SuperCarNews
Home News Wallpapers Contact Links

Mercedes-Benz McLaren SLR

Mercedes-Benz McLaren SLR 001
Mercedes-Benz McLaren SLR 002
Mercedes-Benz McLaren SLR 003
Mercedes-Benz McLaren SLR 004
Mercedes-Benz McLaren SLR 005
Mercedes-Benz McLaren SLR 006
Mercedes-Benz McLaren SLR 007
Mercedes-Benz McLaren SLR 008
Mercedes-Benz McLaren SLR 009
Mercedes-Benz McLaren SLR 010
Mercedes-Benz McLaren SLR 011
Mercedes-Benz McLaren SLR 012
Mercedes-Benz McLaren SLR 013
Mercedes-Benz McLaren SLR 014
Mercedes-Benz McLaren SLR 015
Mercedes-Benz McLaren SLR 016
Mercedes-Benz McLaren SLR 017
Mercedes-Benz McLaren SLR 018
Mercedes-Benz McLaren SLR 019
Mercedes-Benz McLaren SLR 020
Mercedes-Benz McLaren SLR 021
Mercedes-Benz McLaren SLR 022
Mercedes-Benz McLaren SLR 023
Mercedes-Benz McLaren SLR 024
Mercedes-Benz McLaren SLR 025
Mercedes-Benz McLaren SLR 026
Mercedes-Benz McLaren SLR 027
Mercedes-Benz McLaren SLR 028
Mercedes-Benz McLaren SLR 029
Mercedes-Benz McLaren SLR 030
Mercedes-Benz McLaren SLR 031
Mercedes-Benz McLaren SLR 032
Mercedes-Benz McLaren SLR 033
Mercedes-Benz McLaren SLR 034
Mercedes-Benz McLaren SLR 035
Mercedes-Benz McLaren SLR 036
Mercedes-Benz McLaren SLR 037
Mercedes-Benz McLaren SLR 038
Mercedes-Benz McLaren SLR 039
Mercedes-Benz McLaren SLR 040
Mercedes-Benz McLaren SLR 041
Mercedes-Benz McLaren SLR 042
Mercedes-Benz McLaren SLR 043
Mercedes-Benz McLaren SLR 044
Mercedes-Benz McLaren SLR 045
Mercedes-Benz McLaren SLR 046
Mercedes-Benz McLaren SLR 047
Mercedes-Benz McLaren SLR 048
Mercedes-Benz McLaren SLR 049
Mercedes-Benz McLaren SLR 050
Mercedes-Benz McLaren SLR 051
Mercedes-Benz McLaren SLR 052
Mercedes-Benz McLaren SLR 053
Mercedes-Benz McLaren SLR 054
Mercedes-Benz McLaren SLR 055
Mercedes-Benz McLaren SLR 056
Mercedes-Benz McLaren SLR 057
Mercedes-Benz McLaren SLR 058
Mercedes-Benz McLaren SLR 059
Mercedes-Benz McLaren SLR 060
Mercedes-Benz McLaren SLR 061
Mercedes-Benz McLaren SLR 062
Mercedes-Benz McLaren SLR 063
Mercedes-Benz McLaren SLR 064
Mercedes-Benz McLaren SLR 065

Mercede-Benz McLaren SLR

INTRODUCTION

The Mercedes-Benz SLR McLaren marks a new era of Mercedes-Benz passion for high-performance sports GT cars and, at the same time, celebrates the formidable SLR race cars of the 1950s. A futuristic interpretation of styling elements from the original 1955 Mercedes-Benz 300SLR roadster, the legendary SLR “Uhlenhaut Coupe” and the latest Formula One Silver Arrow race cars bridges the past and future, bringing cutting-edge motorsports-inspired design to the road.

Not only does the new SLR boast a rich heritage, but the new sports GT car also has an exciting future as a flagship within the multi-dimensional Mercedes-Benz brand. With by far the broadest product portfolio of any luxury automaker, Mercedes-Benz offers an array of models ranging from mid-size coupes to large premium sedans and wagons as well as sport utilities, luxury roadsters and now the limited-production SLR.


A Mercedes-Benz and McLaren Collaboration

The new SLR super sports GT car showcases the collective experience of Mercedes-Benz and its Formula One racing partner McLaren in the development and production of high-performance sports cars. This unique combination of expertise is evident not only in the impressive performance and pioneering developments of the new SLR, but also in its high levels of safety and practicality.



