motorsport and production

7/28/2019 Motorsport and Production

http://slidepdf.com/reader/full/motorsport-and-production 1/68

MediaInfo

Motorsport and ProductionAudi Le Mans Prototypes 1999–2013

VTGCFRPAerodynamics

24 Hours

WECLe Mans

Efficiency

ultra lightweight design

e-tron quattro



3

Editorial by Wolfgang Dürheimer

Comparison between Audi sports

prototypes

Win rate

ultra-lightweight design

Assistance systems

Engine technology

Aerodynamics

Interview with Dr. Wolfgang Ullrich

DTM–LMP comparison

Number facts

Audi R8 LMS ultra and Audi R8

Technology transfer

Masthead

4

6

14

20

26

34

40

48

52

56

58

64

66

Contents



4

Editorial



5

Wolfgang DürheimerAudi has been competing at Le Mans since 1999. This

year, we will again be challenged to continue the unrivaled string of successesachieved in recent years and to clinch the twelfth victory in the world’s mostfamous endurance race.

We are often asked

what is left for Audi to

prove at Le Mans, hav-

ing achieved eleven

victories there to date. Does the technology

transfer from motorsport to production

really exist? At first glance, Le Mans proto-

types such as the Audi R18 e-tron quattro

seem to have clearly less of a kinship with

our production cars than an Audi RS 5 DTM

or an R8 LMS ultra, for example. The latest issue of our

MediaInfo magazine ‘Motorsport and Production’ invites

you to discover that appearances are deceptive though.

It will show you that Le Mans, right in

the spirit of this tradition-steeped race, is the toughest

test lab for new developments for us. Did you know, for

instance, that our engineers have reduced fuel consump-

tion by more than 20 percent since 2006 when we started

to use TDI technology? Or that the safety cell – the CFRP

monocoque – now weighs only half of what it did in 1999?

Today, assistance systems support our

race drivers. This, too, is leading-edge technology, whichis particularly relevant for Audi’s current and future auto-

mobiles. Our race drivers are looking forward with the LED

light beam, which has a range of more than 800 meters,

emitted by Matrix-Beam headlights. This is the future of

lighting technology, in production cars as well.

At the world’s toughest 24-hour race,

Audi, with a hybrid race car, is testing tomorrow’s auto-

motive technology today. I wish you a gripping race at

Le Mans and a fascinating season with thrilling motor-

sport in the F IA World Endurance Championship (WEC).

Wolfgang Dürheimer

Member of the Board of Management of AUDI AG,

Technical Development



6

Lookingbeneath

the skin



7

Comparison between Audi sports prototypes14 years have passed since Audi competed at Le Mans

for the first time. The first LMP sports car in 1999 was an Audi R8R. Today,the brand relies on the Audi R18 e-tron quattro. There is a world of differencebetween these two models. Dr. Martin Mühlmeier, Head of Technology at AudiSport, has accompanied the development of the sports prototypes back then

and today. A look beneath the carbon fiber skin of the race cars brings backmemories of exciting developments in all areas.



8

Dr. Martin Mühlmeier looks back on 14 yearsof sports car development

The arrival of TDIpower in 2006marked a change of the entire concept

Not even the mathemati-

cal calculation methods

have remained the

same,” says Dr. Martin

Mühlmeier, Head of Technology at Audi Sport, recalling

the transition period shortly before the start of the new

millennium. Until 1998, all Audi race cars were still

based on steel structures. Except for the 1989 Audi 90

IMSA GTO, all rally models and touring cars were directly

derived from production models. “The 1999 R8R was our

first concept with a stressed CFRP structure. This mate-

rial exhibits a completely different behavior. While

metallic materials bend or break in a crash, carbon fiber

collapses. Consequently, the calculation methods used

here are totally different.”

In the early phase, Dallara assisted with

their experience. The Italian company acquired its exper-

tise over many years as a constructor of ‘monoposti’

(open-wheelers) and sports prototypes. “Audi Sport

Audi achieved

major progress,

from the steel roll

bar to the closed

CFRP cell.

subsequently entered the field of CFRP on its own,”

Dr. Mühlmeier goes on to explain. “We implemented this

know-how, strengthened our resources by recruiting

highly skilled personnel and developed proprietary calcu-

lation methods. This soon made it possible for us to cal-

culate structures, strength and crash behavior in-house.”

When comparing the 1999 R8R and the

R18 e-tron quattro, 14 years of progress in all areas

become evident – starting on the outside. The first car



9

On its debut, Audi opted for a conventionally designed sports car. A V8

bi-turbo unit powered the mid-engine race car. Its water radiators were

installed at the front. At both the Sebring 12 Hours and the Le Mans

24 Hours, Audi celebrated a podium finish with the roadster. Its opponents

at La Sarthe back then were the factory teams of Mercedes-Benz, Nissan,

Toyota, BMW and Panoz.

Audi’s so far most successful sports prototype owes its list of 63 victories in

80 races to its concept, as well as to its long life. Five of the sports car’s six

runs at Le Mans ended in victory, despite increasingly severe limitations

imposed on power and performance by the regulations. In addition to

constant further development of aerodynamics, the engine changed as

well. In 2001, TFSI gasoline direct injection made its debut.

Unbeaten – this is the strong track record of the Audi R10 TDI at Le Mans.

Visually, the revolutionary car still bore some resemblance to its

predecessor, the R8. But the V12 TDI engine with more than 650 hp was a

pioneering achievement. From the cooling system to the wheelbase, from

the axle load distribution to the aerodynamic concept, every area was

affected by the diesel revolution.

Audi’s last open sports car to date secured its entry in the history books. In

2010, Audi set a new distance record with the innovative roadster at the

Le Mans 24 Hours. Its V10 TDI engine paved the way for VTG turbocharger

technology in racing, its lithium-ion battery and LED high-beam headlights

rang in a new era in other areas as well.

Audi ultra-lightweight technology was embodied by the R18 TDI in an

exemplary way. The engineers created a lot of reserves for ideal positioning

of ballast weight. Thus, the sports car powered by a V6 TDI engine excelled

in delivering well-balanced handling. The closed sports car won one of the

most thrilling Le Mans races in recent history with a 13.854-second

advantage.

Visually a close relative of the R18 TDI, the R18 e-tron quattro carried the

next revolution under its body work. The V6 TDI engine continued to drive

the rear wheels. A hybrid system at the front axle completed the

powertrain. A flywheel accumulator stored the recuperated energy and

supplied it to the front wheels again on acceleration. The prototype

immediately won the race.

In 2013, Audi is relying on an evolution of the revolution. The hybrid sports

car has a more efficient hybrid system, new details and modern assistance

systems such as the digital inside mirror and LED headlights with matrix-

beam technology. Specifically for Le Mans, Audi has developed a new overall

aerodynamics concept. The long-tail body catches the eye. Now, the

bodywork is flush with the rear wing.

Audi R8R (1999)

The development of the seven

generations of LMP race cars

Audi R8 (2000–2005)

Audi R10 TDI (2006–2008)

Audi R15 TDI (2009–2010)

Audi R18 TDI (2011)

Audi R18 e-tron quattro (2012)

Audi R18 e-tron quattro (2013)



10

Audi has acquired a

wealth of know-

how in order to

master alltechnologies in-

house – from

working with

materials through

to engineering

design, calculation

and simulation.

The period between Audi’s first run at Le Mans in1999 and today has seen major development leaps



11

featuring a roadster concept, which laid the foundation

for the ‘R’ being used in the name of the ‘R8’ model rangeabbreviation, looks pretty plain by today’s standards.

But how can progress be measured?

Dr. Mühlmeier cites weight as an impres-

sive example: “With the R8R we met the prescribed

minimum weight of 900 kilograms with relatively high

accuracy. Today, an R18 e-tron quattro that tips the

scales at 915 kilos weighs almost the same. However, it

is powered by a diesel engine, which is heavier due to its

basic design, has a closed cockpit and contains a complex

hybrid system. Still, it remains below the minimum

weight. That’s why we can work with ballast weight on

the set-up.”

How are such major strides achieved?

“When we were developing our first car, a steel roll bar

was typically used,” recalls Mühlmeier, who has a PhD in

engineering. “As of 2000, an integrated CFRP roll bar

was implemented. Since 2011, we have been fielding theR18 with a closed monocoque that is completely made of

CFRP and features a one-piece design.” In the case of the

body, a lot has changed as well. The first skin was

designed for relatively high robustness and permitted

severe body contact in duels. Now, the body consists of a

Audi’s in-house responsibilities for its LMP sport s cars have long included aerodynamics as well

Audi uses Le Mans as a technology lab



12

very thin-layered carbon construction. The steering sys-

tem is another example. In 1999, power steering was

still a hydraulic system supported by the engine. Since

the R10 TDI, which made its debut in 2006, the driver’s

work at the wheel has been electrically assisted.

ultra-lightweight design, which achieves

significant savings in current Audi production models, is

desirable in all areas of racing. The suspension of the

LMP sports prototypes has become notably lighter. The

lithium-ion battery that has been used since the 2009

R15 TDI saved 7 kilograms of weight compared with a

lead battery. One of the major single steps the engineers

achieved concerned the carbon f iber transmission: Since

2012, Audi has been saving a double-digit number of

kilos in just one step.

