
To build up adequate pressure at low speeds while not overtaxing the engine at high speeds, a by-pass valve maintains a stable pressure balance, ensuring that turbocharger pressure does not exceed the maximum limit allowed. While on the first Porsche 911 Turbo this limit was 0.8 bar, there was still a certain time-lag back then before the turbine responded. This, in turn, made the engine cut in with its extra power rather abruptly, leading to well-known expressions such as "turbo gap" and "turbo boom".
High torque
Turbocharged engines develop their maximum output at relatively low engine speeds. The first 911 Turbo, for example, reached its maximum power of 260 bhp at 5500 rpm. And this relatively low level of engine speed remains unchanged to this day, the current Turbo S entering the market in summer 2004 reaching its maximum output of 450 bhp at 5700 rpm. While a sports engine without turbocharging requires not only far higher speeds in order to develop the same kind of power, turbo technology offers the additional advantage of developing superior torque at low engine speeds: The Turbo S, for example, generates 620 Newton-metres or 457 lb-ft of torque between 3500 and 4500 rpm.
Up to 1995 the exhaust pipes from the two rows of cylinders on the flat-six power unit were merged to form one unit driving a common turbocharger. Then, starting with the 993 model series in 1995, two turbochargers "" one for each row of cylinders "" took over the function of building up the appropriate pressure. Today the appropriate technical layout and electronic management ensure a the right kind of engine response and give the driver perfect control of engine power on the current 911 Turbo, thus setting the standard for high-performance power units also in this respect.
Yet another feature makes the engine of the Turbo simply ideal for a luxurious Gran Turismo sports car: the turbocharger in the exhaust system acts as an additional silencer. This explains why turbocharged engines are exceptionally quiet, requiring only a small silencer to comply with strict noise limits.
911 Turbo 3.0 Coupé (MY 1975)
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.
911 Carrera RSR Turbo 2.1 (1974)
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.
as at http://www.germancarfans.com/news.cfm/newsid/2040825.001/porsche/1.html
911 Turbo 3.6 Coupé 2 (MY 1993)
Putting on the Pressure "" for Three Decades (short story)
It was at the 1974 Paris Motor Show that Porsche presented a high-performance sports car setting an outstanding new benchmark in terms of acceleration, torque, dynamic performance, and brake power: the 911 Turbo 3.0. Maximum output of this outstanding sports car was 260 bhp from three litres engine capacity. Achieving a top speed with this power of 250 km/h or 155 mph, the Porsche 911 Turbo 3.0 was for a long time Germany's fastest road-going sports car. A comparison with the current successor to the first Turbo, the Porsche 911 Turbo S in 2004, clearly shows, however, that the process of development never comes to an end: Maximum output of the current model is 450 bhp from 3.6 litres capacity, giving the car a top speed of 307 km/h or 190 mph.
The 911 Turbo had a particularly prominent friend and supporter right from the start: Professor Ferdinand ("Ferry") Porsche drove one of the Turbos from the very first series with chassis number 930 770 088 for a total of 8,200 kilometres until 16 June 1980. Ever since this very special model featuring a steel sliding roof, air conditioning, brown leather upholstery and further extras has been one of the outstanding exhibits at the Porsche Museum.
The original idea in 1974 was to build the first 911 Turbo in a production run of 1,000 units. But to put it mildly, this forecast was slightly off the mark, total production of the 911 Turbo from 1974 "" 1989 amounting to almost 21,000 units.
Following a break in production of two years, the next Turbo powered by a 320 bhp 3.3-litre engine was launched in 1991, this time based on the 911 model series code-named the 964 within the Company. The next generation of the 911 Turbo (993 model series) introduced in 1995 again set new standards in the world of the sports car: The power unit of this model was based on the air-cooled 3.6-litre engine of the 911 Carrera and featured two turbochargers boosting output to 408 bhp at 5750 rpm. Another significant innovation was the introduction of all-wheel drive carried over from the 911 Carrera 4. Total production of this 993-series Turbo was 6,314 units.
The 996 version of the 911 Turbo introduced in the year 2000 maintained Porsche's all-wheel drive and bi-turbo technology. And it also introduced composite ceramic brake discs as a feature which has now been available for four years.
