History - Four decades of the 911 Turbo
Sun, 10/23/2011 - 16:39 — admin
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.
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.
1974: The 1st generation - Porsche 911 Turbo
And what lurked beneath this big rear spoiler made even the most experienced Porsche driver gasp for breath: A 3.0-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.
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 3.3-litre 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.
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.Porsche 964 Turbo - last of RWD 911 Turbo
Following a break in production of two years, Porsche presented a new 911 Turbo in 1991: The tweaked 3.3-litre 930-derived 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 . The biggest difference of the 964 design is the coil and damper struts used in favour of the torsion beam suspension providing better damping, springing and geometry.
This 964 is usually regarded as the modern 911 though sharing a body that looks very much like the 930 before it. The introduction of power steering and ABS helps but the greatest leap was the Sports Tiptronic transmission though only for the normal Carrera models. Still with the G50 5-speed manual transmission 0-100 km/h was cleared in just 5.0 seconds and gave the 911 Turbo 3.3 a top speed of 270 km/h.
When Porsche updated this model (considered the 4th generation 911 Turbo) in 1993 to the 911 Turbo 3.6 power was increased by 40 bhp now developing maximum output of 360 bhp. The bodywork sprouted a wilder (993-look) rear wing and got more bling in its alloy wheels. The power increase helped cut the 0-100 km/h time to 4.8 seconds and moved top speed to 280 km/h. Later they developed the lightweight 381 bhp 964 Turbo S and thus began the legacy of the 911 Turbo S.
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.Porsche 996 Turbo - the begining of the water-cooled era
The 996 Porsche 911 Turbo – 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.
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 2001 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.
In 2003 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.
2006: The 7th generation - The 911 Turbo (Type 997)
Rated torque has been increased from 560 to 620Nm. The speed range in which this power is available has also been extended. While the previous model’s maximum torque was available between 2,700 and 4,600 revolutions per minute, the corresponding figures are now 1,950 to 5,000 revs.
These improvements are translated into driving performance. The new 911 Turbo with six-speed manual transmission requires 3.9 seconds for the standard sprint from zero to 100 km/h. The coupé reaches the 200 km/h mark in 12.8 seconds.
And just 3.8 seconds are all it takes for the most powerful series-built 911 model of all time to accelerate from 80 to 120 km/h in fifth gear. Despite these enhanced performance statistics, Porsche developers succeeded in reducing average fuel consumption by one tenth to 12.8 liters per 100 kilometers.
The 911 Turbo with the optionally available Tiptronic S automatic transmission puts in an even more impressive performance. Interaction of this new turbo technology with the appropriately configured Tiptronic S automatic transmission was able to offer the driver even faster acceleration, the Turbo with automatic transmission for the first time rocketing from a standstill to 100 km/h faster than the manual gearbox model in precisely 3.7 secondsvand to reach 200 km/h after a mere 12.2 seconds.. Top speed in both cases was 310 km/h or 192 mph.
The vehicle’s flexibility can be enhanced even further with the optional “Sport Chrono Package Turbo”, available for the first time. Here the driver selects the “sports button” adjacent to the gear lever to activate a short-time “overboost” at full throttle. This increases boost pressure in the mid speed range by 0.2 bar for up to ten seconds; torque rises by 60 to 680 Newtonmeters. The time required by the 911 Turbo with manual transmission for intermediate acceleration from 80 to 120 km/h is reduced by 0.3 seconds to 3.5 seconds.
These performance figures owe themselves to exhaust turbochargers with variable turbine geometry, featuring for the first time in a gasoline engine model. At the heart of this technology are adjustable guide blades, which direct the engine exhaust flow variably and precisely onto the turbine wheel of the exhaust turbocharger. The principle of variable turbine geometry unites the advantages of small and large exhaust turbochargers and leads to a discernable improvement in flexibility and acceleration, particularly at low speeds.
To transfer the available power to the road, the new generation of the 911 Turbo features a redesigned all-wheel drive with an electronically controlled multi-disc clutch. Porsche Traction Management (PTM) ensures variable power distribution to the two driven axles. Depending on the driving conditions, the all-wheel electronics system constantly determine the optimal torque distribution to ensure the best-possible drive.
