Mercedes-Benz CLK DTM AMG Unveiled

Mercedes-Benz CLK DTM AMG Unveiled

Thoroughbred race-track technology for the road

May 3, 2004 6:40 AM
Filed Under: German, Mercedes-Benz

Press Release

Thoroughbred race-track technology for the road
With its combination of state-of-the-art motorsport technology, driving dynamics more familiar from the race-track, captivating styling features and unrivalled exclusivity, the new Mercedes-Benz CLK DTM AMG will set the pulses of car enthusiasts racing that much faster. Limited to a production run of only 100 units, this two-door masterpiece combines an AMG 5.5-litre V8 supercharged engine developing 428 kW/582 hp, a newly developed chassis, optionally available sports tyres and aerodynamics optimised in the wind tunnel to deliver a truly exceptional high-performance experience. The AMG thoroughbred accelerates from 0 to 100 km/h in just 3.9 seconds, and on to an electronically governed maximum speed of 320 km/h. The template for the development of the new CLK DTM AMG was the racing version of the Mercedes-Benz CLK, which Bernd Schneider drove to overall victory in the 2003 German Touring Car Masters (DTM) race series and which finished the season as the most successful model in the championship. The fixtures and fittings of the CLK DTM AMG also take their cue from its race-track sibling. Two leather-trimmed AMG sports bucket seats with four-point safety belts ensure unbeatable lateral support, whilst the oval AMG racing steering wheel with suede covering and new AMG instrument cluster with 360 km/h speedometer dial bring extra touches of motor racing allure to the interior. The first examples of the 100-unit limited-edition series will be delivered to customers from autumn 2004. You need look no further than the exterior design of the new CLK DTM AMG to find the first traces of its racing pedigree, the transfer of high-end motorsport technology to the road given visual expression by the low slung front apron with large cooling air inlets, striking fender flarings, 19 and 20-inch AMG light-alloy wheels and the diffusor-look rear section with rear wing, all of which recall the head-turning muscularity of the successful CLK racing touring cars competing in the DTM. Added to which, a host of body components have been constructed from the high-strength and extremely lightweight carbon-fibre-reinforced material CFRP. Under the bonnet lurks a specially revised version of the AMG supercharged eight-cylinder engine familiar from the SL 55 AMG, featuring modifications to the crankcase, pistons, valve train, cooling system, intake duct, supercharger and exhaust system. The AMG V8 engine develops 428 kW/582 hp at 6100 rpm from its 5439-cc displacement, with peak torque of 800 Newton metres available from 3500 rpm.
Performance comparable with a super sports car
Boasting instant accelerator response, impressive torque development, free-revving vivacity and an unmistakeable V8 soundtrack, the wonderfully powerful AMG 5.5-litre supercharged V8 at the heart of the CLK DTM AMG was born to deliver performance characteristics normally the preserve of super sports cars. The sprint from 0 to 100 km/h vanishes in only 3.9 seconds on the way to an electronically governed maximum speed of 320 km/h. The AMG SPEEDSHIFT five-speed automatic transmission injects further doses of mo-tor-racing magic into the new arrival. The driver changes gear with a short dab of the steer-ing-wheel-mounted shift paddles, the amazingly short shift times pushing back the boundaries of sporty driving and dynamic feel.
Newly developed spring and shock absorber units with adjustable coil springs, plus a locking differential on the rear axle
The chassis, meanwhile, is a more than worthy complement to the beguiling muscle of the powertrain. Already a firm fixture on the race-track, height-adjustable spring and shock ab-sorber units with adjustable coil springs are also an integral feature of the new road car. The rear axle has been redesigned to include totally new spring links and hub carriers, as well as reinforced drive shafts. Uniball joints on both axles replace rubber elements and imbue the car's driving characteristics with unrivalled precision. A multiple-disc limited-slip differential at the rear axle ensures optimum traction, whilst Acceleration Skid Control ASR and the Elec-tronic Stability Program ESP® have been adjusted to take into account the enhanced levels of performance.
Optional Dunlop sports tyres offer exceptional grip
Optionally available sports tyres from DTM motorsport partner Dunlop (225/35 R 19 at the front and 285/30 R 20 at the rear) help the car maintain unrivalled contact with the road surface. These tyres offer particularly high levels of grip and are fitted on multi-piece AMG light-alloy wheels in double-spoke design (front: 9 x 19, rear: 10 x 20) which have been developed ex-clusively for the CLK DTM AMG. Their visually alluring spokes are extremely effective not only when it comes to turning heads, but also in providing ventilation for the brakes. And the newly developed AMG high-performance composite braking system with six-piston fixed callipers at the front and four-piston fixed callipers at the rear can be relied on to ensure flawless decel-eration.
Functional racing-car ambience in the interior
Once inside the CLK DTM AMG, the driver is struck by a functional racing ambience laced with the trademark exclusivity of AMG high-performance cars. Two leather AMG sports bucket seats made from exceptionally lightweight CFRP and fitted with four-point safety belts offer the two occupants optimum lateral support, whilst the thick and oval-shaped rim of the high-grip suede-trimmed AMG racing steering wheel helps to transmit a particularly acute feel for the car. The door panels are made from CFRP, as are many other elements of the interior such as the instrument cluster. The newly designed centre console boasts a selection of eye-catching features, including the silver-coloured selector lever surround, the starter button, four rocker switches for auxiliary functions and a badge bearing the vehicle number. The racing credentials of the CLK DTM AMG have not in any way diluted its adherence to the hallmark virtues shared by all Mercedes models - practicality, durability, safety, quality and service all meet the highest standards. The racing-inspired AMG Coupé will be built by hand as part of a close cooperation between Mercedes-AMG GmbH and H.W.A. GmbH. One of the most successful touring car racing teams of all time, H.W.A. GmbH is also responsible for the development and running of the new C-Class DTM cars. The first examples of the 100-unit limited-edition CLK DTM AMG will be delivered to customers from autumn 2004. Mer-cedes-AMG GmbH is responsible for marketing, sales and service activities relating to the new car.

