|
Price |
|
-- |
Production |
|
-- |
|
Engine |
6
liter TDI Diesel V12 |
Weight |
-- |
|
Aspiration |
twin
turbochargers |
Torque |
738
lb-ft @ 1750 - 3000 rpm |
|
HP |
500
hp |
HP/Weight |
-- |
|
HP/Liter |
120
hp per liter |
1/4 mile |
-- |
|
0-62 mph |
4.2
seconds |
Top Speed |
over
186 mph |
(from Audi Press
Release) Audi R8 V12 TDI concept
Outstanding Torque for the Top
Class Audi R8 V12 TDI concept
Audi is presenting a
revolution in the top class at the Detroit Auto Show 2008 the
first 12-cylinder diesel engine in a high-performance roadgoing
sports car. The V12 TDI with a displacement of six liters powers a
concept car based on the Audi R8. This unit generates a huge 500 hp
and 1,000 Newton-meters (737.56 lb-ft) of torque. Audi is writing a
new chapter in diesel technology with this power unit. Equipped with
the expertise that Audi has built up through its motor sport
activities, the R8 V12 TDI in matt "Grace Silver" embodies superb
road handling, pioneering technology and fascinating design.
The V12 TDI is closely
related to the engine in the Audi R10, the two-time Le Mans winner
so it catapults the Audi R8 into supercar terrain concerning
performance too. It sprints from zero to 100 km/h (62.14 mph) in
just 4.2 seconds and its top speed is well over 300 km/h (186.41
mph). The peak torque, reached at only 1,750 rpm, paves the way for
effortless acceleration that is unrivaled even at this level.
The new V12 TDI belongs
to Audi's family of V engines but has the ideal included angle for
this engine type of 60 degrees between cylinder banks. Its
highlights include the new chain drive layout that includes the two
newly developed high-pressure pumps for the common rail injection
system.
Its sound is as thrilling as you'd expect in a sports car of this
caliber. For all the subtle smoothness that typifies this design
principle, the twelve-cylinder unit is full-bodied and equipped with
energetic overtones that make no secret of its performance
potential.
The Genes of the Winner
Thanks to their high
performance and pulling power, all Audi TDI engines are
ultra-dynamic sources of power. The brand has often enough
demonstrated its sporty character in its production cars, especially
the six- and eight-cylinder 3.0 TDI and 4.2 TDI. Audi has also been
writing a new chapter in its success story on the racetrack since
2006. The diesel engine in the R10 sports prototype won its very
first endurance race at Sebring, Florida, when it was pitted against
an entire field of gasoline-engined challengers. But its most
crucial victories were surely in 2006 and 2007 in the 24 Hours of Le
Mans, when it simply outclassed the international elite.
The V12 TDI race engine
in the R10 produces over 650 hp from a displacement of 5.5 liters,
giving it the potential for a top speed as high as 330 km/h (205.05
mph) depending on the gear ratios. Its power and sturdiness
immediately impressed both fans and experts, who were impressed by
its restrained noise level. Unusual for a race engine, this powerful
Audi diesel makes barely more than a whisper.
Long traditions of motor
racing and production technology complement each other at Audi. The
FSI engine of the R10's predecessor, the R8, captured five wins at
Le Mans with a direct gasoline injection system. Audi is also
looking to maximize the advantage by using the race-tested FSI
principle in its production models. The latest examples of this are
the V8 with high-revving concept in the RS 4 and the production
version of the Audi R8.
The Drivetrain
The roadgoing version of
the new V12 TDI is built at the Gyr plant, in Hungary. And the R8
V12 TDI still has a massive 500 hp on tap. In developing the
six-liter engine, it was a clear priority to integrate it into the
current family of Audi V engines, of which many thousands of
versions with 6, 8 and 10 cylinders have already been built both
gasoline and TDI.
Audi's engineers were in
an ideal position to use their experience building the racing engine
to develop the road version. Like the other power units in this
range, the distance between cylinder bore axes on the V12 TDI is 90
mm (3.54 in.). Yet its included angle is 60 degrees, not 90 degrees.
