The TDI offensive from Audi - Lot's of TDI stuff, yay!

The TDI Offensive from Audi
The New Power

Audi is stepping on the accelerator in the U.S. when it comes to diesel. In a few months, the brand with the four rings will begin series production of the world’s cleanest diesel – the 3.0 TDI with its ultra low emission system. As the inventor and continuous pioneer in TDI technology, Audi possesses a wide range of highly modern diesel engines. They combine muscular power with astonishingly low consumption levels, and have proven their superiority on the road as well as on motor sports race tracks.

The Audi Q7 3.0 TDI

A vigorous powerhouse of an engine pulsates under the hood of the Audi Q7 3.0 TDI. With a displacement of three liters, the V6 generates an impressive 221 hp and a torque 406 lb/ft. This maximum level of tractive force is available at 1,750 to 2,750 rpm – providing the driver with a vigorous power surge in all ranges.

The four valve engine is extremely compact – measuring only 440 millimeters (17.3 inches) in length. The cylinder housing that features a 90 degree cylinder angle is constructed from high strength vermicular graphite cast iron, which is 15 percent lighter in weight than conventional cast iron. Despite its unsurpassed strength, the powerful TDI weighs a mere 226 kilograms (498.2 pounds). Its auxiliaries and camshafts are driven by maintenance free chains that run in a space saving position in back of the engine. Low friction roller cam followers with hydraulic valve clearance compensation work in the cylinder head. Quickstart heater plugs are adapted to extremely cold temperatures – they heat up to more than 1,800° Fahrenheit within the space of two seconds.

Common rail system for quiet running

Mixture preparation is performed by the newest generation of common rail systems. It features a high pressure pump and an injection rail for each cylinder bank. A high injection pressure of up to 2,000 bar (29,001 psi) – which equals the weight of a SUV within an area the size of a fingernail – permits an even finer atomization of the fuel, which provides better mixture preparation and more efficient combustion.

The injectors in the common rail system employ the piezo effect, in which an electric voltage is applied to a special ceramic, altering its crystal structures. This results in a certain amount of expansion, which is transferred directly to the injectors.

Multiple injection events per cycle

With piezo injectors, the number of injection processes per cycle can be varied and optimized almost at will. The Audi TDI development engineers have opted for up to five injection processes for the 3.0 V6. In the lower speed range, additional double pilot injection occurs in addition to the main injection process; in the medium range there's single pilot injection. Simple post injection occurs up to around 2,500 rpm and under partial load. This strategy reduces emissions and ensures a smoother combustion process, which primarily benefits the engine's acoustic behavior. The 3.0 TDI produces a quiet, cultivated and harmonious sound.

The V6 TDI features a turbocharger with variable turbine geometry on board. Its vanes are guided by an electric servo motor – this improves propulsive power at low rpms. Two large intercoolers reduce the temperature of the compressed air in order to increase the overall efficiency.

The range: over 600 miles

The Audi Q7 3.0 TDI delivers powerful driving performance: the speedometer needle takes just 8.4 seconds to go from zero to 60 mph. The big SUV reaches a top speed of 130 mph, or 134 mph when equipped with adaptive air suspension. The V6 diesel delivers 25 miles per gallon – providing a fuel range of more than 600 miles from a full tank that holds 26 gallons of fuel.

The Audi A5 3.0 TDI

The V6 TDI engine is so packed with power that it also allows Audi’s dynamic A5 Coupe to perform impressively. With a sprint speed from zero to 60 mph in just 5.9 seconds and a top speed of 155 mph, the Audi A5 3.0 TDI quattro is one of the sportiest specimens in its class.

The pressure at low and moderate rpms and the propulsive force in the upper range can only be described as impressive. Considering its potential, the 3.0 TDI is astonishingly economical – its average mileage amounts to 37 miles per gallon.

The Audi Q7 4.2 TDI

With 326 hp and 560 lb/ft of torque over a range from 1,800 to 2,500 rpms, the Q7 4.2 TDI was the world's most powerful eight cylinder diesel engine made for a passenger car at its market introduction. One test drive is all it takes to show what makes the TDI from Audi a smart choice as a sports engine. Just a gentle touch on the accelerator is all it takes to propel the large SUV forward. It can sprint from a standstill to 60 mph in just 6.3 seconds – faster than many sports cars – but it uses much less fuel than a comparable gasoline engine, delivering an average of 24 miles per gallon. Its top speed in the U.S. is limited electronically to 130 mph; in Europe the Q7 reaches 147 mph.

At any rpm and in any driving situation, the most powerful V8 diesel engine in the SUV segment provides superior propulsive power. The Audi Q7’s poised nature and highly cultivated ride make it a touring car you can comfortably cover long distances in with confidence and ease.