At the same time, the engineers

improved the efficiency of the entire race car. Aerody-

namically, the R18 e-tron quattro is a lot more efficient

than the first model. Engine technology has even seen

true leaps in efficiency. Not only the switch from gaso-

line to diesel engines in 2006 represented a major step,

as the current V6 TDI engine makes very favorable fuelconsumption possible. More than 20 percent fuel sav-

ings have been achieved in the diesel era. Next season, a

fundamentally different set of regulations will place an

even greater focus on efficiency.

ultra-lightweight design,

which achieves significant

savings in current Audiproduction models, is

desirable in all areas of

racing. The suspension of

the LMP sports

prototypes has become

notably lighter.

But Audi has not only clearly progressed

in terms of technology but also with respect to man-power. Today, a total of 250 employees are working for

Audi Sport at the Ingolstadt and Neckarsulm locations.

Under the direction of Audi Head of Motorsport Dr. Wolf-

gang Ullrich, they take care of the factory-backed motor-

sport commitments in the DTM and in the FIA World

Endurance Championship (WEC). For 2013, new respon-

sibilities have been established. Dieter Gass, as Head of

DTM, is responsible for the program with the Audi RS 5

DTM. Chris Reinke, as Head of LMP, manages the sports

car program with the Audi R18 e-tron quattro. Both

report directly to Dr. Ullrich, who has overall responsibil-

ity for all factory-backed programs. ◆

Chris Reinke wasTechnical Project

Manager in the pastand assumed overall

responsibility as Headof LMP in 2013



13

Audi is aiming for the brand’s twelfth Le Mans victory with the R 18 e-tron quattro



14

Advantage

through efficiency



15

Win rate

Audi has shaped the world’s most importantendurance race since 1999 like no other automobile manufacturer.Eleven victories in 14 events, including the 2010 distance record – andthe technology milestones set by the brand have been unrivaled too.



16

Two technological milestones in Audi’s Le Mans history were the introduction of TFSI gasoline direct injection in 2001 (above) and VTG turbocharger technologyin the R15 TDI eight years later



17

The relevance to

Audi’s seriesproducts is crucial

for innovations.

Audi celebrated one-two-three winsat Le Mans five times – the first timewas in 2000

The 24-hour race at Le Mans

has accelerated numerous

innovations since its inau-

gural event in 1923 – from

disc brakes (1953) to turbocharging (1974), from the

Wankel engine (1970) to carbon brakes (1990), from

TFSI gasoline direct injection (2001) to the first diesel

victory with the TDI (2006), from the VTG turbocharger

in Audi’s TDI engine (2009) through to the R18 e-tron

quattro (2012). It was the forst hybrid sports car that

won the race. Ever since Audi has been involved in the

most important endurance race, a single factor has

acquired crucial importance: efficiency – a core compe-

tency of the brand with the four rings.

In the course of a decade and a half,

Audi has launched numerous innovations at Le Mans. The

crucial aspect for the company, which carries the claim of

‘Vorsprung durch Technik’ in its name, is the relevance of

its inventions to the brand’s series products. Innovations

from racing have always been fed back into automotive

engineering. Conversely, motorsport has been benefiting

from the diverse know-how of AUDI AG’s Technical Devel-

opment (TE) time and time again.

Audi’s Le Mans track record to date

underscores the company’s forward-thinking work and

breaking records in the process. In 90 years of Le Mans

history since 1923, no other manufacturer has been able

to look back on such an amazing tradition of success sto-ries and technological milestones.

Audi has clinched eleven victories in

14 events since 1999. This equates to a rate of 78.6 per-

cent. With that, Audi has advanced to second place on

the all-time winners’ list with respect to the absolute

number of wins achieved. The current number one – Por-

sche – has taken 16 victories – albeit, from 1970 onward,

spread over a period of 28 years. Since 1923, 24 marques

have decided the endurance race in France in their favor.



18

Including its victories, Audi has cap-

tured 27 podium places at La Sarthe to date. This, too,equates to the runner-up’s spot on the all-time list of the

best contenders. A special reason to celebrate existed an

amazing five times, as in 2000, 2002, 2004, 2010 and

2012, Audi drivers took a clean sweep of the podium at

the classic endurance race.

With respect to an absolute best mark,

Audi has taken the lead. A distance record set by Porsche

existed since 1971. It was subsequently regarded as

being practically impossible to equal due to track conver-

sions. Two chicanes on the long Hunaudières straight

have been clearly slowing the race cars on the fastest

track sector to this day. Still, in 2010, Audi broke the

existing record when the victorious R15 TDI, having cov-

ered a distance of 5,410.713 kilometers, surpassed the

All eleven Le Mansvictories have beenclinched under thedirection of Headof Audi MotorsportDr. Wolfgang Ullrich

previous best mark by 75.4 kilometers. In the following

years, the regulations again significantly reduced theengine power of the LMP race cars. In addition, smaller

fuel tank capacities result in shorter pit stop intervals.

The progress achieved by Audi is the

result of targeted development. All innovations are

marked by two common factors: They are efficient and

relevant to production cars – this applies to TFSI gasoline

direct injection as well as to the TDI engine including the

VTG ( Variable Turbine Geometry) turbocharger, to quat-

tro four-wheel drive, to e-tron hybrid technology, to

ultra-lightweight design, to LED lighting technology and

to numerous other detailed solutions.

Various driver assistance systems that

make driving in normal road traffic easier and safer are



19

Four shafts and a motor-generator unit (MGU):The e-tron quattro hybrid system won at

Le Mans in 2012

gaining importance at Le Mans as well. A key prerequisite

for such innovations is the desirability of the related pro-

gress. Compared with the sporting rules for many inter-national touring car, formula or rally categories, the

regulations for LMP sports prototypes are particularly

conducive to fielding innovations and different concepts.

The competition at Le Mans regularly

shows that ‘Vorsprung durch Technik’ is measurable.

Right in the first decade of its program, Audi achieved

impressive improvements. From 2000 to 2010, fuel con-

sumption dropped by more than ten percent although

the average speed in the race increased from 208.6 to

225.2 km/h.

The milestone of the first hybrid victory

in 2012 was linked to another significant efficiency

increase: Consumption dropped to 33.34 liters – Audi

thus reduced it by ten percent within twelve months.

On June 22 and 23, on its 15th run at

Le Mans, the brand will be battling with three Audi R18

e-tron quattro cars to take its twelfth victory. In doing

so, the focus is placed on rigorous ultra-lightweight

design, optimized aerodynamics, an improved hybrid

system, engine modifications, driver assistance systems,

the matrix-beam headlight system and, of course, relia-

bility and efficiency.

“No other automobile manufacturer

has a track record of Le Mans technology and sporting

success that has been compressed into as short a time

span as Audi,” emphasizes Head of Audi Motorsport

Dr. Wolfgang Ullrich. “Le Mans has been pointing the way

Audi celebrated itsmost recent success

at Le Mans in 2012with the R18 e-tron

quattro sports car

to the future for a long time. The regulations promote

innovations and the most efficient solutions like no

other racing series does. We wish for this to continue tobe the case in the future. This presupposes maximum

equality of opportunity for different ideas.” ◆



20

Cell-culture



21

ultra-lightweight designAudi has cultivated ultra-lightweight design and sets

standards in the field of the sports prototypes. A comparison of the safetycells of the LMP race cars shows the magnitude of the improvementsachieved by the Audi engineers in the past 15 years of development.



22

Even the first cells – in this case the one used in the 2001 Audi R8 – consisted of CFRP.At that time, though, the race cars still had open cockpits

Since 1999, ultra-light-

weight design has been

playing a central role with

Audi’s Le Mans prototypes

(LMP). Materials such as CFRP (carbon fiber reinforced

plastic) harbor major potential for optimizing weight.

Although the first Audi LMP race car already had a mono-

coque made of the black fiber, the performance of thematerial that is still in use today has since been greatly

enhanced.

“In the space of 15 years, we’ve also

achieved major progress in the area of ultra-lightweight

design,” stresses Head of Audi Motorsport Dr. Wolfgang

Ullrich. “Audi’s LMP sports cars have continually become

lighter, stiffer, safer in crashes and more efficient. There

is hardly another motorsport discipline in which the crea-

tivity of the engineers is rewarded as highly as it is with

the Le Mans prototypes. Whether in terms of engineer-

ing design details or materials: many of the ultra-light-

weight ideas from motorsport have the potential of pos-

itively influencing the development of Audi’s production

models. Reducing the weight of the cars is the key to our

successful future – in motorsport and in production.”