In its basic characteristics, the Turbo has remained unchanged for 30 years: Throughout all this time, the emphasis has been on exceptional power and performance combined with equally superior comfort and everyday motoring qualities "" features which have characterised all models and versions over the years.
Fast, Dynamic, Comfortable (long story)
Particularly one of the cars on display at the Paris Motor Show back in 1974 aroused huge attention right from the start through its exceptional looks and visible features: The biggest eye-catcher was a large rear wing on the engine lid, perforated by ventilation slots and framed by a thick rubber "lip". And what lurked beneath this big rear spoiler made even the most experienced Porsche driver gasp for breath: A three-litre six-cylinder horizontally-opposed power unit with a turbocharger, 260 bhp maximum output, a top speed of 250 km/h or 155 mph, and the bite of thoroughbred racing machine. And that, basically, was what it was: The Porsche 911 Turbo was not only the fastest road-going German sports car, but also the forerunner to a genuine turbo boom.
And, most definitely, it was also a bold step into the future. While turbocharged engines were no longer that unusual in motorsport, only one manufacturer had attempted to introduce such an engine in a road-going car so far "" and had suffered big problems in the process. The reason, quite simply, was that the high power provided by the turbocharger generally meant a significant reduction in engine life, making the engine very sensitive and making the car challenging "" if not to say, difficult "" to drive. In a nutshell, therefore, the turbo engine was regarded as hard "" or even impossible "" to handle.
The basic concept: a racing car for the road
Porsche's engineers, however, proved superior in their know-how and practical implementation of the concept: The original plan was to build a small series of Gran Turismo sports cars derived from motor racing and now legal for road use. Back then the GT regulations called for a production volume of 400 units. But since Porsche saw no way to sell that many cars to racing drivers, the Company decided to make the competition model street-legal, making only a few concessions to motoring comfort. The turbocharged engine was of course the heart of the new car from the very beginning: First, Porsche had already gained experience with this technology in the 12-cylinder 917/10 and 917/30 race cars developing maximum output of up to 1100 bhp. Second, the general feeling was that the 911 power unit originally introduced in 1983 with 130 bhp no longer offered adequate potential for a further increase in power and victory on the race track, without enjoying the benefits of turbocharging. Accordingly, while the normal-aspiration power unit of the RSR 3.0 upgraded for motorsport in 1974 developed maximum output of 330 bhp, the 911 Carrera RSR 2.1 raced in the same year developed 500 bhp with the help of a turbocharger.
With the minimum weight for GT racing cars being increased in spring 1974, Porsche saw the opportunity to build not a racing car in disguise, but rather a luxury high-performance sports car as the foundation for the racing version. So from March 1974 to the introduction of the new model in October of the same year, the new concept was converted into reality for the flagship within the Porsche range (fully homologated for the road, of course). To overcome the disadvantages of the turbocharged power unit such as inadequate power and acceleration at low engine speeds, Porsche introduced a concept of turbocharger pressure control by means of an exhaust gas by-pass valve previously only seen in motorsport. Benefitting from this sophisticated management concept, Porsche's engineers were able to suitably modify the dimensions of the turbocharger to build up more pressure at low engine speeds and thus develop extra torque in the process. To keep this more than ample power under control, Porsche's engineers used their extensive experience in motorsport also for the brakes, fitting the car with inner-vented disc brakes complete with aluminium brake callipers originally featured in the Porsche 917 racing car.
Instead of 400 cars, the objective Porsche now set itself was to build 1,000 units of the 911 Turbo 3.0. But this forecast soon proved completely inadequate, production of the 911 Turbo 3.0 featuring amenities widely recognised as luxurious at the time such as electric window lifts and a stereo cassette radio amounting to 2,876 units by 1977.
