It was at the Frankfurt Motor Show in 1973 that a silver prototype, perched on the Porsche stand, wowed onlookers with its distinctive appearance. From the familiar sloped 911 engine cover extended a new, wild-looking rear spoiler with air intake louvres and a thick rubber lip around its edges. Visually, the show car looked like the 911 Carrera RS 3.0, a car that had just become available for sale, but the badges on the rear wheel arches made it clear that, in reality, this was a thoroughly new model. The badges said ‘Turbo’, and from this point forward that motif would develop yet another Porsche tradition.
Underneath the rear spoiler and explaining the turbo badges was a flat-6 engine with a single turbocharger. It developed 280 horsepower and enabled a top speed over 160 mph. These sounded like figures from a pure-bred racing machine, and that is essentially what the new car was. Inspired by their motorsport program, engineers at Porsche already had been researching ways to increase engine power for a number of years. Indeed, in 1969 the company built a 6.0-liter flat-16 naturally aspirated ‘Can-Am’ racing engine that produced 770 hp. The engineers calculated that in eventual 7.2-liter form, 880 hp was possible, but in the end it never raced. In fact, it barely even ran because Porsche had another, more promising engine on the test bench, a turbocharged version of the 5.0-liter flat-12 found in the 917. In time, this would become one of the most powerful racing engines in history, with 1,200 horsepower for racing and even more in qualifying trim.
It was with that ambitious program that Porsche’s long relationship with turbocharging began. Following two consecutive championship titles in the unlimited Can-Am series, Porsche then applied what they had learned to the 911. Back in 1969, a 2.0-liter turbo flat ‘six’ from a 911 had actually been tested on the bench, but it was not until early 1973 that road trials began with a 2.7-liter engine boosted by a single turbocharger. It was in this form that the car made its public debut as a ‘concept’ shown at Frankfurt in September of that year, arousing interest everywhere with the huge ‘Turbo’ graphics on the rear haunches.
Undeterred by the political environment in the Middle East and the impending fuel crisis, Porsche forged ahead with the car’s development, and when the production car appeared at the 1974 Paris Motor Show the specification had evolved noticeably. The engine was enlarged to 3.0-liters in order to bolster off-boost performance, and it made a claimed 260 hp at 5,500 rpm and 343 Nm at 4,000 rpm. A new, stronger gearbox handled the torque, but featured only four-speeds, and there was no boost gauge in the cockpit. Even so, the motoring press immediately sang their praise for the new 911. Britain’s Motor magazine even called it “The finest driving machine you can buy”.
The car was clearly quite the performer, but it was also an ambitious step into the future. Turbos were not unheard of in racing, but were still very rare on the street, and the few road cars that did toy with the idea of turbocharging were ultimately unsuccessful. The boost in power resulting from the turbo usually meant a drastic reduction in engine life, but Porsche did not shy away from the design challenges and the company’s engineers applied their characteristically advanced technical knowledge and practicality to the turbo concept.
Within Porsche, there had been debate as to what kind of car the Turbo should really be. Some were of the opinion that it should be more racing-oriented as was the case with the RS versions of the 911, but Chairman Ernst Fuhrmann felt that the Turbo lent itself to the identity of a high-performance GT, with significant creature comforts and a premium price tag. Fuhrmann was the boss, and ever since that has been the basic template for the 911 Turbo.
After a successful first run, for 1978 the 911 Turbo (all Turbos from 1975-1989 were known internally as the ‘930’) underwent a thorough update. Engine displacement went up to 3.3-liters, an intercooler was added to the turbo, the drivetrain was upgraded, a new brake system was added and the tires were wider. Thanks to the intercooler, the 930 made the magic figure of 300 horsepower, and the car became an instant classic. This 930 would last until 1989 with subtle modifications along the way, with the final year of production getting a five-speed gearbox. Its replacement really marks the end of the first phase in life for the Turbo, and it wasn’t until 1991 that the 911 Turbo returned, this time based on the new 964.
This new 964-based Turbo was clearly made with everyday livability in mind, as it had better cockpit ventilation and power steering, but engine power and aerodynamics were better as well, in keeping with Porsche’s tradition of gradual and constant improvement. The new Turbo got a 3.6-liter, 964-based engine in 1993, but this was the last of the rear-drive, single-turbo cars. The next 911 Turbo would take a bigger leap forward and set yet another benchmark for performance cars.
It began with the 993-based Turbo that debuted at the Geneva Motor Show in 1995. The 3.6-liter engine now had not one turbocharger but two, and was controlled by an advanced engine management system. Power jumped to 408 horsepower and 540 Nm or torque, much of which was available from surprisingly low down in the rev range. Just as surprising was the introduction of four-wheel-drive, a feature that has stuck ever since, as well as the new six-speed gearbox.