Technical details and equipment: Inheriting the genes of the DTM-winning car

The most successful car in the German Touring Car Masters (DTM) race series is set to transform its dominance on the track into a spectacular conquest of the roads. The CLK DTM AMG has inherited the genes of the DTM-winning Mercedes and possesses all the ingredients necessary to set the pulses of car and motorsport enthusiasts racing that extra bit faster. This exclusive AMG high-performance speedster is mod-elled both stylistically and technically on the car that romped away with the DTM title in 2003. Bernd Schneider drove the race-trim Mercedes-Benz CLK to the drivers’ championship, but was pushed all the way by team-mate Christijan Albers. AMG-Mercedes had previously topped the team standings in 2002 and 2003, also with the CLK. Last year, the impressive Coupé celebrated victory in nine out of the ten races on the calendar, ensuring that Mercedes-Benz also won the constructors’ champion-ship in some style. This history of success was a forceful source of inspiration for Mercedes-AMG GmbH in the development of the extraordinary new CLK DTM AMG. With its wide stance and low-slung posture, large cooling air inlets, striking fender flarings, a diffusor-look rear apron and an imposing rear wing, the high-performance AMG newcomer gives off a powerful aura even when it’s standing still. A significant number of body components are made from the ultra-lightweight carbon-fibre-reinforced material CFRP, whilst the rear wing generates downforce at high speeds, further improving directional stability and road adhesion. For example, when the car is travelling at 200 km/h downforce of 36 kilograms is exerted on the rear axle.
AMG 5.5-litre V8 supercharged engine with impressive credentials
The scene under the bonnet of the CLK DTM AMG is no less impressive. Eight cylin-ders, 5.5-litre displacement, a supercharger with low-temperature charge air cooling and numerous components which have honed their talents on the race-track make this a quite breathtaking creation in both style and substance. Developing output of 428 kW/582 hp and peak torque of 800 Newton metres at 3500 rpm, the AMG V8 supercharged power unit speaks the language of the super sports car elite. Its torque development is particularly outstanding, with 690 Newton metres of pulling power on tap as low down as 2000 revolutions per minute and the 750-Nm mark reached and breached just 500 rpm further around the dial. And the CLK DTM AMG has a bite to match its bark, powering from 0 to 100 km/h in a mere 3.9 seconds and 0 to 200 km/h in just 10.9 seconds. The sprint from 60 to 120 km/h is over in 3.8 seconds and maximum speed is electronically limited to 320 km/h.