A typical V8: 90 degree cylinder angle

The cylinder angle of the V8 TDI is a traditional 90 degrees, and the length measures just 520 millimeters. As with the V6, the crankcase is constructed of high tech vermicular graphite cast iron; this is what allows the engine to weigh a mere 257 kilograms. The crankshaft is forged from chrome molybdenum alloy steel and the pistons are cast aluminum. UV laser treatment of the cylinder bore reduces oil consumption to a minimum.

The large TDI has a chain drive for its four camshafts and auxiliaries. Cam followers actuate the 32 valves in the aluminum cylinder head. Electronically operated flaps in the intake manifold modify incoming air as needed into a controlled swirl. Both turbochargers operate with electrically adjustable turbine geometry. They provide vigorous torque even at low rpms and create up to 1.5 bar of relative boost pressure. Two large intercoolers reduce the temperature of the compressed air and ensure the high volumetric efficiency of the cylinders.

Small and compact piezo inline injectors are integrated into the highly modern common rail injection system. They can achieve up to five injection processes per cycle. These, combined with the rigid engine construction and especially quiet valve gear, contribute decisively to the cultivated ride of the high tech diesel. The maximum injection pressure of 2,000 bar results in a fine atomization of the fuel as it is discharged from the eight-hole jets. This provides ideal mixture preparation and combustion, which in turn produces high efficiency.

The Audi Q7 V12 TDI

The Audi Q7 V12 TDI represents a new chapter in the history of diesel engines. The world’s first V12 diesel engine for a production automobile will be introduced initially to the European market during the course of this year, powering the big, high performance SUV with tremendous poise and composure. On command, the six liter engine catapults the Q7 from zero to 60 mph in 5.3 seconds with its 500 hp capacity and 737 lb/ft of torque – just like a top flight sports car. Propulsion is electronically limited to 155 mph.

The 12 cylinder diesel also displays impressive consumption figures. Considering the power of the engine, the vehicle’s average 20 miles per gallon is striking. The six liter TDI significantly outperforms its gasoline powered competitors in the field of high performance SUVs.

Highly cultivated engine sound

The highly cultivated operation of the V12 TDI is also fascinating – the sound is subtle, and when subjected to engine load it assumes a musical, voluminous tone. The six liter engine is also a member of Audi’s V family of engines. Instead of the usual 90 degrees, however, the cylinder angle measures 60 degrees – ideal for a

V12, since this construction prevents the occurrence of undesirable free inertial or internal forces.

The crankcase also contributes to its high rigidity and quiet running. Made from cast iron with vermicular graphite, it’s about 15 percent lighter than conventional cast iron. The crankshaft is mounted with a rigid main bearing bridge made of nodular graphite iron. The forged connecting rods are cracked to enhance their strength.

The cylinder heads consist of three parts, and low friction cam followers actuate the valves. Flaps in the intake ducts produce a swirl into the intake air, which promotes the combustion process. The common rail system builds up pressure of up to 2,000 bar – a new optimum value in TDI technology. The eight-hole injectors work according to the piezo principle – they work with five injections per cycle.
Two turbochargers are located externally on the engine block; they supply one cylinder bank each. Thanks to their adjustable vane geometry, they respond quickly and achieve high efficiency; they generate a maximum of 1.6 bar of relative boost pressure. Two large intercoolers reduce the temperature of the compressed air.

The Audi R8 V12 TDI

The V12 TDI unleashes the kind of incredible power that also makes it a suitable engine for a supercar – Audi unveiled a concept car based on the R8 at the Detroit Auto show earlier this year. Again – in a mid engine configuration – the engine produces a whopping 500 hp and 737 lb/ft of torque, which is reached at only 1,750 rpm. In terms of design, the Audi R8 V12 TDI is reminiscent of the Audi R10, the two time winner of the Le Mans 24 hour race, and the engines are also close relatives.

The V12 TDI also catapults the Audi R8 into the supercar league when it comes to driving performance. The sprint from zero to 60 mph takes just 4.1 seconds, and can reach a top speed of 190 mph. The engine sound is also a thrill – while it’s characterized by the quiet running typical of this engine type, it resounds with full bodied vigor. With its aggressive, goosebump raising overtones, the 12 cylinder diesel doesn’t try to hide its power by any means.

The world’s cleanest diesel:
The 3.0 TDI with ultra low emission system

Audi is raising diesel technology to a new level. In early 2009, the brand with the four rings will introduce the 3.0 TDI with ultra low emission system to the U.S. market. The world's cleanest diesel engine will debut in the Audi Q7 and Audi A4.