But possibly even more significant that all of this was the introduction of the 996 Carrera in 1997, the first all-new 911 to date. It was also the first water-cooled 911, and a Turbo version was soon to follow. In Porsche’s R&D center at Weissach, a new motor was concocted and eventually became known as the ‘Mezger’ engine after its designer Hans Mezger, who had actually helped design the engine for the 935/78 ‘Moby Dick’ of 1978, the most extreme racing 911 ever constructed by Porsche. The new 911 Turbo produced 420 hp thanks to its two turbochargers, and top speed peaked just below 200 mph. Another new addition was PSM, the electronic Porsche Stability Management control system, although its intervention was rarely needed.
Once again, the 911 Turbo had redefined performance in a compact, usable package, and this was further developed in 2006 with the advent of the 997-based model, which featured up to 679 Nm through a temporary over-boost function on the turbo. It also introduced the Porsche Traction Management (PTM) multi-plate clutch system to split the torque to the front axle instead of the old viscous coupling, a development like the ‘PSK’ system that debuted on the 959 quite a few years earlier.
In 2010 the second generation 997 Turbo appeared. The ‘Mezger’ motor had been replaced by an all-new 3.8-liter one that featured direct injection. It made 500 horsepower and 700 Nm of torque on over-boost. Porsche was also, after first developing the technology on its turbocharged racing cars a quarter of a century before, finally able to give their 911 Turbo a twin-clutch PDK gearbox. The Turbo S, with 530 horsepower, a 3.3 second 0-62 time, and PDK gearbox, was the ultimate expression of the 911 Turbo until the 991-based version of 2013 proved even more impressive.
History of the 911 Turbo, highlights:
- The original Turbo features the ‘Whale Tail’ spoiler, developed from the 3.0 RS. Later 3.3-liter cars have the ‘Tea Tray’ intercooler spoiler, identified by a flat deck area and a thick rubber lip around the edge
- Porsche overcame turbo lag, the pause in acceleration found lower in the rev, by charge pressure control via an exhaust bypass valve, which until then had only been used in motor sport. This complex control system made it possible to size the turbocharger so it built up more pressure at lower engine speeds and generated more torque
- Production of the 911 Turbo 3.0 totalled 2,876 units by 1977
- When Motor achieved 160.1 mph during its road test of the 3.3 Turbo in 1979, the car became the fastest production car the magazine had tested to date. At 12.3 seconds to 100mph from rest, it was also the quickest in terms of acceleration
- Group B 911 Turbos finished 11th, 13th and 15th at Le Mans in 1983, winning the category outright. They were effectively just lightly-modified road cars
- The original 1973 911 Turbo concept car from the Frankfurt Motor Show survives to this day. Its 3.0 RS body now houses a 3.0 RS engine
- 930 sales in America were halted at the end of 1979 due to emissions regulations. The model returned in 1986 with a catalytic converter
- When it was launched in February of 2000, the 996 Turbo was hailed as the ‘world’s lowest emitting automobile’. This was made possible by four valves per cylinder, water cooling, and the first use of VarioCam Plus variable valve timing.
- The 997 Turbo was the first gasoline-powered production car to feature variable geometry turbochargers, hitherto only available on diesel cars
- The first 911 Turbo to feature four-wheel-drive was the 993-based model introduced in 1995
- The first 911 Turbo to be available with an optional automatic gearbox was the 996-based model introduced in 2000. PDK arrived in 2010
- 20,664 of the original (930) 911 Turbos were built, split between 3,227 examples of the 3.0-liter model and 17,437 of the 3.3-liter. Later production included Targa and Cabriolet derivatives, along with rare ‘slant nose’ models incorporating pop-up headlights
- The most powerful, air-cooled, production line built 911 Turbo ever was the 993 Turbo S model of 1997. It made 430 horsepower
- Continuing the tradition of the 911 Turbo as a technology pioneer, the latest Type 991 model features the world’s first variable front spoiler – powered by pneumatic actuators depending on vehicle speed
- The latest 911 Turbo S can lap the Nürburgring-Nordschleife in 7 min 27 secs – in 1997, the lap time for the Type 993 Turbo was 8 min 12 secs
- The 911 Turbo had an especially prominent fan very early on. Professor Ferry Porsche drove his early 911 Turbo with chassis number 930 770 088 until 16 June, 1980, for a total of 8,200 kms. Equipped with a steel sliding sunroof, air conditioning, brown leather upholstery and many other extras, this car has since been part of the Porsche Museum collection
History of the Porsche 911 Turbo – Photo Gallery
[Source: Porsche AG]