The key engine and performance data at a glance:

    CLK DTM AMG
Cylinders/valves per cylinder V8/3
Displacement cc 5439
Bore x stroke mm 97.0 x 92.0
Compression ratio 10.5 : 1
Output kW/hp
at rpm 		428/582
6100
Torque Nm
at rpm 		800
3500
0 - 100 km/h s 3.9
0 - 200 km/h s 10.9
60 - 120 km/h s 3.8
Maximum speed km/h 320*
NEDC combined fuel
consumption l/100 km 		13.7

*electronically governed
Motorsport expertise at the heart of the engine development process
The V8 supercharged engine in the CLK DTM AMG is the product of the Mercedes-AMG engineers’ vast experience, gained from more than 35 years of involvement in motor racing and the construction and development of high-performance power units. The following components of the engine borrowed from the SL 55 AMG were newly designed and developed:
  • The crankcase from the SL 55 AMG power unit has been further strengthened.
  • The pistons are forged and made of a special material boasting extreme temperature and pressure-resistant properties.
  • The exhaust camshafts have extended valve opening times, which improves the fuel supply to the combustion chambers; in conjunction with the new fan-type exhaust pipes and the new sports exhaust system, exhaust gas backpressure is significantly reduced.
  • Optimised intake airflow leads to better air throughput in the cylinder heads.
  • The higher-revving screw-type supercharger raises charge pressure from 0.8 bar to 0.85 bar.
  • The engine electronics have been adapted to the unit’s upgraded performance characteristics.
Optimised charge air and engine oil cooling
The cooling system of the supercharged eight-cylinder power unit has also been optimised. The water-cooled intercooler with low-temperature circuit is fitted with additional radiators integrated into the front apron, which help to even out tempera-ture peaks. The extremely efficient engine oil cooler on the left of the system keeps the temperature of the lubricant at low levels even under heavy loads. The AMG engine is music to the ears of motorsport aficionados everywhere. Its new AMG sports exhaust system generates a vocal harmony reminiscent of the all-conquering CLK racers in the DTM. Cutting-edge exhaust technology, including two primary and two main catalytic converters, ensure that the CLK DTM AMG easily meets all emissions limits currently specified by law, as well as fulfilling the EU4 standard due to come into force in 2005. In addition to the 62-litre fuel tank fitted in the standard road-going CLK, the AMG Coupé is fitted with a 30-litre auxiliary tank above the rear axle. The battery and windscreen washing system have been relocated to the luggage compartment, helping – in tandem with other measures – to create a favourable weight distribution of 54 percent to 46 percent (front /rear axle). This is achieved despite the integration of the supercharger and the necessary cooling systems, which increase the weight on the front axle.
“One man, one engine� in the AMG engine workshop
The AMG 5.5-litre V8 supercharged engine in the CLK DTM AMG is hand-crafted with meticulous precision in the AMG engine workshop. The work is carried out by mechanics and at work stations selected specially for the job – as is the case with engine assembly in the racing department – on the same assembly line as the AMG V12 biturbo unit and the AMG engine for the SLR McLaren. The company’s philoso-phy of “one man, one engine� dictates that a single engineer is responsible for the complete assembly of each AMG high-performance power unit – a service documented by the engineer’s signature on a special engine plaque, which is positioned on the charger module in the case of the AMG V8 supercharged unit.
AMG SPEEDSHIFT with ergonomic steering wheel paddles enables particularly short shift times
The AMG SPEEDSHIFT five-speed automatic transmission takes control of power transmission in the new car and can be operated using paddles mounted on the AMG racing steering wheel. The extremely short shift times help ensure undiluted driving pleasure for drivers with dynamic inclinations. A short dab of the gearshift paddles is all it takes to change gear – up with the right hand, down with the left. The driver can see the gear currently engaged on a display in the AMG instrument cluster. The CLK DTM AMG can also be driven in fully automatic mode, underlining its impressive practicality.
Totally new spring and shock absorber units with adjustable coil springs ensure remarkably precise driving characteristics