617-Horsepower V8 Powerplant

A front-mid-engine V8 producing 617 horsepower rockets the new SLR from zero to 60 miles per hour in under 3.8 seconds, and its top speed is over 207 mph. Stopping the car is equally quick, thanks to ceramic brake discs and an innovative air brake – an adaptive rear spoiler in the trunk lid. When the driver hits the brake pedal above 59 mph, the spoiler or wing pops up at a 65-degree angle, increasing air drag and providing greater down force.


AMG Supercharged Power

Each supercharged SLR engine is hand built at AMG’s manufacturing facility in Affalterbach, Germany. The engine’s dry-sump lubrication system (originally developed for race cars to prevent oil starvation during extremely hard cornering) includes a remote oil tank that eliminates any conventional oil pan or sump, allowing the engine to be mounted lower in the frame for better aerodynamics and an even lower center of gravity. The powerplant is also mounted in a front mid-engine position – behind the front wheels.


Carbon Fiber Body

One dramatic example of technology transfer from Formula One racing is the carbon fiber composite construction of the SLR body, which provides rigidity and strength never before achieved in road-going vehicles. Equally impressive is its high level of occupant protection. In a serious collision, specially designed crash structures of carbon fiber help the new super sports GT car absorb over four times more crash energy than convention steel or aluminum.



Ceramic Brake Discs

The ceramic brake discs on the SLR are made of a new composite material – a carbon fiber-reinforced ceramic that boasts astounding stopping power, high heat resistance, outstanding structural strength and long service life. The high-performance SLR is one of very few production cars to make use of ceramic brake technology. Fitted with huge eight-piston calipers up front, the brake system alone can decelerate the SLR up to 1.3 g, and the air brake or adaptive rear spoiler adds to the brake force, especially at high speeds.


Reinventing the SLR Legend

The first SLR was one of the most successful sports racing cars of all times, and like the new car, the SLR of the 1950s combined leading-edge technology from the SL sports car and the Mercedes-Benz Formula One race car. Its three-liter, straight-eight engine made 310 horsepower, pushing the 300SLR to speeds of around 190 miles per hour.

The original SLR’s most astonishing feat took place at the 1955 Mille Miglia -- at the time a no-holds-barred race through Italy over twisty public roads. Setting a record never to be matched, Stirling Moss and Dennis Jenkinson piloted the 300SLR over the 1000-mile road course in 10 hours, seven minutes and 48 seconds!

The Uhlenhaut Coupe

Perhaps the purest roots of the new SLR can be traced back to the legendary Uhlenhaut Coupe. Head of both passenger and race car development at Mercedes-Benz in the 1950s, Rudolph Uhlenhaut built two street-car prototypes of the formidable race car, but the coupe versions never went into production. The 300SLR coupe – known to car enthusiasts as the “Uhlenhaut Coupe” – incorporated some of the design and technology from the 300SL Gullwing with the 300SLR roadster. Weighing less than 2500 pounds and boasting 310 horsepower, the Uhlenhaut Coupe had a top speed of about 180 miles per hour, making the two-seater the fastest street-legal car of its time.



SLR ENGINE



Prodigious power and high-tech features drawn from the racing world – these qualities define the first V8 developed exclusively by Mercedes-AMG. Their engineers meshed the high standards of the Mercedes-Benz brand with their 30 years of motorsports experience. The culmination of their initial analysis encompassing a wide range of engine designs, they settled on a 90-degree V8 displacing 5.5 liters and using a screw-type supercharger.

The bottom line is impressive – from a mere 1,500 rpm, the SLR powerplant delivers over 440 foot-pounds of torque, which builds to well over 500 ft.-lbs. at 2,000 rpm. Its maximum torque of 575 ft.-lbs. begins at 3,250 rpm and continues undiminished to 5,000 rpm. This muscular torque curve (or plateau) plus agile throttle response and a peak output of 617 horsepower at 6,500 rpm make it one of the most powerful production engines in a modern street car.