Right in its first LMP sports car – the1999 R8R – Audi used a carbon fiber monocoque. Audi

has significantly been reducing weight to this day.

The monocoque is the central chassis

component. It supports the front axle, the front and lat-

eral body parts and, since 2012, the hybrid system. The

engine is directly connected to the rear. The monocoque

thus transmits the torsional and bending forces which

are introduced through the wheel suspensions, and

absorbs the impact energies that are generated in



23

The closed cell of theAudi R18 weighs onlyabout half as much asthe cell of the 1999R8R

With the R10 TDI, Audi integratedvarious functions and alreadyused parts of the cell as body skin

accidents – in frontal or side crashes as well as in roll-

overs. The chassis has become clearly more complex

since 2006. At that time, Audi introduced a third spring-

damper element on each axle. It allows the loads gener-

ated by aerodynamic downforce to be cushioned without

having a negative effect on the characteristics of any

individual wheel suspension element.

The Audi R8R (1999), the R8 (2000–

2005), the R10 TDI (2006–2008) and the R15 TDI (2009–

2010) all had open monocoques. With the R18 TDI

(2011), Audi used a closed cell for the first time. Its one-piece design is a trend-setter for safety and weight. Up

to then, the closed monocoques of competitors, for

manufacturing reasons, had been made up of several

elements.

Although a closed cockpit requires the

use of more material Audi has managed to cut the weight

of the monocoque in half between 1999 and today, while

surpassing all the safety and crash requirements of the

FIA. Furthermore, Audi managed to again increase the

torsional strength of the monocoque during this period

of time despite the 50-percent reduction in weight. The

comparison with a production car reveals interesting

facts: with similar torsional values, the weight of the

The one-piece design of the monocoques

used in the Audi R18 is a trendsetter in

terms of safety and weight.



24

Audi relies on VTG technology for theturbocharger – the unit shown here is for the R18.3.7 kilograms of weight could be saved early on

The CFRPtransmission

housing has beendesigned as a fully

stressed componentof the chassis

the transmission housing. Since 2012, it has been made

of a lightweight and stable full-carbon construction in

which the mounting points for the rear axle are inte-

grated. In addition, very light backstays from the mono-

coque to the transmission housing optimize the stiffness

of the rear end.

A chronological comparison illustrates

the significance of the progress that has been made in

ultra-lightweight design. The weight of a diesel engine,

due to its design, exceeds that of a comparable gasoline

engine in the two-digit percentage range. At the same

time, the Audi R18 e-tron quattro, since 2012, has been

accommodating a hybrid system including a motor at thefront axle. Still, the basic weight of the race car is below

the minimum of 915 kilograms. The ballast weight is

used to improve the set-up. The 1999 R8R, with a gaso-

line engine and without a hybrid system, weighed almost

exactly 900 kilograms and hardly offered any latitude

for ballast.

Numerous smaller solutions have been

accompanying the major steps. The carbon fiber gas

pedal in the Audi R10 TDI already saved a few hundred

grams of weight compared with an aluminum version,

and the lithium-ion battery that was used for the first

time in the 2009 R15 TDI even proved to be seven kilo-

grams lighter than a lead storage battery. The turbo-

charger offered room for improvement as well. By using

optimized components and a different material the engi-

neers saved nearly 3.7 kilograms of weight with the vari-

able-turbine-geometry turbocharger. At the same time,

the engineers reduced the inertia moment of the turbine

and the compressor wheels. Since then the response of

the turbocharger to gas pedal movements has been

clearly improved. ◆

carbon cell of the R18 only amounts to about a fourth of

the weight of a body-in-white made of steel sheet.

The torsional and bending stiffness of

the monocoque can only be completely effective if the

fully stressed assemblies of the engine and transmission

provide the corresponding stiffness. The V6 TDI engine

with a 120-degree cylinder bank angle is based on an

innovative architecture of the crankcase: Underneath the

main bearing, the crankcase is of a ladder frame design.

The lateral suction port of the dry sump and the finning

connect the bearing blocks with each other. In combina-

tion with the upper crankcase deck, this creates a stiff

unit. The engine and the monocoque have nearly the

same stiffness. This chassis design is complemented by



25

Audi used openmonocoques from1999 to 2010(above). A centralsupport alreadyoptimized the cell inthe R8 (center). TheR8’s successor, theR10 TDI, competedwith a V12 dieselengine (below)

An Audi R18 e-tron

quattro today, with a

diesel engine, hybrid

system and ballast

weight, weighs about

as much as a 1999

R8R without these

factors.



26

Surelyfaster

withsafety



27

Assistance systemsActive safety and passive safety are two basic

categories in automotive development. While active safety is designed toavoid accidents, passive safety serves to protect occupants in the event of an accident. Systems such as matrix-beam light that improve active safetyare becoming increasingly important in motorsport. Audi has achieved apioneering feat yet again.



28

Audi customers are inti-

mately familiar withassistance technology.

‘Audi side assist’ makes it

easier for the driver to change lanes by capturing the

traffi c situation using Radar, the ‘Audi pre sense’ safety

system helps avoid accidents, the night vision assistant

marks detected pedestrians – to name just a few exam-

ples. Not everything that is available in the entire range

of technology is suitable for racing though. Various

inventions are simply not allowed for use with Le Mans

prototypes. Race drivers are expected to demonstrate

their skills on the wheel and to battle for positions –

instead of leisurely following the car in front with ‘Audi

adaptive cruise control’ as a driver could in normal road

traffi c.

Still, new synergies are created

between production and racing. Currently, a digital sys-

tem to optimize vision is being used in the Le Mans pro-

totype. It may serve as a prototype for future produc-

tion automobiles. This digital rear-view mirror makes

rearward vision possible. A small camera is mounted on

the roof of the Audi R18 e-tron quattro above the driver.

The glass cover of the camera has a heater to prevent

fogging and icing. The lens has a size of only a few mil-

limeters and captures the traffi c behind the car with afield angle of 60 degrees. The electrical signal is trans-

mitted to a display in the cockpit. It is located in the

same position as a rear-view mirror in a production car.

As the rear of the monocoque facing the engine com-

partment has no window on a closed LMP model, a con-

ventional mirror cannot be used.

The display features innovative AMOLED

technology. The acronym stands for Active Matrix

Organic Light Emitting Diode, in other words an organic

light emitting diode with active matrix technology. Con-

trast is ten times better and energy consumption 30 per-

cent lower compared to a liquid crystal display. With a

screen diagonal of 6.8 inches, the display has a resolu-

tion of 600,000 pixels. Each pixel can be discretely

The daytime running lightof the Audi R10 TDI (above)consisted of LEDs. In the R15TDI, Audi initially used LEDs togenerate the daytime runninglight and subsequently thehigh-beam light (both picturedbelow). Ever since the R18 TDI(bottom), full LED headlightshave become standardequipment



29

controlled. The display has a thickness of merely seven

millimeters, including the mechanical components.

“This invention is of enormous help to

us,” stresses the two-time Le Mans winner and FIA WEC

World Champion Marcel Fässler. “The AMOLED display

has many advantages over a conventional mirror. It oper-

ates without any vibrations in any situation and provides

us drivers with particularly clear vision. The width of the

field angle is very helpful too. The blind spot, which is

typical for all closed LMP race cars, has simply

disappeared with our cars.”

Aside from these basic advantages, the

invention pays off particularly in the present-day era.

“Le Mans has long become a sprint race,” says the Swiss.

“That’s why we’re battling for every second even when

lapping in traffi c. The system helps us assess where the

rival’s car is, and this gives us higher safety reserves.

We’re in a much better position to judge when we can

change lines. And in a direct duel, we can tell whether a

rival attacks from the right or left.”

Although it does not belong to the

group of driver assistance systems, advanced lighting

The sight distance of the headlights has

increased by 85 percent since 2006.

800

R15

R10

836 m

482 m

453 m

4000 m

R18



30

There is a world of difference betweenthe steering wheels from 1999 and

today (right). Marcel Fässler is thrilledwith the current functions



31

technology clearly facilitates the work of the Audi fac-

tory drivers and increases active safety. Modern LED

light was used for the first time in the Audi R10 TDI from

2006 to 2008 – as daytime running lights. In the R15

TDI, the LED technology additionally functioned as the

high-beam headlight. Initially, the xenon headlights con-

tinued to be used alongside the LED lamps. Only the Audi

R18 that has been fielded since 2011 has been fully rely-

ing on LED light.

