10 Years of Audi TDI Technology: Innovation, Progress and Success

Reply Subscribe

Thread Tools

Search this Thread

06-15-1999, 12:27 PM

Matt Daniels

Guest

Posts: n/a

10 Years of Audi TDI Technology: Innovation, Progress and Success

06/15/9910 Years of Audi TDI Technology: Innovation, Progress and Success At the 1989 German International Motor Show in Frankfurt am Main, Audi presented the world’s first diesel engine for passenger-car use, with direct fuel injection and all-electronic engine management, and gave this revolutionary technology the name TDI. First used in the Audi 100 Avant early in 1990, this remarkable new development on the passenger-car diesel market gave the diesel a totally new image almost overnight: instead of slow-moving, loud and unrefined, it was now agile, smooth and quite exceptionally economical. The Audi TDI achieved a dual emotive effect by uniting dynamic, sporting character with low consumption and a correspondingly useful operating range before having to refuel. One could say that nothing remained of the traditional diesel except its proverbial long life. Ten years of tradition and success thus provide a welcome opportunity to look back, but also to examine future prospects and developments. Audi will continue to pioneer TDI progress in accordance with its famous "Vorsprung durch Technik" slogan and to play a leading part in the competition to supply the products that the market and the customers demand. 10 years of Audi TDI know-how A review 1989: <li>The first 5-cylinder TDI with an output of 88 kW (120 bhp) and 265 newton-metres of torque <li>Axial-piston injection pump operating at a pressure of approx. 900 bar1991: <li>Four-cylinder TDI with an output of 66 kW (90 bhp) and 182 newton-metres of torque <li>Axial-piston injection pump operating at a pressure of 950 bar1993: <li>V8 TDI design study for the Audi ASF Concept Car shown at the Frankfurt Motor Show1994: <li>All Audi TDI engines comply with MVEG II emission limits <li>Five-cylinder TDI with a power output of 103 kW (140 bhp) and 290 newton-metres of torque <li>Axial-piston injection pump operating at a pressure of approx. 1000 bar <li>First Audi TDI-Technical "Auditorium"1995: <li>Four-cylinder TDI with a power output of 81 kW (110 bhp) and 225 newton-metres of torque <li>Axial-piston injection pump operating at 1100 bar Turbocharger with variable turbine eometry (VTG)1997: <li>World's first V6 TDI passenger-car engine, with a power output of 110 kW (150 bhp) and 310 newton-metres of torque <li>Radial-piston injection pump operating at up to 1500 bar, and VTG turbocharger <li>First TDI engine with four valves per cylinder1999: <li>V8 TDI with a power output of 165 kW (225 bhp) and 480 newton-metres of torque <li>Common rail injection system operating at 1350 bar, VTG turbocharger and four valves per cylinder 10 years of the Audi TDI Authority derived from experience Audi benefits from the TDI know-how it has built up during ten years of market presence, and is able to utilise the individual advantages of all the direct-injection systems currently offered for sale in a manner which ideally suits the intended purposes and offers the customer maximum benefit. These systems are: First, the well-proven and successful rotary-pattern injection pump. It produces a well-shaped injection pattern and has a high pressure potential, extending up at the moment as far as 1850 bar. It is easy to install on the engine, can be used on engines with up to six cylinders and has a pilot injection facility. Second, the pump-injector system, which features compact modules for each cylinder of the engine. It is particularly suitable for 3- and 4-cylinder engines with two valves per cylinder, but can in fact be installed on engines with any number of cylinders. Additional advantages are the pilot injection facility and the very high pressure potential of more than 2000 bar. Finally, the common rail system, in which pressure is built up permanently; it permits considerable freedom in determining the pattern of pilot, main and post-injection, and the pressures concerned can be chosen freely even at low engine speeds. This system is straightforward to install on the engine and has particularly compact injectors. Although the maximum pressure is currently in the region of 1350 bar, the system clearly has plenty of future development potential. Audi’s TDI technology The outlook By means of the forthcoming new TDI models displayed on the occasion of the second Audi TDI Technology Auditorium ("10 Years of the TDI") in June 1999 at Graz University, Audi supplies evidence of the experience it has accumulated in the past ten years: they are the Audi A8 3.3 TDI Quattro (165 kW/225 bhp) with common rail system, the Audi A6/A6 Avant 2.5 TDI (132 kW/165 bhp) and the new VP44-S3 radial-piston injection pump, and finally the A4/A4 Avant 1.9 TDI (85 kW/115 bhp) with high-pressure pump-injector system. All these models are available for the first time for road testing. The market launches for these models, which are described below in brief, are scheduled for the end of this year or the beginning of the next. The Audi A8 3.3 TDI quattro with 165 kW engine Common rail fuel injection: uniform