This means no free inertial forces or mass moments of inertia can
occur with the V12. The results are refined in every respect.
The 83.0 mm (3.27 in.)
bore and 91.4 mm (3.60 in.) stroke produce a total displacement of
5,934 cc just like the 3.0 TDI. At only 684 mm (26.93 in.) long,
this large diesel engine is very compact and just 166 mm (6.54 in.)
longer than the V8 TDI. This compact length is key to accommodating
the V12 in the midengined Audi R8.
The V12 TDI crankcase is
made from gray cast iron with vermicular graphite a high-tech
material referred to as GJV-450 that is already used on the V6 and
V8 TDI engines. GJV-450, made by a patented casting process, is
about 40 percent more rigid and 100 percent more fatigue-resistant
than gray cast iron. This enabled the developers to make its walls
thinner, cutting its weight by around 15 percent compared with
conventional gray cast iron.
The two cylinder heads
are each made from three main elements. These are a base section
made from a high-strength aluminum alloy incorporating the intake
and exhaust ports, an oil-bearing upper section, and a reinforcing
ladder frame supporting the two camshafts.
The valves are actuated
by low-friction roller cam followers; the compression ratio is
16.0:1. Map-controlled swirl variation of the combustion air has
been adopted from the V6 and V8 TDI engines. This produces
permanently optimized swirl concerning both emissions and high
performance.
Ultramodern Injection Technology
As is the case in the
Audi V engines, the no-maintenance chain drive is mounted at the
back of the engine, where it occupies little space. Its layout has
changed on the new V12 TDI. The camshafts' sprocket engages in an
intermediate gear via which two Simplex chains drive the camshafts.
Two more chains drive the oil pump and the two high-pressure pumps
actuate the common rail injection system.
The two new dual-piston
high-pressure pumps form part of the common rail injection system
supplied by specialty manufacturer Bosch. The two pumps build up a
pressure of up to 2,000 bar in the rails. The piezo injectors with
eight-hole nozzles have also been fundamentally revised.
The high pressure
distributes the mixture optimally throughout the combustion chamber.
The result is that the ignition process is faster, more homogeneous
and more acoustically refined. The more efficient combustion process
also increases power output, cuts consumption and reduces pollutant
emissions.
The current generation
of so-called inline injectors makes effective use of the piezo
effect: piezo crystals expand in a fraction of a millisecond when an
electrical voltage is applied. The number of injection processes per
operating cycle can be varied across a wide range thanks to piezo
technology reaching as many as five fuel injection operations in
the case of the V12 TDI.
As well as the main
injection, pilot and post injections are possible. Pilot injections
tone down the acoustic harshness of the combustion process. Retarded
post injections are designed specifically to increase the
temperature of the exhaust gas, promoting regeneration of the two
standard particulate filters.
The two turbochargers
are located on the outside of the engine's V, each of them supplying
one bank of cylinders. Thanks to their variable turbine geometry,
the full flow of exhaust gas always passes through the turbine, so
the chargers respond slickly even at low engine speeds and
operate very efficiently.
The two turbochargers,
which generate up to 2.6 bar of boost pressure, play a crucial role
in producing the huge torque of 1,000 Nm (737.56 lb-ft) that the V12
TDI maintains from 1,750 rpm to 3,000 rpm. In developing 368 kW (500
hp), the diesel achieves a specific output of 62.0 kW (84.3 hp) per
liter displacement.
Two large intercoolers
reduce the temperature of the compressed air. The V12 has a
twin-pipe exhaust system with two particulate filters. The intake
system is similar in structure with one air cleaner per cylinder
bank, with an airflow meter behind it. Two control units, sharing
the workload in a master/slave principle, manage events in the
engine.