First, Let’s Squeeze the Intake Air

The SLR engine makes use of a mechanical supercharger – essentially an engine-driven air compressor – which pressurizes intake air for increased torque and horsepower. Unusually compact, the SLR supercharger unit is nestled between the two banks of the V8 powerplant and features two screw-type aluminum rotors that are Teflon-coated for low friction and high air pressurization. Driven by the crankshaft via a poly-V belt, the Lysholm-type supercharger rotors can spin up to 23,000 revs per minute, forcing air into the engine at a pressure of 13 pounds per square inch or 0.9 bar. This means the supercharger pushes about 40,000 pounds of air per hour into the engine, up to 30 percent more than other such systems!



Then We’ll Cool It Off

Pressurizing the engine intake air makes it hot and reduces its density, so the super-charged air passes through two intercoolers – one for each cylinder bank – on its way to the engine. The water-cooled intercoolers act as radiators to cool off the hot air and keep it dense, increasing the amount of oxygen and ensuring top power.

The intercoolers have their own dedicated water circuit, completely separate from the conventional cooling system for the engine block and heads. All in all, the power of the SLR requires an ample cooling system for the engine as well as good cooling for its supercharged intake air. As a result, the car incorporates generous air inlets (and outlets) and a strong 850-watt suction type fan.



High-IQ Engine Management

AMG engineers developed a smart engine management system that manages the operation of the supercharger based on engine speed and load. For example, when the car is coasting, the supercharger is not driven by the engine. However, as soon as the driver steps on the gas pedal, the system engages a special electro-magnetic clutch, and instantly the supercharger is spinning. Because the air is pressurized in a fraction of a second, even the most discerning driver doesn’t notice the transition to supercharged power.

At light throttle or part load, when pressurized air isn’t needed but the supercharger is still spinning, an air recirculation flap opens, routing pressurized air back to the un-pressurized side of the intake air circuit. This reduces the force required to turn the supercharger rotors and improves fuel economy.



A Bulletproof Bottom End

AMG engineers applied their extensive racing experience and expertise in designing high-performance engines to many details of the SLR powerplant. The entire engine block is cast aluminum, with special reinforcing ribs as well as cylinder walls made of NiCaSil. The dynamically balanced crankshaft runs in five main bearings made of a durable long-life plastic. Forged connecting rods and pistons are sorted in carefully balanced sets for smooth high-speed operation, and dual oil-spray jets in the block help cool the back of each piston.



Dry Sump Makes A Low-Profile Engine

Conventional engines use a single oil pump that pulls lubricating oil out of a reservoir (or sump) in the bottom of the block and supplies it to all the bearings throughout the engine. However, the SLR has an unusual dry-sump lubrication system, again based on experience gathered in the racing arena. The SLR system uses two oil pumps. A five-stage suction pump keeps the bottom of the engine block “dry” and a two-stage pressure pump supplies all the bearings. Between the two pumps is a ten-quart oil tank that serves as a reservoir.

Dry-sump systems were originally developed for racing to prevent the engine-killing oil starvation that can occur with conventional wet-sump systems when oil sloshes to one side of the block during hard cornering, acceleration or braking. Dry sump systems also increase horsepower noticeably by reducing the usual drag created when a crankshaft churns in thick oil.

Without the usual sump (or pan) hanging below the block, the dry-sump engine could be mounted lower in the SLR body. This important benefit of a dry-sump oil system means a lower center of gravity for better handling, not to mention a lower hood line for improved aerodynamics and high-speed stability.





Twin-Plug, Three-Valve Architecture

The SLR engine makes use of innovative cylinder-head architecture that features two spark plugs and three valves for each cylinder. The three-valve layout allows the largest possible valve size that will still leave room for two spark plugs. Two intake valves feed the fuel-air mixture to each combustion chamber, and combustion heat in each of the large, single exhaust valves is dissipated through sodium‑filled valve stems.

Each cylinder head houses a single, hollow camshaft driven by double roller chains and silent, rubber‑coated sprockets. Twin rocker shafts in each head hold low‑friction, roller‑tip aluminum rocker arms to actuate the valves, and housed in the end of each rocker arm is a small hydraulic lifter that ensures quiet, maintenance‑free valve operation.



Two Spark Plugs for a Cleaner Burn

Using a single exhaust valve in each combustion chamber makes room for two spark plugs per cylinder. Mercedes’ innovative alternating, twin‑plug ignition system matched to the new three‑valve technology actually improves performance.