The ultra low emission system combines a complete package of innovative features, including a new common rail system with piezo injectors that operate with an injection pressure of 2,000 bar (29,001 psi), highly efficient exhaust gas recirculation and further optimized turbocharging, all of which reduces engine emissions. Pressure sensors in the combustion chamber represent just one of Audi's worldwide innovations – these sensors allow even more precise control of combustion processes.

Another technical breakthrough is the cleaning system in the exhaust gas system, which reduces nitrous oxide emissions by up to 90 percent. AdBlue, a liquid, 32.5 percent urea solution, which is sprayed in small amounts into the DeNox catalytic converter, aids this process. In the hot exhaust, the solution breaks down into ammonia, which the nitrous oxide then splits into nitrogen and hydrogen.

The complete system consists of the catalytic converter, a dosing module and the AdBlue tank. The solution has a freezing point of 12° Fahrenheit, which is why the tank system is heated in extremely cold conditions. The control sensors are also highly elaborate: two NOx sensors measure the concentration of nitrous oxide, while all functions are monitored with pressure and temperature sensors.

Total convenience for Audi customers

The AdBlue container is filled via the fuel tank flap, just like the fuel tank. Its reservoir is divided into two containers – the active and the passive tank. The biodegradable AdBlue solution is refilled at the workshop at each service appointment, without requiring the customer to concern himself. Because of its low consumption, Audi ensures that the supply is sufficient to cover service intervals. The efficiency of the system is ensured throughout the lifecycle of the vehicle.

Thanks to its extremely low emissions, Audi can deploy its clean diesel direct injection system worldwide, even in the U.S. states of California, Massachusetts, Maine, New York and Vermont, which have extremely stringent emission limits. Starting in 2010, the brand with the four rings will offer the new technology in additional vehicle and performance classes.

Audi TDI – at the top for the past two decades

Audi is the pioneer in turbocharged diesel engines with direct injection – since 1989 the company has built and sold more than 4.5 million cars with TDI engines. From the very start, the initials TDI began to develop into a synonym for superior propulsive power and a maximum efficiency; the technology has advanced to become a trend setter for the entire automotive industry.

No other drive system has yet been able to beat the turbocharged diesel direct injection engine when it comes to power combined with low consumption. When driven by consumers, consumption by TDI cars is up to 35 percent lower than comparable cars equipped with the gasoline engines typical in North America.

The engine that Audi presented in late summer of 1989 at the Frankfurt motor show: The five cylinder turbodiesel, installed in the Audi 100, featured 2.5 liters of displacement for 120 hp and 195 lb/ft of torque. It was the world’s first diesel passenger car with direct injection and fully electronic engine management – the first TDI. With its brawny power, the five cylinder engine, that went into regular production in what was then the fourth generation of new Audi 100s, set a new standard in the diesel sector. Since then, Audi has extended this technological advantage with continuous, new phases of development.

Half of all Audis feature TDI

For the past 19 years, the brand with the four rings has been using its accumulated innovative capabilities to repeatedly extend the limits of possibility. The TDI engines have had a decisive impact on the emergence of Audi as a maker of premium sports cars; today, half of all Audis that are sold around the world have a diesel engine under the hood. The TDI engines have achieved an unprecedented triumph – and are continuing on at full throttle.

In Europe, the success of the TDI principle has been unmatched – today, more than half of all new cars sold in Western Europe are equipped with a modern diesel engine, and in some countries the proportion of diesels has reached 80 percent. This makes the direct injection diesel engine the world's most successful efficiency technology.

The TDI – the superior principle

The TDI engines from Audi are superior engines that feature commanding performance and dynamic power. The 221 hp of the three liter TDI that powers various Audi models, for example, provides about 80 hp of output per liter of displacement – a level that just a few years ago was reserved for the sports car segment. Thanks to their extremely low consumption levels and their proliferation, especially in Europe, TDI engines have become the most successful efficiency technology in the world. When driven under realistic, mixed driving conditions, TDI cars generally also beat comparable models with hybrid drives.

TDI engines feature high propulsive power

The greatest strength of all Audi diesel engines is their tremendous torque. Their propulsive power makes these diesel engines clearly superior to any comparable gasoline engine. This mighty power is also available at extremely low revs – just a little over idle speed – as a smooth but insistently applied impulse that requires only the slightest pressure on the accelerator.

In sharp contrast to many stressed, high revving gasoline engines, the propulsive power is always available when it’s needed – and this contributes to a highly composed, relaxed style of driving. In the style of the classic American small block, the three liter V6 produces 406 lb/ft of torque at the crankshaft, which is available at just 1,750 rpm. The diesel engine produces 137 lb/ft per liter of displacement – a level that far surpasses that of the gasoline engine.