1977: the Porsche Turbo breaks the magic mark of 300 bhp
With deliveries of the Porsche 911 Turbo starting in spring 1975, nobody really believed that a car of this calibre might ever require even more power. But they were wrong! In 1977 Porsche introduced the 911 Turbo 3.3 powered by an even larger engine now, with the help of an intercooler, developing that magic figure of 300 bhp. Code-named the 930 model series, this sports car remains a legend to this day. Porsche's next major breakthrough came in 1982, in a process of ongoing development: Thoroughly optimising the fuel supply system, Porsche's engineers were able to significantly reduce fuel consumption while maintaining the same high level of power: Instead of 20 litres in city traffic (14.1 mpg Imp), fuel consumption was now just 15.5 litres (18.2 mpg Imp), the corresponding improvement at a steady speed of 120 km/h or 75 mph being 11.8 litres (23.9 mpg Imp) instead of 15.3 litres (18.5 mpg Imp) so far.
911 Turbo 3.3. Targa and Cabriolet (MY 1987)
In 1987 the Coupé version was joined by a Targa and a Convertible. At an initial price of DM 152,000, customers received one of the fastest open cars in the world coming as a no-cost option with electrical operation of the roof. Just one year later, five-speed transmission replaced the former four-speed gearbox, close gear increments serving to keep turbocharger pressure even more consistent while shifting gears and improving acceleration from a standstill to 100 km/h by 0.2 seconds to 5.2 seconds.
By 1989 the Porsche Turbo became the fastest best seller in the German market, with sales amounting to almost 21,000 units hardly modified in their exterior design and appearance.
Following a break in production of two years, Porsche presented a new 911 Turbo in 1991: The 3.3-litre power unit now developed maximum output of 320 bhp, the new car being based on the 911 model series code-named the 964 within the Company and by the connoisseur. When Porsche modified this model in 1993, power was increased in the process, the 911 Turbo 3.6 now developing maximum output of 360 bhp.
911 Turbo 3.3 Coupé 1 (MY 1992)
1995: enhanced fuel economy setting a new standard in the sports car segment
Entering the 1994 model year, the 964 model series was replaced by the 993. But the new Turbo in the 911 model range took a bit more time coming, the next Turbo generation entering the market in 1995 and immediately setting a new standard once again: The power unit of this 911 Turbo based on the air-cooled 3.6-litre engine of the 911 Carrera and featuring two turbochargers developed maximum output of 408 bhp at 5750 rpm. Acceleration from 0 "" 100 km/h came in 4.3 seconds, top speed was 293 km/h or 182 mph. The exhaust system featured two metal-based catalytic converters and four oxygen sensors. A significant contribution to superior environmental protection typical of Porsche to this very day was made by the on-board diagnosis system II (OBD II). Fitted worldwide in all 911 Turbos, this sophisticated system permanently supervises all components relevant to exhaust emissions, immediately detecting any defects and activating a warning light in the cockpit. As a result, the 993-series Turbo was lauded the world over for its particularly clean exhaust emissions.
Yet another outstanding innovation was all-wheel drive carried over from the 911 Carrera 4 in the interest of optimised driving behaviour, traction and stability on the road. In the same process Porsche's engineers re-designed both the front and rear end, adapting the side-sills to the wider wheel arches. The single-piece front end now came with even larger air scoops, yet another new development being the rear spoiler fixed in position. Air resistance was optimised by the air flow lip at the bottom of the front air dam and by improved flow conditions throughout the front end of the car as a whole, lift forces being reduced in the process to virtually zero both front and rear. Production of this version of the 911 Turbo amounted to 6,314 units.
911 Turbo 3.6 Coupé (MY 1996)
Entering the year 2000: more power, greater economy
The current Porsche 911 Turbo (the 996 model series) "" again featuring four-wheel drive and bi-turbo technology "" is not only one of the fastest and most powerful sports cars in the world, but also won the title of the "World's Cleanest Car" when introduced in February 2000. The abbreviation "LEV" used above all in the USA stands for "Low Emission Vehicle" "" and Porsche's extra-clean Turbo fulfils this strict emission standard in the same way as it complies with the EU 3 or D4 standards. Fuel consumption, in turn, has been reduced once again from the former model already widely lauded for its fuel economy by another 18 per cent to 12.9 litres/100 km (21.9 mpg Imp) in the composite EU cycle. And exhaust emissions are down by an equally impressive 13 per cent.
Improvements of this kind are made possible by four-valve technology, water cooling and, in particular, VarioCam Plus serving to adjust the camshafts and vary valve lift as required. Indeed, it is fair to say that VarioCam Plus combines two engine concepts in one, serving to reduce fuel consumption and exhaust emissions and improve motoring refinement all in one.