Among other things, the twin-spark system fires one plug after the other in quick succession and with varied “stagger,” depending on engine load and speed. This firing sequence (as well as the basic ignition timing) changes after each combustion cycle for extremely precise combustion control. This also enables close control of combustion chamber pressures to minimize noise without sacrificing efficiency. The twin-spark ignition allows an extremely lean air-fuel mixture and late ignition timing during warm‑up (retarded by 5‑10 crank degrees compared to a single-plug design), to further increase exhaust gas volume and temperature.



Modular Camshafts Reduce Weight

AMG engineers designed special high-tension valve springs and light-weight modular camshafts. To make the modular cams, AMG starts with a precision seamless welded tube. Individually forged cam lobes are placed onto the tube. When all cam lobes are lined up, an expansion lance is pressed into the tube. The lance expands the tube hydraulically at each lobe position, fusing the lobes to the shaft. This modular process simplifies the design and manufacture of camshafts.



More Than Just Side Pipes

The SLR exhaust system features four catalytic converters – two on each side – and secondary air injection, which together ensure extremely low exhaust emissions. After the main converter housing, exhaust flows into a muffler located just behind each front wheel. The mufflers (each over five gallons in volume) are designed for low exhaust back pressure and consist of precisely calculated acoustic sections that produce the characteristic SLR engine sound.

The exhaust exits via a pair of 2½-inch stainless-steel pipes on each side of the car. Another reminder of the 1950s racer, the side pipes allow the underside of the car to be entirely smooth, which plays a crucially important role in the car’s excellent aerodynamics and high-speed stability.



One Man, One Engine

Like all AMG engines, the SLR powerplant is assembled by hand in Affalterbach, Germany; and it’s then shipped to Woking, England for installation into the car. Each complete motor is the responsibility of one AMG engineer, who handles everything from bolting the crankshaft into the block to assembling the camshafts and installing the electrical wiring harness. Mercedes-AMG feels that the principle of “one man, one engine” is key to ensuring top-quality high-performance engines. Symbolic of this unusual commitment, every engine comes with a plaque mounted on the intake manifold that’s signed by the engineer who assembled it.



Dual Fuel Tanks

The SLR engine draws its fuel from two low-slung, inter-connected fuel tanks – a layout that also contributes to the car’s low center of gravity. The dual tanks are located on each side of the rear suspension and have a total volume of 25.8 gallons.

The tanks are equipped with two high-pressure electric fuel pumps that are controlled by the engine management system. To ensure that the fuel supply matches the needs of the engine, one pump runs all the time, while the second is activated only as needed, based on engine load and speed.



SLR Transmission

The Mercedes-Benz five-speed automatic transmission and rear final-drive unit, already used successfully in several high-performance models, have been further modified to handle the high torque of the SLR engine.

In addition to beefing up the gear housings and torque converter, gears in the center and rear planetary sets have been widened by five millimeters (about 0.2 inches), and the front planetary gears are two millimeters wider. While the wider gear teeth are stronger, this also makes room for larger bearings. What’s more, the hydraulic clutches that drive and lock the planetary sets in each gear range operate at higher pressures.

The transmission oil cooler is larger than on other Mercedes-Benz high-performance models, and a separate oil cooler just for the rear differential/final drive unit is mounted under the trunk floor. Air flows through this cooler from a triangular NACA duct in the otherwise flat underside of the car and exits through a grill between the back-up lights.



A New Level of SpeedShift

The Mercedes-AMG Speedshift system offers even more features in the new SLR. A knob on the left side of the center console offers a choice of three settings: “Comfort,” “Sport” or “Manual,” and each setting is identified in the instrument cluster display by the letter “C,” “S” or “M.” While the two automatic shift programs are similar, “Sport” provides higher-rpm shift points and crisper shifts.

In the “Manual” setting, the driver can shift either with buttons on the steering wheel or by using the side-to-side Touch Shift feature on the shift lever. Within the “Manual” setting, another knob on the right side of the console can select any one of three modes of progressively sportier shifting:



· Stage I – “Sport”

· Stage II – “SuperSport”

· Stage III – “Race”



In the sequence shown here, the shift response and transmission shifting speed become increasingly shorter.



SLR SUSPENSION





The SLR suspension features double forged-aluminum wishbones at all four corners. Its suspension design bears the signature of experienced race car developers and has been designed for excellence in three key areas: handling agility, active safety and comfort.