The Audi R8 V12 TDI
concept already fulfills the Euro 6 emissions standard that is
likely to take effect in 2014 and calls for sharply reduced nitrogen
oxides. By also designing in ultra-precise fuel metering by the
common rail system, Audi's engineers have made full use of current
clean diesel technology.
The heart of the system
is a special catalytic converter downstream of the oxidizing
catalyst and the particulate filter. The second component in the
system is an additional tank containing an aqueous urea solution.
Small quantities of the solution, known as "AdBlue," are injected
into the exhaust system. The hot exhaust gases break the solution
down to form ammonia that splits the nitric oxides into nitrogen and
water. The system remains effective for the entire service life of
the vehicle.
The dynamic character of
a sports car depends not just on its performance and torque; the
transmission ratios have to be right too. In keeping with the
character of a high-performance sports car with unbeatable torque
potential, the transmission in the R8 V12 TDI has six manually
operated gears.
The manual transmission
is very compact in design. Together with the small-diameter
double-plate clutch, this means it can be installed low down. The
manual transmission has very short shift travel and utterly precise
guiding of the shifter into the open gear lever gate. It is made
from polished aluminum, has an agreeable feel and exquisite sports
car looks.
Such a high-performance
Audi also has quattro permanent all-wheel drive. In the case of this
mid-engine sports car, power is distributed variably between the
front and rear wheels from a starting ratio of 40:60 to optimize the
handling.
The Design
The R8 V12 TDI concept
with matt "Grace Silver" bodywork looks even wider and more resolute
than the core model. It shows its potential through its muscular
proportions, accentuated wheel arches and even larger air apertures.
The rhombus-pattern cover on the air inlets and outlets is the
hallmark of Audi's sporty top models and a familiar feature of the
current RS generation.
Typical of the side view
of the R8 is the sideblade. Much wider in the bottom third, it
visually accentuates the engine's position as well as acting as an
enlarged air deflector.
The continuous aluminum
spoiler lip that connects the front and rear diffusers with side air
baffles below the enlarged sills also pays tribute to this version's
highly developed dynamic talents.
And yet the R8 is
unmistakable for its powerful, elegant basic proportions. The
selective but always precise use of lines is another typical Audi
characteristic, as is the curved arc of the roof. One new aspect is
the glass roof of the passenger compartment with two large
transparent sections. These, together with the glazed engine
compartment behind, create a radically new formal element. The
unmistakable NACA duct in the middle of the roof is a functional
detail that is normally reserved for racing cars. Its ingenious
shape accelerates the air drawn in here for the two cylinder banks
of the V12 TDI engine.
The V12 TDI is displayed
as the beating heart of this sports car, like a work of art inside a
large showcase. Its look, underscored by the air deflectors located
beneath the restyled rear glass lid, differs clearly from its
production counterpart. The engine can even be seen after dark, when
white light-emitting diodes illuminate the engine compartment as
on the production R8 version. This "showroom" can additionally be
fully lined in genuine carbon fiber, for a particularly exclusive
look.
The continuous line
running from the front apron across the wheel arches and flanks to
the tail end, then back down the other side, is one of the latest
design hallmarks of the Audi brand. This "loop" naturally
encompasses the air apertures, the headlights and the taillights.
Unmistakable Face by Day and Night
The passion expressed
through the elaborate design of the lights is another typical Audi
trait. Nor is anyone likely to overlook this Audi sports car from
behind: the LED taillights have a three-dimensional look that cant
be missed.
But the absolute
highlight is the all-LED headlights of the study vehicle. With their
lenses and reflectors, not only do these innovative light sources
have a ground-breaking appearance, they also have an enormous
functional advantage: LED light, with its color temperature of 6,000
Kelvin, resembles daylight much more closely than xenon or even
halogen light. Better light means the driver will have much less
fatigue when driving at night.
Ergonomic and Elegant
The interior's design is
as sporty and exclusive as the exterior: the characteristic element
here is the monoposto an expansive arc running around the steering
wheel and instruments, connecting the driver to the car. The
interior consequently picks up on the dynamism of the R8 V12 TDI
concept and gives it tactile expression in a form that is accessible
the moment you climb in.