The catalytic converters are right behind the turbochargers, the first, smaller catalyst taking effect very soon after the engine is started cold. The main catalyst, in turn, is designed for optimum conversion of exhaust emissions with the engine at normal operating temperature. On-board diagnosis (OBD) checks, as on the 993-series Turbo, whether all components and functions relevant to exhaust emissions are working properly. OBD immediately detects even the slightest deviation from target figures by consistently monitoring exhaust emissions with electronic accuracy, any defects being reported by a display in the cockpit.
Ceramic brake discs available as an option
The current Turbo model stands out clearly from the other models in the 911 Carrera (996-series) range through its striking air scoops at the front. The rear end of the car, in turn, is characterised by a newly designed wing as well as the air intakes and outlets for the intercooler. The car's impressive specifications and performance data are 420 bhp maximum output, acceleration from 0 "" 100 km/h in 4.2 seconds, and a top speed of 305 km/h or 189 mph. And since autumn 2000, the Turbo has also been available with composite ceramic brake discs.
Despite this ongoing process of development, the 911 Turbo has retained its character throughout three decades: Outstanding performance, supreme acceleration and superior luxury (five-speed automatic transmission, Tiptronic S, leather upholstery) as well as impressive quality and lasting value have enabled this dynamic sports car to become a genuine classic in the course of the last thirty years, a car which already today holds a unique position in the world of motoring.
911 Turbo MY 2004
Power Unit
More Air for More Performance
For a long time now, the word "turbo" has become a synonym in modern language for exceptional power and performance. And the Porsche 911 Turbo has contributed most significantly to this special meaning of a special word.
The principle of this technology is clear and straightforward: The exhaust gas flowing out of the engine accelerates a small turbine wheel to high speeds (up to 90,000 rpm, for example, on the first 911 Turbo back in 1974). Via a shaft, this turbine wheel drives a second rotor wheel forcing air into the combustion chambers. The more air gets into the cylinders in this way, the more oxygen is available and is able to burn together with the fuel. The obvious result is an increase in engine output. Hardly any additional components or mechanical functions are required for operating the turbocharger. Instead, the system uses the residual energy in the exhaust gas, giving it a fundamental benefit over a compressor applying the supercharging principle.
To build up adequate pressure at low speeds while not overtaxing the engine at high speeds, a by-pass valve maintains a stable pressure balance, ensuring that turbocharger pressure does not exceed the maximum limit allowed. While on the first Porsche 911 Turbo this limit was 0.8 bar, there was still a certain time-lag back then before the turbine responded. This, in turn, made the engine cut in with its extra power rather abruptly, leading to well-known expressions such as "turbo gap" and "turbo boom".
High torque
Turbocharged engines develop their maximum output at relatively low engine speeds. The first 911 Turbo, for example, reached its maximum power of 260 bhp at 5500 rpm. And this relatively low level of engine speed remains unchanged to this day, the current Turbo S entering the market in summer 2004 reaching its maximum output of 450 bhp at 5700 rpm. While a sports engine without turbocharging requires not only far higher speeds in order to develop the same kind of power, turbo technology offers the additional advantage of developing superior torque at low engine speeds: The Turbo S, for example, generates 620 Newton-metres or 457 lb-ft of torque between 3500 and 4500 rpm.
Up to 1995 the exhaust pipes from the two rows of cylinders on the flat-six power unit were merged to form one unit driving a common turbocharger. Then, starting with the 993 model series in 1995, two turbochargers "" one for each row of cylinders "" took over the function of building up the appropriate pressure. Today the appropriate technical layout and electronic management ensure a the right kind of engine response and give the driver perfect control of engine power on the current 911 Turbo, thus setting the standard for high-performance power units also in this respect.
Yet another feature makes the engine of the Turbo simply ideal for a luxurious Gran Turismo sports car: the turbocharger in the exhaust system acts as an additional silencer. This explains why turbocharged engines are exceptionally quiet, requiring only a small silencer to comply with strict noise limits.
911 Turbo 3.0 Coupé (MY 1975)
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.
911 Carrera RSR Turbo 2.1 (1974)
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.