The high beam in the R15 TDI was

directly adopted from the production Audi R8. This pro-

duction sports car was the world’s first automobile to

use full LED headlights. Today, this technology is availa-

ble at Audi in the five model ranges R8, A8, A6, A7 Sport-back and A3. The lower energy consumption – around

80 watts instead of 135 watts with halogen units –

earned Audi an accolade in April 2013. The EU Commis-

sion measured the fuel savings in rig tests. The results

after ten NEDC cycles with the Audi A6 revealed that

more than one gram of carbon dioxide per kilometer

driven can be saved. With that, the EU Commission has

officially rated the LED headlights as an innovative tech-

nology to reduce CO2 emissions. Audi is the first manu-

facturer to have been awarded this certificate.

Audi has since started to rely on matrix-

beam technology. Its operating principle consists of sub-

dividing the LED high-beam light into a large number of

individual segments. The small single diodes, which work

in tandem with lenses or reflectors in front of them,

always deliver precise lighting without requiring a swivel

mechanism. They are discretely switched on and off or

dimmed, depending on the situation.

In a production automobile, the Audi

matrix LED headlights are supplied with the information

they need by a camera, the navigation system and other

sensors. When the camera captures other vehicles, the

new headlights specifically inactivate the high beam,which is made up of several sectors, in the relevant

sub-sector.

In racing, Audi uses this technology as a

cornering light. Principally, a headlight of the R18 e-tron

quattro consists of eight LED units. In addition, there is a

circumferential light band which, among other things,

serves as the turn signal. When entering the pit lane, it

switches to a color that has been allocated to the respec-

tive car number. This makes it possible for the mechanics

to identify their car from a distance. During the day, five

of the eight main diodes emit a low-beam light. At night,

in the high-beam mode, all eight LEDs are activated.

They generate a headlight sight distance of up to 836

meters. The enormous lighting intensity of the R18

headlights is more than two and a half times as high as

that of the predecessor, the R15. The color temperature

of 5,500 kelvins is similar to that of daylight. Conse-

quently, the driver’s eyes hardly get tired.

The cornering light assists the race

driver as soon as he turns into a corner. The LEDs on the

outside of the corner are dimmed whereas those on the

inside emit a brighter light. The transition is smooth andthe driver notices that illumination of the track in his line

of sight has improved. The system is controlled by soft-

ware which Audi has specifically developed for use in rac-

ing. Steering angle and speed are the influencing param-

eters captured by the system, which requires no

mechanism and is highly reliable. It thus perfectly com-

plements the basically high efficiency of modern lighting

technology. Audi has resolved the issue of the cooling

required for LEDs by targeted guidance of the airflow of

the moving vehicle. A separate fan is not necessary. That

is why the R18 headlights are one kilogram lighter than

the lighting units of the predecessor, the R15.

A third component has long evolved into

a valuable assistance system although it primarily serves

Audi successively integratedfurther functions into the

steering wheel – as in the 2001Audi R8 pictured here



32

a completely different purpose: the steering wheel. The

times when it merely served to change the car’s direction

of travel have been over for quite a while. A look at the

early days of the first Audi LMP sports car is astonishing.The 1999 R8R had a very simple three-spoke steering

wheel. Each spoke had an integrated button for activat-

ing the radio, high-beam headlight and the pit lane speed

limiter – that was all.

Today, the steering wheel is packed with

technology. Four paddles are installed on the back. The

driver uses them to shift gears, activate the pit lane

speed limiter and the passing light flasher. The steering

has an arrangement of 13 buttons. They are used to con-

trol frequently used basic functions, from brake balance

to traction control, from the radio to drink supply, from

the starter to the windshield wiper. In addition, there are

five rotary controls which the driver uses to influence the

engine and traction control maps, among other things.

An electronic display is centrally located

in the driver’s field of vision. It allows him to read the l ap

time as well as the times of individual track sectors, the

difference to previously set lap times or the inflationpressures of the four tires. Alarm functions are activated

when the fuel supply starts to go down or temperatures

begin to leave the permitted range. A rotary control

allows the driver to scroll between twelve menus.

The fact that an instrument which used

to be of elementary importance – the tachometer – no

longer exists as a classic gauge shows how much racing

has changed. Today, an array of shifting lamps at the

upper edge of the steering wheel indicates to the driver

when it is time to shift into a higher gear.

“There are many possibilities today that

didn’t exist in the past,” stresses Marcel Fässler. “The

steering wheel and the individual programs have been

The matrix-beam light of the AudiR18 e-tron quattro assists thedriver in cornering by dimming andintensifying the light



33

specifically developed by Audi. We now need to use these

functions a lot more because the communication

between the driver and the pits has become more inten-

sive. Today’s strategic considerations make a quickexchange of information particularly important. In the

LMP race car, we’ve got to react fast, for instance when

the tires degrade. We can directly influence the car’s

handling with individual controls. Looking at it this way,

the steering wheel is actually an assistance system.”

For the race driver on track, specific

functions are of particular use. “The worst thing is not to

have any radio contact,” relates the 2011 and 2012

Le Mans winner. “We urgently need information from the

pits. In the race, we most frequently change the ASR

function. The basic set-up of the traction control works

very well but we always readjust it a bit here and there.

Due to the weather, the tire inflation pressure, the condi-

tion of the tire tread or rubber pick-up on the track, grip

constantly changes.”

Summing it up, the Swiss is absolutely

convinced of the steering wheel as an assistance system:

“Across the distance of an endurance race, we need all

the possibilities that are available. With their complex-

ity, race cars such as the Audi R18 e-tron quattro repre-

sent the latest state of the art in technology and we’ve

got to master and use this technology as perfectly as

possible.” With leading-edge technology, Audi not onlymakes normal driving on the road easier for many cus-

tomers but for its race drivers on track as well. ◆

The AMOLED display,shown here in the R8e-tron, could becomerelevant for futureconsumer products as well

A tiny camera suppliesthe images for the

digital rear-view mirror

In view of today’s

strategy, the

steering wheelwith its

additional

functions has

become an

important

assistance

system.



34

Driving

force



35

Engine technologyAudi’s prototype racing activities include a decade

and a half of engine development. The progress that has been achieved isnot always detectable at first glance. The regulations have repeatedlylimited major strides being made with respect to sheer power output –but the engineers compensated for many losses and have consistentlybeen improving efficiency.



36

Two major eras have shaped

Le Mans from the perspec-

tive of engine designers.

Up to 2005, gasoline

engines powered Audi’s LMP race cars, and since 2006

diesel units have been used. Although these are two

highly different concepts, they keep bringing up the

same question: How can the powertrain be optimized?

Audi has added valuable chapters to engine develop-

ment at Le Mans with a wealth of ideas and, by 2012,

has clinched eleven victories at the world’s toughest

endurance race.

For the engine constructors, the Le Mans

project began with a 3.6-liter gasoline engine. Two turbo-

chargers assisted the V8 unit in achieving a power output

of more than 400 kW (544 hp). Just a year later, output

had increased to more than 449 kW (610 hp).

“Our first great progress was gasoline

direct injection in 2001,” recalls Ulrich Baretzky, Head of

Engine Development at Audi Sport. “This made it possible

for us to significantly reduce fuel consumption.” It was

not the only achievement by his team. Improved drivabil-

ity and more favorable response behavior made the race

drivers’ work a lot easier – particularly in the Le Mans year

of 2001 that was hit by rain. Equally remarkable was the

fact that at the pit stops the starting time decreased by

up to 1.3 seconds because the directly injected fuel was

immediately burned.

1999 2000 2001 2002 2003 2004 2005

Race car R8R R8 R8 R8 R8 R8 R8

Engine type V8 V8 V8 V8 V8 V8 V8

Combustion principle Gasoline Gasoline Gasoline Gasoline Gasoline Gasoline Gasoline

Mixture formation MPI MPI TFSI TFSI TFSI TFSI TFSI

Number of turbochargers 2 2 2 2 2 2 2

Cubic capacity (cc) 3,600 3,600 3,600 3,600 3,600 3,600 3,600

Power output (kW/hp) > 400/544 449/610 449/610 449/610 404/550 404/550 382/520

Torque (Nm) > 600 700 750 > 700 > 700 > 700 > 700

Air restrictor (mm) 2 x 33.2 2 x 32.4 2 x32.4 2 x 32.4 2 x 30.7 2 x 30.7 2 x 29.9

Boost pressure (millibar) 1,670 1,670 1,670 1,670 1,670 1,670 1,670

Output per liter (kW/hp per l) > 111/151 125/169 125/169 125/169 112/153 112/153 106/144

Piston area output

(kW/hp per cylinder)

70/95

60/82

50/68

40/54

Change in regulations

(vs. prior year)Restrictor Restrictor Restrictor

Audi innovation

Fully

stressed

engine

TFSI

> 50/6856/76 56/76 56/76

51/69 51/6948/65

Gasoline engines



37

At Le Mans, Audi tested a specific com-

bustion process back then – the fuel was injected using an

air-formed instead of a wall-formed or jet-formed princi-

ple. This homogenous mixture formation subsequently

appeared in the first Audi available with standard FSI

technology. The principle that had been tested at Le Mans

replaced the planned stratified charge process. On the

road, FSI engines make fuel economy benefits of up to

15 percent possible.