The three-spoke sport
steering wheel of course remains the focal point of the car's
controls. With a diameter of 365 mm (14.37 in.), it is both sportily
compact and ergonomic in shape. The steering wheel rim has a flat
lower edge. This is a further aspect of the auto racing feel in the
Audi R8 V12 TDI, but one that also brings major functional benefits,
facilitating entry and exit for the driver. The steering wheel is
covered in fine Valcona leather, with a diecast magnesium core
providing strength.
The start/stop button
for the engine and the Drive Select switch with the Dynamic/
Sport/Race settings are arranged on the steering wheel. The latter
controls the engine and transmission electronics as well as the
magnetic ride dampeners in each of three different modes.
In Race mode, the
instrument lighting changes from white to red. The navigation system
shows a combined display with lap timer and navigation information
for the racetrack being driven. Or supplementary information such as
centrifugal force and boost pressure can be called up.
Concentrating on the
essentials was the priority in the ergonomic arrangement of all Audi
R8 versions. The most important consideration particularly for
high-speed driving is short reach distances for all controls, to
keep the time that the driver has only one hand on the steering
wheel to a bare minimum. In typical Audi style the monitor is well
within the field of view, and the elements of the MMI operating
system are located directly below it.
Compared with the
production version, the R8 V12 TDI concept's interior has much
larger aluminum applications, especially around the center console.
The many carbon fiber elements give the interior a decidedly sporty
feel.
The R8's exceptional
everyday practicality for a sports car is maintained in the study
vehicle's spaciousness, even though the longer engine takes up more
room. The two occupants have the generous wheelbase of 2.65 meters
(8.69 ft.) to thank for the interior comfort. This means the driver
and passenger will always be able to find their perfect seated
position, whatever their build. The view is also very good for a
mid-engine vehicle. Narrow A-posts optimize the field of view to the
front and sides.
Light but Highly Rigid Body
The body of a sports car
needs to be particularly light and rigid. Low weight permits
superior road performance, and rigidity is the crucial starting
point for an agile driving feel allied to high precision. The Audi
Space Frame body, made from aluminum, provides the ideal basis for
this.
Audi has more expertise
than any other manufacturer worldwide in the design and production
of vehicles based on aluminum technology, and has channeled its
accumulated know-how into this area.
The entire bodyshell of
the study car weighs just 210 kilograms (462.97 lbs.). In ASF
technology, the body's supporting structure is made of extruded
aluminum sections and die-castings. Aluminum panels are incorporated
into this skeleton to form a positive connection and perform a
load-bearing role. Each individual component of the ASF space frame
is optimized for its specific task by the use of widely differing
shapes and cross-sections, combining maximum stability with minimal
weight. It adds up to a car thats particularly light and rigid, an
outcome that can be felt in the R8s ultra-precise driving feel.
The aerodynamics experts
at Audi have done their work so thoroughly on the study car that, as
an added benefit of its elegant shape, the body actually generates
downforce unlike many other sports cars. This aids directional
stability at high speeds. It is achieved partly by means of an
extending rear spoiler that is much larger than on the production
version, and also thanks to the fully clad diffuser underbody.
Two large-format
diffuser apertures in the rear bumper demonstrate just how much
aerodynamics dictate the shape of the study vehicle. The tailpipes
of the exhaust system are located in pairs on the right and left
above the diffuser apertures. The add-on, automatically extended
rear spoiler also interacts with the air as it flows around the car.
The extra downforce it provides increases the efficiency of the air
intake generated by the aerodynamic design of the underbody and
diffusers. At low speeds, the rear spoiler returns to its initial
position.
Chassis
The precision chassis of
the Audi R8 V12 TDI concept remains supremely in control of the
sporty performance, but is capable of assuring relaxed driving
pleasure over long distances too. The sports car is spontaneous and
agile at obeying steering movements, always demonstrating
exceptionally good driving safety. The suspension, with double
wishbones at both the front and rear, is optimized for a neutral
self-steering response and maximum ease of control.