AMG’s vast reserves of motorsport expertise are equally as evident in the chassis set-up of the CLK DTM AMG as they are in the powertrain. Height-adjustable spring and shock absorber units with adjustable coil springs replace the conventional coil spring/shock absorber units in the standard CLK, allowing the vehicle height to be adjusted extremely precisely. The rear axle is fitted with totally new spring links and strengthened hub carriers, resulting in improved traction and optimised durability. A harder setting for the rear-axle anti-roll bar cuts the car’s roll angle through fast corners and all the chassis’ rubber elements have been strengthened. The dampers are attached to the body by means of uniball elements. A trusted feature of modern racing cars, this technology allows particularly precise handling. Reinforced drive shafts are fitted in response to the car’s increased power. The multiple-disc limited-slip differential on the rear axle ensures optimum contact between wheels and road. This system works in the same way as its equivalent in the DTM racing touring car and generates a locking factor of 60 percent under acceleration and 40 percent under deceleration. In the interests of optimising strength, the rear axle drive is fitted with a separate oil cooler. All driving dynamics control systems, such as Acceleration Skid Control (ASR) and the Electronic Stability Program (ESP®), have been adjusted and newly developed in response to the modified chassis set-up and the increased output and torque of the new car. ESP®, which can be switched off to allow a certain amount of oversteer, further enhances the outstanding agility and unrivalled driving dynamics of the CLK DTM AMG.
Sports tyres from DTM partner Dunlop offer excellent grip
The sports tyres available as an option for the CLK DTM AMG open the door to cornering speeds normally only possible in racing cars, with transverse acceleration calculated at 1.35 g. The Super Sport Race tyre produced by DTM partner Dunlop in conjunction with Mercedes-AMG offers outstanding grip on account of its special rubber compound and asymmetric tread. Fitted on multi-piece AMG light-alloy wheels specially developed for the CLK DTM, they present a harmonious image – 255/35 R 19 tyres are fitted on nine-inch-wide rims at the front axle, 285/30 R 20 tyres combine with 10 x 20-format rims at the rear. The wheels sit flush with the car’s wings and provide a snug fit inside the wheel arches.
Large composite brakes display remarkable strength
Flawless responses, impressive sensitivity and unrivalled strength are the principal attributes of the newly developed AMG high-performance composite braking system. This technology, based on axial and radial connections between the grey cast iron discs and aluminium bowls, has the advantage of cutting weight by some 20 percent and increasing heat resistance. All discs are internally ventilated and perforated. The front axle is equipped with 360 x 32-millimetre discs and six-piston fixed callipers, the rear axle fitted with 330 x 26-millimetre discs and four-piston fixed callipers. The standard Brake Assist system has been adjusted according to the characteristics of the new braking system.
Interior with the functional style of a racing touring car
The inside of the Mercedes-Benz CLK DTM AMG is likewise a testament to the car’s racing heritage. Opening the door, the driver is greeted by a functional, predominantly black interior with an array of trim elements in the carbon-fibre-reinforced material CFRP. Refined matt aluminium-look touches lend the interior ambience the dash of exclusivity you would expect from an AMG high-performance car. The CFRP AMG sports bucket seats have leather trim and team up with the four-point safety belts to provide unrivalled lateral support for the driver and passenger. The sports pedals and AMG racing steering wheel offer optimum control over the vehicle, whilst the oval, powerfully formed steering wheel rim is trimmed in high-grip suede. Added to which, the driver can use two buttons integrated into the steering wheel spokes to access information on the trip computer.
New AMG instrument cluster with LED rev counter
The new AMG instrument cluster is attractively styled and clearly laid out, and features a 360 km/h-dial and integrated LED rev counter. A total of 64 light-emitting diodes display the engine speed, their colour changing from white to red when the driver approaches the maximum 7000 rpm. The gear change required at this time is also indicated. These two displays are joined by a series of instruments – set in carbon-fibre composite – which show the coolant, transmission and engine oil temperature, fuel supply and gear currently engaged and thus also serve as a reliable source of information for the driver. Likewise constructed in CFRP, the centre console stands out with totally new styling. In front of the close-at-hand selector lever are the engine starter button and four rocker switches for functions including the shift program, ESP®, anti-theft alarm and trip computer. The vehicle number provides a reminder, if such were needed, of the exclusive status of this, one of a limited edition of only 100 units. Included in the list of standard equipment are bi-xenon headlamps, THERMATIC automatic climate control, KEYLESS-GO and the Audio 50 APS CD/radio system with navigation function. It goes without saying that additional equipment options can be incorporated into the high-performance AMG Coupé in the highly specialised AMG workshop. The Mercedes-Benz CLK DTM AMG will be built by hand as part of a close coopera-tion between Mercedes-AMG GmbH and H.W.A. GmbH. One of the most successful touring car racing teams of all time, H.W.A. GmbH is also responsible for the development and running of the new C-Class DTM cars. The first examples of the 100-unit limited-edition CLK DTM AMG will be delivered to customers from autumn 2004. Mercedes-AMG GmbH is responsible for marketing, sales and service activities relating to the new car.