Only five years later, Audi celebrated a

pioneering achievement with the TDI engine. After the

inventor of the TDI in 1989 had offered its first produc-

tion model – an Audi 100 – featuring this technology, the

brand, in 2006, immediately clinched the first victory of

a diesel sports car at Le Mans. From 5.5 liters of displace-

ment, the V12 engine of the Audi R10 TDI developed

more than 478 kW (650 hp). Its torque of over 1,100 Nm

was impressive as well.

“This was the first Audi diesel engine

with an aluminum cylinder block,” stresses Baretzky. “In

conjunction with pre-development and production devel-

opment, basic tests and trials for the V12 TDI were con-

ducted.”

But this was not the only area in which

racing profited from the know-how advantage of AUDI

AG’s Technical Development. The first racing pistons

incorporated experiences that had been gained in

2006 2007 2008 2009 2010 2011 2012 2013

R10 TDI R10 TDI R10 TDI R15 TDI R15 TDI R18 TDIR18 e-tron

quattro

R18 e-tron

quattro

V12 V12 V12 V10 V10 V6 V6 V6

Diesel Diesel Diesel Diesel Diesel Diesel Diesel Diesel

TDI TDI TDI TDI TDI TDI TDI TDI

2 2 2 2 2 1 1 1

5,500 5,500 5,500 5,500 5,500 3,700 3,700 3,700

> 478/650 > 478/650 > 478/650 > 441/600 > 440/598 > 397/540 > 375/510 > 360/490

> 1.100 > 1.100 > 1.100 > 1.050 > 1.050 > 900 > 850 > 850

2 x 39.9 2 x 39.9 2 x 39.9 2 x 37.9 2 x 37.52 x 33.5/

1 x 47.5

2 x 32.4/

1 x 45.81 x 45.1

2,940 2,940 2,940 2,750 2,590 2,960 2,800 2,800

> 87/118 > 87/118 > 87/118 > 80/109 > 80/109 > 107/146 > 101/138 > 97/132

Restrictor,

boost pressure

Restrictor,

boost pressure

Cubic capacity,

restrictor,

boost pressure

Restrictor,

boost pressureRestrictor

TDI VTG

Double-flow

turbocharger

design

> 40/54 > 40/54 > 40/54

> 44/60 > 44/60

> 66/90> 63/85

> 60/82

Diesel engines



38

Pre-Development. In designing the piston cavities, the

engineers pursued similar approaches with the racing

and the production engine. The injection system with two

high-pressure pumps and piezo injectors has been refined

by Audi for specific output and maximum efficiency in

racing. “Over the course of the years, there has been a

continuous increase in the injection pressures of thehydraulic system and the ignition pressures in the cylin-

der,” Baretzky goes on to explain. “This way, it was possi-

ble to optimize combustion and power output which, in

turn, has been benefiting the development on the pro-

duction side of the house to this day.”

The V12 TDI was followed by a V10 TDI in

2009, which still had a displacement of 5.5 liters. “It was

100 millimeters shorter and ten percent lighter than its

predecessor,” reveals the Audi developer. A major step

was achieved by Audi with the turbochargers. The variable

turbine geometry (VTG), a long-standing standard in vol-

ume car production, was introduced into racing in the V10

TDI following several years of development. “The biggest

challenge was posed by the temperatures of more than

1,000 degrees centigrade, which do not occur in

production cars,” explains the engineer. VTG technology

significantly improves the car’s response behavior. In

2010, Audi not only celebrated the Le Mans victory with

the R15 TDI but, after 397 laps and 5,410 kilometers on

track, broke the outright distance record that had existed

for 39 years.

The biggest step in recent years wasmarked by the new engine regulations for 2011. It was

centered on four objectives: a significant reduction of

fuel consumption, heightening the relevance to produc-

tion cars by means of downsizing, increasing lap times by

lowering maximum output and equalizing the output of

gasoline and diesel engines.

A much smaller cubic capacity was a

major step toward achieving these objectives. In the case

of diesel engines, the regulations forced the engineers to

reduce the volume by 1.8 to 3.7 liters. Audi developed a

V6 TDI engine packed with innovations. The exhaust side

is located inside the cylinder banks, which feature a

120 degree angle configuration. ‘Hot side in,’ is the name

of this concept.

A double-flow mono-turbocharger is

supplied with the exhaust gas from both banks and its

compressor is of a double-flow design as well. The aspi-

rated air is directed into two intercoolers by volutes with

two exits and subsequently into the two exhaust mani-

folds. VTG technology only makes use of a mono-turbo-

charger possible in the first place. The turbocharger’s

response behavior would be unthinkable without such

technology in racing.

More and more new restrictions imposed

by the regulations are contrasted by continuous progress

being made by the Audi engineers. The diameter of the air

restrictor in the diesel era, for example, has been reduced

by 34 percent since 2006. The boost pressure has

decreased by 4.7 percent and the cubic capacity of the

engine by nearly 33 percent. Absolute power output has

dropped from over 478 kW (650 hp) to around 360 kW

(490 hp) today, in other words by around 24 percent.

Considering this, the increases achieved

with respect to specific output are particularly notewor-

thy. For instance, the engine output per liter of displace-

ment went up from 87 kW (118 hp) in 2006 to 107 kW

Audi has achieved significant improvements

with respect to specific outputs.

Consumption (l/100 km)

R10 R15 R18

100% -8% -21%



39

Ulrich Baretzky is in charge of engine development at Audi Sport The current turbocharger – the compressor side is shown here –is of a double-flow design

(146 hp) in 2011 – a gain of almost 24 percent. The piston

area output – in other words the measure for the output

delivered by each individual cylinder – grew from 40 kW

(54 hp) to 66 kW (90 hp), and thus by 65 percent, during

this time frame. Even more impressive is the fuel con-

sumption development. “We’ve improved fuel consump-

tion per lap in racing operations at Le Mans from the firstdiesel generation in the R10 TDI to the latest generation

by more than 20 percent, and this has been achieved with

a clearly higher output per liter,” emphasizes Baretzky.

The higher injection pressure of the Bosch racing injector

ensures even more efficient combustion, while the engine

has now been designed to withstand permanent combus-

tion pressures of clearly above 200 bar.

“All these improvements reflect the

great strides that have been achieved in combustion pro-

cess development and with the components used,”

explains Ulrich Baretzky. “They also reflect an under-standing of the mechanical loads that act on the engine

plus the optimization of friction. All of the progress that

has been made has utmost relevance for production car

development, which deals with the same topics. Le Mans

is an ideal lab for forward-thinking technologies.” ◆

Audi’s racing engines are created in Neckarsulm. The V6 TDI engine has already earned the brand two Le Mans victoriesand a World Champion’s title in the FIA WEC



40



AerodynamicsAt Le Mans, top performances in aerodynamics are

particularly valuable. Nowhere else are such high speeds driven with LMPsports cars. Thanks to improved airflow excellent lap times are consistentlyachieved over and over – despite the opposite effect of the regulations.

Air-Craft

41



42

The new long rear of the R18 e-tron quattro (left) has beendeveloped for Le Mans. Open cockpits such as the one of the

2006 R10 TDI in the wind tunnel (bottom) generated a lessfavorable airflow than the closed ones

Alook at Audi’s first proto-

type and its youngest one

is quite revealing, as the

differences between the

aerodynamic concepts of the two cars are clearly evi-

dent. The 1999 Audi R8R with an open cockpit is con-

trasted by the closed R18 e-tron quattro. And not a sin-

gle detail resembles another one.

When Audi built an LMP sports proto-

type for the first time 14 years ago, Fondmetal Technol-

ogies was the partner in aerodynamics. In Italy, the engi-

neers tested the air flow on the R8R using a 40-percent

scale model. Back then, such models had carbon fiber

tires that were fixed in position from the outside.

“Today’s state-of-the-art technology is completely dif-

ferent,” explains Axel Löffler, who as Head of Design

The aerodynamic

concepts from

1999 until todayclearly differ from

each other.



43

The CFD simulation shows the airflow around the supported (left) and the suspended rear wing (right). The thickness of the boundary layer is shown inred. When the boundary layer separates from the profile, this results in an undesirable break-away (left) and downforce decreases

The rear wing suspendedfrom the top has beencompensating for manylosses since 2009 thatresulted from changesin the regulations

Chassis/Bodywork was also responsible for aerodynam-

ics for many years before Jan Monchaux assumed respon-

sibility for this function in 2013. “We’ve now reached a

model size of 60 percent. Thanks to today’s rubber tires

we can create the airflow around the model with a lot

more realism. Likewise, a moving floor in the wind tunnel

helps us obtain more accurate measurement results. The

suspensions of the models have also been fully emulatedand are movable today.”