TDI engines are efficient and economical

Diesel engines make more efficient use of the energy in their fuels than do gasoline engines. This fundamental principle of physics has been refined through many solutions that Audi has played a major role in developing – including the four-valve technology that ensures optimum filling of cylinders in every situation and the principle of variable vane geometry for turbochargers.

The outstanding efficiency of Audi’s TDI engines benefits the driver of a Q7 3.0 TDI both when it comes to saving money and when it comes to covering long distances: with its 26 gallon tank, the car can cover more than 600 miles on a single fill up – saving the cost, time and annoyance of extra stops at the filling station.

TDI engines are quiet and comfortable

The modern direct injection diesel engines from Audi are hardly perceptible to the ears of their passengers – their operation is virtually indistinguishable from that of a gasoline engine. This is thanks in part to the extensive development efforts of Audi’s engineers. Selective ribbing on the engine blocks inhibits vibrations during operation; all pathways on the engine mounts and car body that could transmit vibrations to the interior have been eliminated.

The common rail technology is the source of another major advance. With it, the multiple injections per cycle capability can generally be freely selected in the control unit. The pilot injections, which are widely spaced from the main injection, provide a gradual increase in pressure that makes the combustion process smoother. The innovative piezo injectors used by Audi further reinforce this effect with their extremely fast and precise switching – with these injectors, the hard “knocking” and metallic rattling at partial load is history.

The TDI – perennial winner in motor sports

At the beginning, the drivers couldn’t believe their ears – long time professionals like Frank Biela (Germany) and Tom Kristensen (Denmark) had to completely change their driving habits. Up to then, they had acclimatized themselves to the engine noise in their open sports cars – and now, from a certain speed onward, it could no longer be heard. That’s how quietly the V12 TDI runs in the new Audi R10.

With the 12 cylinder diesel, Audi had written a completely new chapter in the history of motor sports. The 5.5 liter TDI, which was created according to the rules applied at the Le Mans 24 hour race, is a superior racing engine. Its torque – at more than 800 lb/ft. – is vastly superior to any gasoline engine. At the engine’s rated speed it puts out more than 650 hp – enough for a top speed of over 200 mph, depending on transmission.

The V12 TDI’s low fuel consumption is another strength. Compared to its predecessors – the already highly efficient R8 with gasoline direct injection, the R10 in Le Mans consumed about 10 percent less fuel, although the long, straight stretches along the Sarthe and 75 percent full load operation only partially showcased the advantages of the diesel engine.

Fewer fill ups equal victory

The long fuel range, which means fewer stops for refueling, was the key to victory at the classic 24 hour race. Biela and teammates Emanuele Pirro (Italy) and Marco Werner (Germany) only had to refuel their No. 8 car 27 times during the race. They completed 380 laps – or 2,003 miles – at an average speed of 133.9 mph.

Fresh from their victory at Le Mans, Audi then went on to the American Le Mans series and achieved something no carmaker had previously done – the R10 won all eight races it entered during the course of the season. The string of victories stretched throughout the United States. It began in March with the 12 hour race in Sebring, Florida, and ended in October in Laguna Seca, California. Allan McNish (Scotland) and Dindo Capello (Italy) were declared overall winners in the big LMP1 category long before the season ended.

The 2006 Race Engine of the Year

A jury from the British trade magazine, “Race Engine Technology,” selected the V12 TDI from the Audi R10 as the “2006 Race Engine of the Year” and the “Alternative Race Engine of the Year”. For its design engineer, Ulrich Baretzky, Audi Sport’s Head of Engine Technology, and Dr. Wolfgang Ullrich, Head of Audi Motorsport, it stands as the perfect example of close cooperation between motor sports and regular production.

“We were able to rely on the know how and the engine test rigs of our colleagues from series production development,” Ullrich said. At the same time, the exchange of information also functioned in the opposite direction. Technical highlights such as the aluminum crankcase that can cope with extremely high ignition pressures lend important new impetus to production development.

Audi had carried out comparable technology transfer processes as far back as the late 1980s. At that time the touring cars from Ingolstadt – with their gasoline turbo engines that at times reached more than 700 hp – dominated the TransAm and the IMSA races. As was true 20 years ago, today’s motor sports continue to provide crucial advances to the development of high volume production cars.

New victories in Le Mans and in the ALMS series

Biela, Pirro and Werner also managed to prevail at the 2007 Le Mans 24 hour race with the Audi R10, despite the fact that race organizers restricted the fuel tank size. Under difficult weather conditions, the trio completed the 369 laps at an average 130.0 mph. The diesel racing car with the four rings also stormed from one victory to the next in the American Le Mans series. The car secured its 20th victory in a row in the LM P1 class at the street circuit in Detroit, handing Audi its eighth straight title as a manufacturer.

Posted in | Submitted by deviantspeed on Fri, 2008-04-04 20:26.
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