Development and testing

Proving its mettle in the �Green Hell�
  • Over 20,000 kilometres of testing on various race circuits
  • A further 30,000 kilometres of extended road testing under everyday conditions
  • Development work in the wind tunnel focuses on aerodynamic fine-tuning
It was during the highly successful 2003 DTM season, in which Bernd Schneider drove his CLK to the drivers’ title, that plans were drawn up for a road-going Mercedes-AMG off-shoot of the race-specification car. The brief was to create an AMG masterpiece whose styling and driving characteristics were both modelled on the championship-winning car in the popular touring car series. With an outline design brief on the table, the team of engineers could begin their work. The first stage of the project involved building a design prototype based on the Mercedes-Benz CLK 55 AMG and blending characteristic elements of the DTM race car into the silhouette of the standard production car. Various different variants were discussed, evaluated, produced and redesigned before, after exhaustive testing in the wind tunnel, the team agreed on a conclusive design.
Exacting test bench programme for the AMG 5.5-litre V8 supercharged engine
At the same time, the engineers and technicians were working on the construction and testing programme for the AMG 5.5-litre V8 supercharged engine, AMG SPEEDSHIFT drive system and the new chassis. The 428 kW/582-hp AMG eight-cylinder power unit was first subjected to several tests on the test bench. These included carrying out analysis of the basic mechanical functions, inspections of the oil and water circuits and checks of the low-temperature water circuit, as well as advancing through the various different development variants of camshafts, and intake airflow, charge pressure and electronic engine management systems. The knowledge gained from this round of testing served as a constant point of reference in the further development of the different engine components, which started life as hand-made prototype parts. At a later stage, the ready-for-production components could then be put through various extended tests in order to ensure a high level of quality.
Bernd Schneider, Klaus Ludwig and Markus Winkelhock take on the role of test drivers
The first ready-to-drive prototype of the CLK DTM AMG lined up shortly afterwards and made its debut appearance on the Hockenheimring race circuit. Current DTM drivers Bernd Schneider and Markus Winkelhock took it in turns with former Mercedes-Benz pilot Klaus Ludwig to take the wheel of the fledgling car. The professional drivers were immediately impressed by the potential of the AMG Coupé and supplied the engineers and technicians responsible with some valuable feedback on the engine, AMG SPEEDSHIFT automatic transmission, chassis set-up and brakes. A further wave of development models were produced back in Affalterbach and sent out on test tracks and race circuits to prove their mettle. The Nürburgring Nordschleife and the Hockenheimring in Germany were joined on the schedule by the Jerez circuit and Idiada test track in Spain, with the CLK DTM AMG given an exacting workout and subjected to some thorough inspections. On many occasions, it shared the spotlight with the new C-Class racing touring car, which was undergoing preparations for the 2004 season in the DTM.
Endurance test on the Nürburgring’s legendary Nordschleife circuit
The toughest test of all was undoubtedly the challenge posed by the Nürburgring’s Nordschleife circuit. Completed in 1927, the legendary race-track subjected the car and its constituent components to the sternest possible examination. 20.8 kilometres of blind crests, long straights, inclines and descents, as well as corners of every conceivable radius have earned the Nordschleife a reputation as the world’s most demanding circuit – and the nickname �the Green Hell�. The sudden changes in weather for which the Nordschleife is famous were a constant companion for the test drivers as they worked on the settings for the chassis, brakes, tyres, ESP® and ASR. Sporadic rain showers played havoc with the friction coefficient of the road surface, inadvertently creating the ideal conditions for the development of the CLK DTM AMG. The test car had to complete a total of some 10,000 kilometres of full-load testing on the Nürburgring.
30,000 kilometres of extended testing on a range of roads under everyday conditions
In addition to the total of 20,000 kilometres of testing clocked up on the various race-tracks, the development programme also included 30,000 kilometres of trials on a range of different public roads. In line with the standardised DaimlerChrysler endurance testing guidelines, the CLK DTM AMG had to reel off a precisely defined series of tests in city traffic, country roads and motorways. All with the aim of checking and fine-tuning the car’s components under everyday conditions. The countless kilometres of testing had left the experienced track stars in no doubt that the extensive development and testing programme for the Mercedes-Benz CLK DTM AMG had been worthwhile. �This high-performance road car exceeds even the highest expectations,� beamed Klaus Ludwig, the three-time Le Mans victor, triple DTM champion and FIA-GT Championship winner, who has been working for DaimlerChrysler and Mercedes-AMG as a consultant to the development engineers since his retirement from motor racing. Bernd Schneider, the current ITC champion, FIA-GT Championship winner and four-time king of the DTM, was similarly effusive: �The CLK DTM AMG is the best street racer I’ve ever driven�.
Technical data