The basic aerodynamic concept of the

various evolutions of the LMP race cars from Ingolstadt

and Neckarsulm has obviously been subjected to further

development. In 1999, the radiators of the engine still

lay flat at the front end. The warm exit air escaped from

the hood in front of the cockpit opening, partially flow-

ing across the top of the cockpit and to the right and left.

To optimize airflow to the rear end, Audi has been inte-

grating the radiators and intercoolers into the side pods

in the Audi R8 as of 2000. “This has clearly improved air-

flow,” says Löffler. “Plus we gained some new freedom

of design at the front end. We were able to guide the ex it

air of the front diffusor with much higher precision.”

Audi took yet another step with the R15

TDI, which set a new distance record at Le Mans in 2010.

“The car’s extremely high nose made it possible for us toguide the air to the underfloor with even less eddying

than before. This supports the ground effect, in other

words the suction generated by the underfloor,” says

the expert.

But improvements are not always

achieved. The aerodynamicists repeatedly had to accept

limitations. When diesel direct injection was introduced

in the Audi R10 TDI in the 2006 season the cooling

requirements increased by around 30 percent due to the

different combustion process. Furthermore, the Audi



44

R18 e-tron quattro that has been fielded since 2012 hasa low-temperature circuit for cooling the hybrid system,

which poses an additional challenge. Still, no other Audi

LMP sports car has ever been as aerodynamically effi-

cient as the current hybrid sports car.

Existing latitudes are limited by the

regulations time and again. For example, when the pro-

ject was launched in 1999, the rear wing was allowed to

fill a maximum volume of 2,000 mm (width) x 400 mm

(length) x 150 mm (height). Today, these dimensions

have been reduced to 1,600 x 250 x 150 mm. Through a

large number of individual solutions, such as the rear

wing suspended from the top since the 2009 R15 TDI,

Audi has compensated for a major portion of the lost

downforce. It allows significantly improved airflow to

The regulations by nowhave severely limited

many of the latitudes in

aerodynamics.



45

the wing. For comparison: If the wing supports areinstalled at the bottom, downforce is significantly

reduced. The new mounting principle was subsequently

used by many other constructors too.

The specifications for the underfloor

were significantly modified as well. As of the Audi R10

TDI (2006), the specifications have been requiring a

seven-degree increase of the profile cross-section

toward the sides and a wooden board being installed

underneath the chassis. Despite such limitations a mod-

ern LMP sports car achieves very high levels of down-

force. Theoretically, at high speed, it could run on the

ceiling of a tunnel without falling down. The aerody-

namic loads involved are instructive. The front diffusor,

for instance, together with the rear wing generates half

of the downforce, while the underfloor including the rear

diffusor delivers the other half. This downforce is coun-

teracted by the inevitable lift that is caused by the air-flow through the cockpit and over the body. It accounts

for around a fourth of the downforce produced.

“The regulations have since been

severely limiting the freedom in aerodynamics,” says

Axel Löffler. “In the past, we were able to use the desired

aerodynamic configurations of the Audi R8 for fast tracks

like Le Mans as well as for slower road courses in the

American Le Mans Series with a single body version. Now,

the minimal latitude that is allowed forces us to optimize

a car for a single requirement. That’s why a long-tail ver-

sion of the R18 e-tron quattro was created just for

Le Mans 2013.”

The long rear end is only the most visi-

ble change. The entire aerodynamics of the hybrid sports

car has been modified for Le Mans in 2013 to meet the

special demands. An example of numbers illustrates how

Aerodynamic

efficiency

R8R R18

+65%



46

Significant development steps inaerodynamics are also detectable in detailbetween the beginning of the diesel era in

2006 with the R10 TDI (right) and the currentR18 e-tron quattro (below)

The rear wing width of 2,000 millimeters for a car like the Audi R10 TDI (below) hasbeen limited to only 1,600 millimeters today



47

extreme the conditions are: A year ago, Audi factory

driver Loïc Duval set the fastest lap in the 24-hour race at

La Sarthe, achieving an average speed of 240.289 km/h.

Including all the times the car spent at rest during 33 pit

stops, the victorious R18 e-tron quattro of Marcel

Fässler/André Lotterer/Benoît Tréluyer still achieved an

average of 214.468 km/h that was thus clearly above the

200 km/h-mark. There is no other circuit in the FIA

World Endurance Championship (WEC) where the cars

run as fast as this.

Engineers keep finding ways to improve

aerodynamic efficiency – in other words the relationship

between downforce and aerodynamic drag. This ratio

expresses the degree to which the aerodynamicists have

improved the downforce of a race car without an equiva-

lent increase in drag. Since 1999, Audi has improved the

aerodynamic efficiency of its LMP sports cars by around

65 percent.

“The lap times reflect the significance

of the strides that have been made in aerodynamics,”

emphasizes Head of Audi Motorsport Dr. Wolfgang Ull-rich. “Of course there are many other influencing fac-

tors – the powertrain, the tires, the chassis, the ultra-

lightweight design or the distribution of weight. To name

just one example for the sake of comparison: In 2006,

the fastest race lap at Le Mans was 3m 31.211s. The R10

TDI back then had 12 cylinders, 5.5 liters of displace-

ment and, delivering more than 650 hp, was our most

powerful LMP race car. Six years later, the best lap time

was 3m 24.189s. Our cars had become more than seven

seconds faster. But the V6 TDI engine of the Audi R18

ultra in 2012 was only allowed to have a displacement of

3.7 liters and delivered around 510 hp. A major share of

these advances is owed to optimized aerodynamics.” ◆

At Le Mans, the Audi R18 e-tron quattro is running as a long-tail version in 2013

Axel Löffler shapedthe aerodynamicsof the Audi sportsprototypes for manyyears



48

Looking at



49

Interview with Dr. Wolfgang UllrichHead of Audi Motorsport Dr. Ullrich takes a look at the

sports car future and assesses the greatest change in the regulations sinceAudi first built an LMP sports car in 1999.

2014



50

Adecade-long philosophy

in racing is now chang-ing. The regulations are

no longer focused on

interventions that limit power output. Instead, they

promote an energy-based approach to efficient race

cars. Does this mark a revolution in thinking?

Dr. Ullrich This solution for the regula-

tions very much represents a forward-thinking approach.

And clearly, Audi will increasingly position itself toward

efficiency and energy awareness in the future. Motor-

sport gives us a very good opportunity to properly pre-

pare ourselves for the future with an efficient concept at

the highest competitive level. With the new regulations,

a fundamental approach to motorsport is being aban-

doned. Instead of power output, energy consumption

will be limited. This entails two major consequences: For

the engineers, it opens up some degrees of technical

freedom, as previous limitations imposed on cubic capac-

ity or on the number of cylinders basically cease to exist.

Furthermore, energy consumption is drastically reduced.

Only a specified amount of energy will be available for a

certain distance. In the end, those doing the best job of

managing this amount of energy will be the fastest.

Efficiency is the aim while the competi-

tion between various technological concepts is beingaccelerated. What prerequisites have to be established

to ensure a fair competition?

Dr. Ullrich It’s anything but easy to for-

mulate a set of regulations for different concepts with

all their potential as well as their advantages and disad-

vantages. The aim is to put everyone in a position of

being in contention for victory with a well-developed

concept. This is exactly what the officials have to

strive for.

Audi has been relying on TDI power at

Le Mans since 2006. A diesel engine is a thermal engine

the efficiency of which has traditionally been higher

than that of a gasoline engine. Does this make ratings

more difficult?

Dr. Ullrich It makes ratings more diffi-

cult in that currently, in the 2013 season, we’re the only

entrants competing with a diesel engine. So we’re in a

demanding situation today. In the ideal case, equality of

opportunity exists bet ween the concepts. To ensure this

poses a challenge. It starts with the definition of the

fuel – this aspect alone leads to consequences in the

design of any engine. But it’s also about the available

energy classes relating to energy recovery. Factory

teams have to decide between 2, 4, 6 and 8 megajoules

with respect to the amount of energy. For the largest

amount of energy, you need a system which, according to

the current state of the art, is also the largest one and

thus weighs the most. A race car with a gasoline engine,

however, has more latitude when it comes to weight than

a diesel sports car which, for technical reasons, is heavier.

And this is just one, albeit obvious factor to be consid-ered in the selection of the concept.

The intensity of the competition is

being promoted. As a result, there is a threat of costs

going up. Do the current regulations include any cost

limitations?

Dr. Ullrich The release of the different

concepts strictly in relation to energy will certainly

require an intensification of the development invest-

ments for new vehicles in the initial step. All the manu-

facturers, the FIA and the ACO are looking at this issue.