Negative Camber is Positive

Light unsprung weight is a distinct advantage, and in the case of the SLR, its aluminum suspension, stub axles and wheels as well as the super-lightweight ceramic brake discs all work together for extremely fast and sensitive handling response. The cutting-edge brake discs weigh just 13 pounds each, 21 pounds less than conventional brake discs. Its relatively long wheelbase (106.3 inches), wide track (64.5 inches) and low center of gravity also contribute to the car’s great handling, especially when cornering at speed.

As the suspension compresses, especially when cornering at high speed, the SLR wishbone geometry provides the wheels with slight negative camber for the best possible tread contact. At the same time, the rear suspension is designed with anti-squat characteristics on acceleration, and the front suspension layout minimizes dive during hard braking.



Formula One Stabilizer Bar

The front stabilizer bar is above the front suspension and is connected to the suspension by rocker-arm linkage – as in Formula One race cars. This layout means that the stabilizer bar does not break up the car’s smooth underbody, which is vitally important for its outstanding aerodynamics and high-speed stability.



SLR STEERING

Fast-ratio rack-and-pinion steering with speed-sensitive power assist makes for precise, lightening-quick reflexes. Located in front of the engine, the lightweight steering gear unit has a ratio of 12.6, which gives drivers the impression that the car goes wherever the 15-inch steering wheel is pointed! The wheel is electrically adjustable for reach (2 ½ inches) and tilt (2.7 degrees).



SLR BRAKES

The high-performance SLR is one of very few production cars to make use of ceramic brake technology, a result of DaimlerChrysler materials research and Mercedes-AMG experience with high-tech brakes on the street and track.



Carbon-Fiber Ceramic Brake Discs

The brake discs on the SLR are made of a new composite material – a fiber-reinforced ceramic that boasts astounding stopping power, high heat resistance, outstanding structural strength and long service life. Carbon fiber, powdered carbon and resin are pressed into shape at high pressure during manufacturing and baked with a silicon compound at around 2700° Fahrenheit to form the ceramic. The benefits of ceramic brake discs are impressive:

· The discs are temperature-resistant up to 1800°, which means high-speed fade resistance never before achieved in a production car.
· Although they’re over 14 inches in diameter, the SLR discs are less than half the weight of conventional steel discs – 13 pounds instead of 34.
· The brakes can decelerate the SLR up to 1.3 g. The braking system’s theoretical strength is 2000 horsepower!
· For most owners, the SLR ceramic brake discs will last the life of the car.



Brake calipers on the SLR are specially designed to take advantage of the ceramic discs. Eight-piston fixed calipers are used on each front wheel and four-piston on the rear. Total brake pad area at the front end alone is 68.2 square inches, which contributes to outstanding braking. For example, the stopping distance from 62 mph is only 114 feet.



An Air Brake Helps Slow Things Down

An adaptive rear spoiler built into the trunk lid adds to the outstanding braking of the SLR. If the driver hits the brake pedal hard enough, the spoiler automatically flips up at a 65-degree angle, producing more than 300 pounds of extra downforce to make the brakes even more effective. At about 60 mph, the spoiler automatically rises to 10 degrees, and the driver can control the airbrake via a switch on the console up to an angle of 30 degrees.



SLR WHEELS AND TIRES

On U.S. models, “staggered” 19-inch turbine-style alloy wheels and tires are standard equipment, while 18-inch wheels are a no-cost/no-credit option for customers who prefer a different look (a choice of two styles – five-spoke and ten-spoke) or a taller tire sidewall.


The first two dimensions – tire width and sidewall height – are listed in millimeters, while the remaining dimensions are shown in inches. This industry convention includes expressing sidewall height as a percentage of the width. For example, the standard front tire is 255 mm wide (around 10 inches), and its sidewall height is 35 percent of that – about 3 ½ inches.



Tire Pressure Monitoring

The SLR comes with a tire monitoring system that has pressure sensors built into the inside end of each tire valve. As the wheels spin, the information is transmitted by radio to antennas inside each wheel well. The signals are processed by a central control unit that can distinguish the signals from each wheel, and information on each wheel is shown on a central display in the cockpit.



ESP Stability Control

ESP electronic stability control and SBC electronic braking are integral parts of the SLR’s safety and dynamic handling systems. Since the electronic braking system uses a high-pressure accumulator to hold brake fluid at a pressure of 2,000 to 2,300 pounds per square inch, this power means that the ESP system works even better than on ESP-equipped models with conventional brakes. Thanks to even faster and more finely metered brake impulses from the high-pressure accumulator, ESP can stabilize a skidding vehicle at an earlier stage.