The Mercedes-Benz CLK DTM AMG

Engine

No. of cylinders/arrangement

 

8/V, 3 valves per cylinder

Displacement

cc

5439

Bore x stroke

mm

97.0 x 92.0

Rated output

kW/hp

428/582 at 6100 rpm

Rated torque

Nm

800 at 3500 rpm

Maximum engine speed

rpm

7000

Compression ratio

 

10.5 :1

Mixture preparation

 

Microprocessor-controlled injection system, supercharger

Power transmission

Transmission

 

Five-speed automatic
with SPEEDSHIFT

Gear ratios

Final drive

1st gear

2nd gear

3rd gear

4th gear

5th gear

Reverse

3.06

3.59

2.19

1.41

1.00

0.83

3.17

Chassis

Front axle

McPherson three-link front suspension, anti-dive device, spring and shock absorber units with adjustable coil springs and gas-filled shock absorbers, anti-roll bar

Rear axle

Multi-link independent suspension, anti-squat and anti-dive device, spring and shock absorber units with adjustable coil springs and gas-filled shock absorbers, anti-roll bar, multiple-disc limited-slip differential

Braking system

Hydraulic dual-circuit braking system with vacuum booster and Brake Assist, composite disc brakes front and rear internally ventilated and perforated, ABS, ESP®, foot-operated parking brake rear

Steering

Rack-and-pinion power steering, steering shock absorber

Wheels

Front: 9 J x 19; rear: 10 J x 20

Tyres

Front: 255/35 R 19; rear: 285/30 R 20

Dimensions and weights

Wheelbase

mm

2722

Track width front/rear

mm

1569/1580

Overall – length

mm

4650

Overall – width

mm

1800

Overall – height

mm

1360

Kerb weight, EU

kg

1748

Payload

kg

280

Perm. gross vehicle weight

kg

2028

Tank capacity/of which reserve

l

92/12

Performance and fuel consumption

Acceleration 0-100 km/h

s

3.9

Maximum speed

km/h

320**

Fuel consumption NEDC comb.

l/100 km

13.7

* according to VDA method; ** electronically governed