We’re intensively working to avoid costs getting out of

hand without controls because that would be equally

inappropriate in this day and age as a non-efficient

powertrain in an inefficient race car.

The Audi R18 e-tron quattrois competing in its secondseason in 2013 before afundamentally new set of regulations applies in 2014



51

“Motorsport gives us a very good

opportunity to properly prepare

ourselves for the future with an

efficient concept at the highest level.”

There have been energy limitations in

motorsport before, in the nineteen-eighties. This led to

races that were run very tactically toward the end when

the energy was almost used up. Has this risk been

curbed today?

Dr. Ullrich The new regulations have not

been designed to make the entire amount of energy

available for optional use in the race. Instead, the fuel

flow per lap will be limited. And that’s exactly why we’ll

be seeing real, fiercely fought races and no economyruns. Consequently, it’ll be necessary to squeeze the

optimum out of a system, to develop an efficient vehicle

as well as an efficient internal combustion engine and to

make perfect use of the energy recuperation systems.

This makes different concepts and strategies possible.

All the parties involved have been paying attention to

ensuring that we’ll be seeing races and no economy runs.And despite this, the LMP sports cars will be consuming

less fuel than ever before. ◆



52

Two ways,

one aim



53

DTM–LMP comparisonThey could hardly be any more different – the Audi

RS 5 DTM and the R18 e-tron quattro. Still, there are some things whichboth race cars from Audi’s factory programs in the DTM and WEC have incommon. Plus, both are pursuing the same aim – success.



54

There was a time when a

touring car was an opti-

mized production model.

Audi often proved that it is

possible to be successful in motorsport with such cars.

In 1990 and 1991, the Audi V8 quattro won the DTM

twice in succession. No other automobile manufacturer

had achieved this feat before. The Group A race cars were

created on the basis of a production Audi V8. The follow-

ing years again showed that a good production touring

car provides a viable base for great success in racing. The

Audi 80 competition and the Audi A4 quattro, prepared

according to Super Touring Car regulations, won titles

for Audi worldwide.

Since the 2000 season, different rules

have applied in the DTM – a kind of touring car prototype

took the place of production concepts. Although the

Audi A4 DTM resembled the volume production model it

was based on a steel space frame and relied on mechani-cal systems strictly designed for racing in all areas such

as the suspension, aerodynamics, the engine and the

transmission. Audi won the DTM Championship with it

five times.

In 2012, new rules were introduced yet

again while the idea of a pure race car concept has been

retained. A carryover-parts-principle for the three manu-

facturers involved in the DTM prescribes a large number

of shared component assemblies. For example, the car-

bon fiber monocoque including the steel roll cage is iden-

tical for the Audi RS 5 DTM and its competitors.

Basically, these touring cars rely on a

material in a central, stressed component that has been

used as the standard material for Audi’s sports proto-

types since 1999: carbon fiber reinforced plastic (CFRP).

The material is comparable but the results differ. In the

DTM, the monocoque consists of carbon fiber up to the

belt line. Above it, a rugged steel cage protects the driver

and serves as the mounting point for the bodywork and

other parts. Six carbon fiber elements – one each at the

front and rear – additionally absorb the impact energy in

accidents. Since 2000, individual tubular steel frames

and a CFRP cockpit were standard in the DTM.

The cell of the Audi RS 5DTM is a carryover part forall three manufacturers in

the DTM

For the hybrid drive, theAudi R18 e-tron quattro

requires dedicated

developments

Touring and sports carsmutually benefit from

various calculationmethods



55

In the Audi R18 e-tron quattro sports

car, the entire one-piece monocoque is made of carbon.

While the cost-optimized DTM design weighs around

130 kilograms, the performance-optimized sports car

cell tips the scales at less than half of this weight. By tak-

ing the step in favor of an identical monocoque the DTM

has clearly progressed in terms of passive safety.

Even though the number of almost

60 carryover parts between the three manufacturers in

the DTM appears to be small, the effects should not be

underestimated. “The monocoque is a particularly largecomponent,” emphasizes Dr. Martin Mühlmeier, Head of

Technology at Audi Sport. “The transmission and the drive

shaft are identical. For the suspension, the mounting

points are severely limited and the material is specified.

For the engine, a minimum weight is prescribed.” By con-

trast, the Audi R18 e-tron quattro offers a lot of engi-

neering freedom. There are no carryover parts, different

types of internal combustion engines such as gasoline or

diesel units are allowed, the number of cylinders may vary

and the regulations provide a lot of latitude with respect

to numerous other parameters. Similarly, the limitations

imposed on the chassis are much smaller as well.

“By the same token, we’ve got a lot of

freedom with the Audi R18 e-tron quattro in terms of

aerodynamics too,” says Dr. Mühlmeier. “In the DTM, the

underfloor is geometrically specified, from the front to

the rear diffusor. The same applies to the rear wing.”

The direct comparison between both

cars is crystal-clear for the Head of Technology: “The

number of variables is significantly lower for a DTM race

car. The regulations have deliberately reduced the com-

plexity of the car. As a result, the manpower required to

construct the race car, in simulation and in further devel-

opment is clearly lower.”

At Audi Sport, both projects benefit

from each other nonetheless. “We use the same pro-

grams for aerodynamics calculations by means of com-

putational fluid dynamics (CFD) and in engineering

design with the finite elements method (FEM),” explains

the engineer. “The departments and the employees that

deal with many of the various questions arising in the

DTM and LMP are the same.” Special developments,

though, are necessary to develop and test the hybrid sys-

tem of the R18 e-tron quattro.

“Despite all the differences between

the race cars, at Audi, we’ve repeatedly been able to use

synergies benefiting both projects for years,” stresses

Dr. Martin Mühlmeier. ◆

At Audi Sport, theDTM and LMP

projects benefit

from each other.

As Head of Technology, Dr. MartinMühlmeier (left) is r esponsible for

the Audi RS 5 DTM and the R18 e-tronquattro. Andreas Roos (right) switchedfrom the DTM to the WEC as Technical

Team Coordinator



56

Number facts

Interestingdetails about the 24-hour race.

The things

that countat Le Mans

363.7

6,239

meters is the range of the light emitted by the LED headlights

kilograms of weight were saved by Audi right in the first

development year by optimizing the VTG turbocharger

kilometers were covered by the

victorious Audi R18 e-tron

quattro in practice, qualifying

and the race in 2012



57

3315,800

25

pit stops with a total stopping time of 40m 59.968s for

refueling, tire and driver changes were performed bythe winning team in 2012

5,100braking maneuvers are

performed by a race

car like the Audi R18

e-tron quattro in

24 hours

Around

shifting events have to be handled by the six-speed

transmission at the Le Mans 24 Hours without fail

b ar i s

t h e pr e s s ur e l ev e l i n t h eh y d r a u l i c r ai l s

y s t em of t h eV 6 T D I en gi n e’ s i n j e c t i on s y s t em

percent of GTL (Gas-to-Liquid) and BTL

(Biomass to Liquid) is the biofuel content

of the identical diesel fuel used at

Le Mans. BTL is a second-generation

biofuel, which is exclusively produced

from agricultural waste



58

Share andshare alike



59

Audi R8 LMS ultra and Audi R8

The Audi R8 is an excellent athlete. The thoroughlyrevised production sports car has won numerous international awards,most recently the red dot award for top design quality. It generouslyshares a range of components with its racing ‘brother,’ the R8 LMS ultra,which has been collecting numerous trophies in motorsport.



60

The photo is almost an invita-

tion to a hidden-objects-

game: Who can find the dif-

ferences? At first glance the

body-in-white of the Audi R8 on the lifting platform in

Heilbronn-Biberach looks as if it is about to turn into an

Audi for the consumer. In fact, it actually comes from the

production site of quattro GmbH at the Neckarsulm loca-

tion where more than 20,000 Audi R8 cars have left the

assembly line since 2006.

The connection of extruded profiles,gussets and panels plus the light-gray primer and wir-

ing – everything looks like the body-in-white for the pro-

duction automobile. Only a peek into the interior reveals

that the roll cage does not belong in a road-going vehi-

cle. This is precisely the point at which the common gene-

alogical tree of production and racing splits into two

branches.

The 210-kilogram Audi Space Frame

(ASF) is the ideal backbone for both versions. With its

torsional stiffness, ultra-light weight and very high

safety it is optimally suited for a race car. Before leaving

the assembly line, the racing version is fitted with a steel

roll cage as prescribed by the regulations. In addition,

space is created for the installation of air jacks that allow

the race car to lift on its own as soon as compressed air is

An underfloor is installed underneath the production-based ASF chassis of the GT3 sport s car for aerodynamic reasons

After 10,000 kilometers, the racing engine

requires a minor maintenance service,

rebuilding it follows only after 20,000.