high pressure fuel supply to all eight cylinders With the new V8 engine (with four valves per cylinder) installed in the A8 3.3 TDI quattro, the first eight-cylinder direct-injection engine which complies with the stringent EU III exhaust emission limits, Audi is establishing a further landmark in the history of passenger-car direct-injection diesels. Common-rail injection, a water-cooled charge-air intercooler, four valves per cylinder and two turbochargers with variable turbine geometry are the principal technical features. With torque of 480 newton-metres available all the way from engine speeds of 1800 to 3000 rpm, and a power output of 165 kW (225 bhp), the A8 3.3 TDI quattro is the flagship of the Audi TDI model programme. As well as the excellent performance, the car’s low noise levels are a notable feature. Over the entire engine-speed range, the new V8 TDI matches the quality achieved by an eight-cylinder spark-ignition engine. With a total fuel consumption of approx. 9.7 litres per 100 kilometres according to the 93/116/EC test method, the car’s average operating range before refuelling is some 930 kilometres – a peak value for a car in the top automobile league.Spontaneous response to accelerator movement and an impressive 0 to 100 km/h time of only 8.2 seconds make this car, which with its top speed of 242 km/h would normally be regarded as a "long-distance runner", into a most impressive sprinter as well. The Audi A6/A6 Avant 2.5 TDI with 132 kW engine Rotary-piston injection pump: well-proven and up-to-date The first-ever Audi TDI engine was the 2.5 TDI, introduced for the Audi 100 Avant in 1989 and the precursor of a hitherto unparalleled success story. The newest and best-performing member of the family of cars equipped with a radial-piston injection pump is now once again called the 2.5 TDI, but its badge sports a small red flag: since the end of 1994 Audi has used this symbol to identify the most sporting model in any model line, with the same engine size as the others. The new engine will be premiered in the Audi A6 and A6 Avant. With a power output of 132 kW (180 bhp) and a torque of 370 Nm all the way from 1500 rpm to 2500 rpm engine speed, it is among the world’s leading series-production engines for specific power output, at 53 kW (72 bhp) per litre. The list of noteworthy technical features to be found on this latest Audi engine is a long and interesting one: four valves per cylinder with centrally located injector, turbocharger with electronically controlled variable turbine geometry (VTG), the latest VP44-S3 radial-piston injection pump with three plungers, capable of achieving a maximum injection pressure of 1850 bar, charge-air intercooling, exhaust gas recirculation, pilot injection controlled by solenoid valve, a first-stage catalytic converter located close to the engine and followed by an oxidating converter. Whichever of the transmissions is specified with this engine, it always complies with the tough EU III exhaust emission limits. Capable as it is of accelerating from 0 to 100 km/h in under nine seconds and reaching a top speed in excess of 220 km/h, this new top V6 TDI in the Audi A6 quattro can genuinely be described as a sporting thoroughbred. All the more remarkably, it needs only a miserly 8 litres of diesel oil per 100 kilometres (total consumption figure according to the 93/116/EC test method, giving it an operating range that may well exceed 870 kilometres before refuelling is necessary. Together with the two 1.9 TDI and four transmission versions of the 2.5 TDI with a power output of 110 kW (150 bhp) in either the A6 or A6 Avant, Audi can justly claim that this superb V6 TDI engine represents a versatile and unsurpassed offer in the midsize car class. The Audi A4 1.9 TDI with 85 kW engine Pump-injector injection system: ultra-high pressures for maximum efficiency The high-pressure pump-injection system achieves the highest injection pressures currently available in any direct-injection process. The associated fine atomisation of the fuel ensures that a high degree of thermodynamic efficiency is attained and the highest specific torque per litre is at the driver’s disposal. This system also permits controlled pilot injection as a means of ensuring low engine noise levels and minimum emissions. The 85 kW (115 bhp) A4 1.9 TDI develops the most remarkable peak torque of 285 Nm at 1900 rpm and is therefore always exceptionally flexible. It accelerates from 0 to 100 km/h in 10.5 seconds and, with a manual-gearbox fitted, can exceed the 200 km/h mark on the way to its top speed. Total fuel consumption according to the 93/116/EC test method will be in the region of 5.3 litres per 100 kilometres. This new engine will gradually supersede all transmission versions of the existing 1.9-litre TDI with rotary-piston injection pump, which develops 81 kW (110 bhp). As the largest TDI engine in the A4 programme, it will have to perform the important role of TDI standard-bearer, and will certainly be capable of setting new standards in terms of consumption and power flow. AUDI AG, Communication - Product and Technology D-85045 Ingolstadt, Germany phone: (+49) - 841-89-92593 telefax: (+49) - 841- 89-32817

Reply Like