In practice this translates as high agility on narrow country roads, outstanding traction in rain and snow and optimal active safety even at high speeds. These properties make the Porsche Traction Management system in the new 911 Turbo one of the most powerful and, at the same time, lightest all-wheel systems on the market.
The new 911 Turbo’s driving performance is duly tempered by its brake system, which comprises monobloc fixed-caliper disc brakes with six pistons at the front axle and four at the rear.
In comparison with the Type 996, the diameter of the internally ventilated and perforated brake discs at the front and rear wheels has been increased by 20 millimeters to 350 millimeters. As an option, Porsche is also offering its optimized ceramic brake system, PCCB (Porsche Ceramic Composite Brake). The advantages of this high-tech material mean a reduction of 17 kilograms compared to the standard brake system, excellent fading stability owing to consistent friction values and absolute corrosion resistance. The brakes now have a diameter of 380 millimeters at the front axle and 350 millimeters at the rear.
A characteristic design feature of the new 911 Turbo is the modified front end with its distinctive, tautly drawn cooling air inlets. In conjunction with the standard-equipment oval bi-xenon headlights, they define its unmistakable image. The harmonious front view is enhanced by widely placed and deep-set fog lights and by new LED flashers, which are situated in the lateral air inlets of the front end.
From the rear perspective too, the Turbo takes on a more powerful appearance. This is due first and foremost to its tail end, 22 millimeters wider than that of the previous model, to which the redesigned wing spoiler element has been aligned. It now slopes downward slightly at the sides to nestle into the contours of the rear fenders. The lateral air inlets behind the doors have also been redrawn and, together with the new air ducts, afford a more efficient supply of cooling air to the charge-air intercoolers.The Porsche 997.2 Turbo
This 911 Turbo combines far-reaching innovations in technology with fine tuning and supreme refinement in design. All key features of this high-performance sports car have been significantly improved, the new 911 Turbo combining a substantial improvement in fuel efficiency and lower weight with more power, even higher speed, and enhanced driving dynamics.
Particularly in terms of fuel economy and dynamic performance, the new top-of-therange 911 from Zuffenhausen now stands out even more than before from its competitors in the market.
For the first time in its history the 911 Turbo drops the Mezger derived engine used in the Turbo and GT3/GT2/RS lines. This is the first entirely new engine in the 35-years of the Turbo, coming with features such as Direct Fuel Injection and Porsche’s exclusive turbocharger with variable turbine geometry on a gasoline power unit. As an option, the new six-cylinder may be combined for the first time with Porsche’s seven-speed PDK Doppelkupplungsgetriebe (Double-Clutch Gearbox).
Models equipped with PDK are also available with a new, optional three-spoke steering wheel with gearshift paddles as an alternative to the standard steering wheel with its proven shift buttons.
Fitted firmly on the steering wheel, the right paddle is for shifting up, the left paddle for shifting down. In conjunction with the optional Sport Chrono Package Turbo both the gearshift paddle and the PDK steering wheel with its shift buttons come with integrated displays for Launch Control and the Sport/Sport Plus mode, which are however designed differently on the two steering wheels.
The combination of PDK, Direct Fuel Injection and turbocharging ensures an unprecedented standard of efficiency, agility, responsiveness and performance, the Porsche 911 Turbo reducing CO2 emissions versus its predecessor by almost 18 per cent and therefore ranking unique in its segment also in this respect.
Depending on the configuration of the car, the new top model requires just 11.4 - 11.7 ltr/100 km (equal to 24.8 - 24.1 mpg imp) under the EU5 standard. And unlike most other cars in its segment, the new Turbo avoids the gas guzzler tax in the USA, the special tax imposed on cars with substantial fuel consumption. All this despite acceleration to 100 km/h in 3.4 seconds. Top speed, in turn, is 312 km/h or 194 mph.
The Turbo driver of the future will also enjoy a further improvement in driving dynamics, detailed enhancement of PTM fully controlled all-wheel drive and PSM Porsche Stability Management being further supported by new PTV Porsche Torque Vectoring available as an option. This makes the car even more agile and precise in its steering for an even higher level of driving pleasure.