61

pumped into the system at the rear by an air gun. At a pitstop, the R8 LMS ultra thus immediately starts hovering

in the air and the wheels can be changed.

More than 50 percent of all the parts of

the race car are adopted from production vehicles. Even

seasoned motorsport experts are amazed over and over

about the quality of the genes of the road-going sports

cars,” says Romolo Liebchen, who today is Head of the cus-

tomer sport department of Audi Sport customer racing.

Numerous facts prove how expertly this

has been achieved. The chassis, for example, not only

lasts for the entire lifetime of an automobile or, in rac-

ing, perfectly holds up to an endurance distance such as

the 24-hour races at the Nürburgring or at Spa – both

The body-in-white of the Audi R8 LMS ultra originates from the road car production line in Neckarsulm

Around half of the components underneath thecarbon skin are production parts



62

events having been won by the GT3 race car in 2012 – as

individual race cars sold by Audi to customers since 2009

have by now covered tens of thousands of kilometers,

notably at racing speed. A case in point: Chassis number

AS42AOFGT3110319 did its first laps at a functional test

on March 29, 2011, followed by a 4-hour race plus a

24-hour race at the Nürburgring. In July, the R8 LMS was

run in another 24-hour race at Spa plus a 12-hour race in

Malaysia in September. In November, Edoardo Mortara

won the GT Cup in Macau with it. In February 2012, the

Audi won the Bathurst 12 Hours in Australia. It was sub-

sequently sold to a local team that has since clinched fur-

ther success with it. Within a year and a half, the GT3

sports car has covered 12,667 race kilometers – not

counting the practice and qualifying sessions.

“Such distances represent testing at an

accelerated rate,” says Romolo Liebchen. “Audi hasgained quite a few findings from this which are fed back

into the production side of the house.” The relevant

questions are typically not of a fundamental nature but

often relate to minor areas in which learning effects

occur: joining techniques, design-related parameters,

possibilities of implementing motorsport ideas or clever

details that facilitate the work of the race teams.

The viability of production solutions in

two other areas is amazing. The transverse links (wish-

bones) that guide the four wheels can be recognized as

production parts for road-going models at first glance.

“They actually originate from the production side. We

modified them for racing,” reveals Liebchen. Cornering

forces of more than 2g, deceleration forces when brak-

ing with up to 31-centimeter wide slicks or the loads

occurring on the famous hilltop jump in sixth gear at the

‘Pflanzgarten’ on the Nürburgring: The suspension, sup-

ported by springs and dampers for racing, command-

ingly handles the brute force.

The benchmark is similarly high with the

engine. The 5.2-liter V10 FSI unit is produced at Audi’s

plant in Győr, Hungary, together with its production

counterparts. Only specific bearing locations are

On the Nordschleife of the Nürburgring, high loads act on the R8 LMS ultra

The rugged 5.2-liter V10 engine powers theproduction model and the GT3 sports car



63

subjected to minimal modifications. The engine’s stand-

ard dry-sump lubrication can even handle the extreme

centrifugal forces in racing. The exhaust system is a new

element. The tailpipe of the racing component is cen-

tered at the rear between the taillights.

“After 10,000 kilometers, we recom-

mend a minor maintenance service to our customers and

after 20,000 kilometers the engine is dismantled and

rebuilt for further races,” says Liebchen, describing the

service intervals for the 560-hp engine. “In the GT3 cat-

egory on an international scale, these are top marks.”

Customers directly benefit from this, as the rugged

power-plant is gentle on the budget.

Conversely, racing technology has longbeen fed into production models as well. The compart-

ment for the convertible top and the rear side panels of

the R8 Spyder are made of carbon fiber reinforced plastic

(CFRP). The material that combines strength and light

weight is also functionally used for the enlarged front

spoiler and the distinctive rear diffusor. CFRP has thus

long been playing a much greater role than only for vis-

ual carbon applications in the interior.

Within only five years, the racing pro-

ject with the Audi R8 LMS ultra has demonstrated that

the kinship between production and sport at Audi is far

more than a claim. The exchange is actively pursued,

benefits both areas and promotes the entire develop-

ment. This underlines the sportiness of the brand. ◆

The kinship

between

production and

sport at Audi is

far more than a

claim.Romolo Liebchen is Head of Audi Sport customer racing

The suspensionand the ASF frameoriginate from theproduction car andhave been modifiedfor racing

The cockpit of theR8 LMS ultra revealsa kinship to theproduction car aswell



64

From motorsportto production

Technology transfer

Audi is active inmotorsport in order to accelerate technicalprogress. Numerous interesting examplesprovide compelling proof points.

In 1980, the quattro marked the

beginning of the Audi brand’s suc-

cessful motorsport history and rise to the level of a tech-

nology trendsetter. Since then, Audi has built more than

five million vehicles with quattro drive. The more power-

ful models in particular are no longer thinkable without

permanent quattro all-wheel drive.

In 1985, Audi was the first automobile manufac-

turer to test a Torsen differential in rallying. Two

years later, the invention made its way into large-scale production, ini-

tially in the Audi 80/90 and later in all quattro models.

Audi is the inventor of the TDI engine. Since

2006 motorsport has been assisting Audi in its

continuing development of TDI technology: to control increasingly

high injection and ignition pressures, for example.

Lightweight design is a core topic in

motorsport and an Audi core com-

petence. Audi started to gather experience with alu-

minum in rallying and has been increasing its expertise in

CFRP with sports prototypes since 1999.

T

he “S tronic” transmission in which

two clutches allow the driver touse an engaged gear and pre-select a second one cele-

brated its debut in 1985, in the Audi Sport quattro S1.

Be it aluminum, magnesium or

composites – motorsport is often

a pioneer for production when it comes to using new

types of materials.

The combination of turbo charging and direct

injection is standard at Audi today. TFSI technol-

ogy celebrated its debut with a victory of the Audi R8 at the 2001

Le Mans 24 Hours.

quattro

Torsen differential andhollow shaft

S tronic

ultra-lightweight design

TDI Power

TFSI

Material technology



65

Maximum aerodynamic effi ciency

is a common aim of production

and motorsport development. The

production side takes up many ideas

from the sport. The enclosed under-

floor of the Audi A8 is just one

example.

Be it push-button engine starts or

various dynamics programs for

suspension, engine and transmission control: motor-

sport initially sparked their development.

I

n 2009, the Audi R15 TDI was the first Le Mans

sports car to be equipped with a lithium-ion bat-tery of the type used in hybrid electric vehicles and thus a forerunner

of the Audi R18 e-tron quattro.

The Audi R18 e-tron quattro has a digital rear-

view mirror with a camera and an AMOLED dis-

play. This technology is currently being tested at Audi for future use in

production applications.

S

ince 2001 Audi’s sports prototypes

have been equipped with a tirepressure monitoring system. Such systems can be

ordered for production models as well.

In the R18 e-tron quattro, Audi is

testing a new type of four-wheel

drive system in which one of the axles is electrically

driven. Audi is testing such technologies in production-

based test models as well.

Particularly by fielding TDI technology at Le Mans

Audi has been introducing new trends in reduc-

ing exhaust and noise emissions since 2006. The related know-how

has already been transferred to TDI production engines.

Audi is regarded as a pioneer in LED technology.

Currently, the R18 e-tron quattro, thanks to

Matrix-Beam, has a cornering light function in its full LED headlights.

Additional functions are possible in road traffi c. The new technology

will be making its debut in road cars within the foreseeable future.

Aerodynamics

Electrification

e-tron quattro

Matrix LED headlights

Assistance systems

Digital rear-view mirror

Safety

Emissions reduction



66

Jürgen Pippig

Head of Audi Communications Motorsport

Phone +49 841 8934200

[email protected]

Eva-Maria Veith

Communications LMP

Phone +49 841 8933922

[email protected]

Virginia Brusch

Communications Customer racing

Phone +49 841 8941753

[email protected]

AUDI AG

D-85045 Ingolstadt

Responsible for the content

Jürgen Pippig,

Head of Audi Communications Motorsport

I/GP-P4

Editor

Alexander von Wegner

Masthead

AUDI AG

Communications Motorsport

D-85045 Ingolstadt

Phone +49 841 8934200

Fax +49 841 8938617

E-mail [email protected]

Your contacts

Information sources

Daniel Schuster

Communications DTM

Phone +49 841 8938009

[email protected]

Petra Strack

Communications Motorsport

Phone +49 841 8954457

[email protected]

All texts and photographs contained in this MediaInfo magazine

are available for downloading from the internet (accreditation

required): www.audi-motorsport.info

Audi Sport App

(iOS/Android)

Audi Express

(iPad/Android)

Facebook

www.facebook.com/AudiSport

Twitter

@Audi__Sport



www.audi-motorsport.info

R18Digital rear-view mirror

TDIAMOLED

Matrix BeamLED

motorsport and production

Documents