The study car, too, has
the innovative dampening technology known as Audi magnetic ride.
This adapts the chassis characteristic to the profile of the road
and the driver's style within milliseconds.
Ceramic Brakes with Extreme
Reserves
A generously dimensioned
brake system supplies the necessary braking force. It applies a
total of 24 pistons to the four brake disks, combining excellent
performance with minimal weight and high durability. The disks are
made from carbon fiber reinforced ceramic, a material that has
repeatedly proven its worth in the aviation and aerospace sectors.
The basis is very hard, frictionally resistant silicon carbide, with
its diamond-like crystalline structure. Embedded in it are
high-strength carbon fibers that absorb the stresses occurring in
the material. The intricate geometry of cooling ducts in the
ventilated disks prevents extremely high temperatures. The ceramic
brake disk ring is bolted by 10 spring-loaded elements to a
stainless steel central element that acts as the connection with the
wheel's hub.
The ceramic brakes are
identifiable at a glance by the special red, six-piston monobloc
aluminum calipers and the fixed calipers at the rear. The advantages
of the ceramic brakes include a further reduction in weight of
around 20 kilograms (44.09 lbs.), which in this case improves the
handling characteristics and comfort. The high abrasion resistance
permits an operating life of up to 300,000 kilometers (186,411
miles). Their key strength, however, is their ability to withstand
very high loads. Even on the racetrack, for example, the ceramic
brakes always maintain their full reserve performance.
Vorsprung durch Technik: Diesel
Milestones from Audi
Audi has reached another
milestone in diesel technology with the new V12 TDI. The brand with
the four rings has been performing vital pioneering work in this
area for the past three decades. Audi premiered the world's first
five-cylinder diesel engine in the Audi 100 in 1978. The first TDI
auto engine made its debut in 1989 in the successor model. The 2.5
liter five-cylinder power unit developed 88 kW (120 hp) and 261 Nm,
catapulting diesel driving into an entirely new dimension.
This was followed in
1994 by a development version generating 103 kW (140 hp). This
engine was optionally available with all-wheel drive the first TDI
quattro model. A new four-cylinder diesel appeared at that time in
the Audi 100 and Audi 80, the 1.9 TDI developing 66 kW (90 hp) that
has now become legendary.
At the end of 1995 the
output of this four-cylinder unit rose to 85 kW (115 hp) with the
advent of pump-injector fuel injection. Slightly more than one year
later, at the start of 1997, the world's first 2.5 V6 TDI appeared.
With four valves per
cylinder, it achieved an output of 110 kW (150 hp), and its top
speed of 220 km/h (136.70 mph) made the Audi A8 the fastest
production diesel on the market. The first eight-cylinder TDI
followed in 1999 a V8 engine with a 3.3 liter capacity. The 3.0
TDI made its debut early in 2004 as the first V6 diesel with inline
piezo injectors in the common rail system.
The 4.2 liter TDI
launched in the A8 in 2005 is currently at the vanguard of Audi's
TDI range. One in three A8 buyers in Germany chose this V8 engine.
The next logical step was to make the V8 TDI available in the Audi
Q7 in summer 2007.
With extremely clean,
ultra-low emission technology, Audi is continuing its tradition of
leadership in diesel engine technology. In 1989 it was the
Ingolstadt brand that developed direct injection technology. Since
then the diesel engine has become around 30 percent more efficient.
The Euro 4 European
emission standard has reduced particulate emissions for cars by 93
percent. Long before it came into force, Audi had models on the
market that met this standard, even without a particulate filter.
And the brand will be offering the world's cleanest diesel engines
in production vehicles in 2008. The TDI engines with the ultra-low
emission system will be the first in the world to meet the
forthcoming EU 6 emission standard as well as the toughest known
statutory limits that apply in the U.S.