Engineers developing the SLR thought it might be a challenge to adapt the stability control system to the car’s distinctly sporty performance while maintaining their usual safety standards. However, with its sophisticated sensors and light-speed reactions combined with sheer braking power, the presence of the electronic braking system actually made it easier to fine-tune ESP for a very sporty driving style that allows moderate oversteer and understeer without throttle intervention when driving the SLR, but without compromising active safety.

Mercedes-Benz invented ESP stability control in the 1990s and debuted the system on its more expensive 1996 models in the U.S. The high-tech feature is now standard equipment on all models.



ESP Works Like a Mind Reader

ESP calculates every microsecond if the car is going exactly in the direction it is being steered. If there’s an appreciable difference between what the driver is “asking” – through the steering wheel – and what the vehicle is doing, the system corrects with split-second speed by applying one of the left or right-side brakes, even before the driver may sense any changes.

ESP uses steering wheel angle and wheel speed to calculate the path being steered, and it gets signals about lateral “g” forces and “yaw” to measure what the car is actually doing. (Imagine turning a model car on a toothpick stuck down through the roof – that’s yaw!)

Whenever it senses understeer, ESP increases brake pressure to the inside rear wheel. With an oversteer tendency, it increases brake pressure to the outside front wheel. Unlike traction control, ESP is effective during acceleration, braking and coasting. The system enhances driver control and helps maintain directional stability in turns as well as when driving straight-ahead, including on uneven surfaces and over patchy snow, ice or gravel.



Electronic Braking

In the SBC electronic brake system – another Mercedes-Benz invention – light-speed electronics replace many of the mechanical and some of the hydraulic parts. A powerful micro-computer oversees the system’s operation by processing information from a series of sensors and control units.

The pedal is no longer connected hydraulically to the wheels (except for a backup system that operates the front wheels conventionally in the unlikely event of an electronics problem). The brake pedal and master cylinder are merged into a single operating module (a conventional vacuum-powered brake booster isn’t needed), and this module primarily transmits brake commands to the microcomputer via electronic impulses.


The Nerve Center – Electronic and Hydraulics Working Together

The centerpiece of the electronic braking system brings together the microcomputer, wheel pressure modulators, a hydraulic pressure reservoir and an electrically-driven hydraulic pump. The operation of this assembly highlights the interdisciplinary beauty of the system – while hydraulics still provide the sheer braking power, electronics make it work faster and better than ever:



1. The electronic braking microcomputer calculates exactly the right brake force for each wheel by processing signals from the pedal unit and from sensors all over the car. It considers wheel speed data from the ABS system, steering angle and cornering g-forces from the ESP system, as well as signals about the engine braking effect and which gear is engaged from the engine-transmission microcomputers. The result of these complex calculations is instantaneous brake commands, which means maximum braking and driving stability.



2. The high-pressure reservoir holds the hydraulic oil or brake fluid that powers the system under 2,000-2,300 pounds per square inch of pressure. The microcomputer controls an electric pump and regulates hydraulic pressure throughout the system. The overall result is much shorter response times compared to conventional brake systems. This system also provides full braking power even when the engine is off.



3. Four wheel pressure modulators regulate brake pressure at each wheel based on everything processed by the microcomputer. Each wheel is braked individually to ensure the greatest possible driving stability and optimal deceleration. A pressure sensor for each wheel modulator, for the reservoir and for the pedal unit helps the microprocessor to monitor everything.


Braking Around Corners Like Never Before

If braking is ever necessary in a turn, conventional systems apply the same brake pressure on the inside and outside wheels. However, the SBC electronic brake system increases pressure to the outside wheels and reduces it on the inside ones. This takes advantage of the vehicle’s natural weight transfer during cornering and increases vehicle stability, in part by reducing the tendency to lock the inside wheels when braking in turns. To provide this valuable left-right brake proportioning, the microcomputer processes signals from the ESP steering angle sensor and lateral G-force sensor.

In a similar way, front-rear brake proportioning is also part of the system’s built-in algorithm. To prevent dangerous over-braking on the rear wheels, the majority of the braking force is placed on the front wheels during high-speed braking. At low speeds and when braking lightly, the system places more of the braking pressure on the rear wheels, ensuring smoother response and more equal wear on the brake pads.


Built-in Brake Assist for Faster Emergency Braking

Among the greatest benefits of the Mercedes-Benz electronic braking system is the ability to respond to driver and vehicle behavior as well as make use of the extremely fast buildup of brake pressure.

If drivers switch their foot quickly from the accelerator to the brake pedal, the electronic brake system recognizes the early signs of an emergency situation and reacts accordingly. First, the microcomputer “primes” the system by raising brake pressure in the connectors and pressing the brake pads lightly against the disks.

As soon as the brake pedal is pressed, full-power braking is applied with the help of the high-pressure reservoir. In practical terms, this means that alerting the system and then applying full pressure shortens the stopping distance from about 80 mph by some three percent!


A Comfortable Pedal

To simulate the familiar pedal feel of conventional brakes, Mercedes engineers utilize the tandem hydraulic cylinder that operates the front brakes only in the event of an electronic failure. In normal operation, this master cylinder is hydraulically “decoupled” from the rest of the system.


Staying Dry in the Rain

Wet brake discs can mean a slight delay in braking – an instant of terror until the wheels make one turn and the brake pads squeegee a film of water from the disks. In wet weather, the electronic brake system provides short, imperceptible brake impulses to wipe off the water, ensuring fast brake response. This automatic drying feature works whenever the windshield wipers are on.




SLR BODY

The body of the Mercedes-Benz SLR McLaren is as high-tech as the rest of the car. Aerodynamic tests began with 1:3-scale models in the McLaren wind tunnel, where the contours of Formula One race cars are refined. Testing of full-size SLR prototypes in the wind tunnel at the University of Stuttgart involved detailed analysis of the airflow along and under the body. For example, while test car wheels normally stand still in wind-tunnel tests, the Stuttgart facility has two steel conveyor belts that drive the tires and help simulate all the real-world air flow conditions.

Familiar design features from Formula One, the SLR’s virtually smooth underbody with a six-channel diffuser and special spoilers at the rear as well as diffusers at the front all work together to ensure that negative lift or downforce is created, especially at higher speeds.



High-Tech Materials, Too

Most of the car is made of carbon fiber composite – the entire body shell, its gull-wing doors, the hood and underbody structures at the front and rear. Overall, the SLR is about 30 percent lighter than a comparable vehicle with conventional steel construction. The complete body shell with brakes and suspension parts weighs only 700 pounds!

While this extremely strong yet lightweight material originated in the aircraft and aerospace industries, carbon fiber has proven itself dramatically on the world’s top race tracks. As Formula One developers have begun using carbon fiber crash structures over the past several years, the F1 racing discipline has seen a dramatic reduction in serious injuries from accidents.



Half the Weight and Four Times the Energy Absorption

Carbon fiber is half the weight of comparable steel parts and 30 percent lighter than aluminum! What’s more, carbon fiber absorbs four to five times more energy than steel or aluminum in a collision.

Mercedes-Benz takes advantage of this extraordinary energy absorption by installing a two-foot longitudinal member made of specially designed carbon fiber on each side of the SLR front end. In a head-on collision, the fibers in these conical crash members shred from front to rear with absolutely consistent deformation, ensuring steady deceleration. With their ever-changing cross-section, the conical carbon-fiber crash members not only have predictable energy absorption but also a weight advantage, since the design uses only as much material as is actually needed. Each of the longitudinal members weighs only 7 ½ pounds.



The First Production Car with Carbon-Fiber Crash Structure

The carbon-fiber crash members are bolted to an aluminum sub-frame for the engine, and at the front, they connect to the body shell by means of a cross member and a flat sandwich panel, both made of carbon fiber composite. As a result, the SLR is the world’s first production car with a front crash structure made entirely of carbon fiber.

At the rear of the car, similar carbon-fiber crash members, along with a hefty cross member, handle energy absorption in the event of a rear impact. In a side impact, wide door sills with multi-piece elements of carbon fiber and aluminum protect the occupants.



Four Years of Careful Development Work

The goal of engineers from the Advanced Design department at the Mercedes-Benz Technology Center and from DaimlerChrysler Research was not only to design crash members with unprecedented passive safety, high strength and low weight, but also to develop the first automated manufacturing processes for carbon fiber. Prior to the SLR project, carbon fiber parts for race cars and airplanes alike have been made by hand – an extremely time-consuming process.

Early steps included the first-ever development of a special algorithm for calculating crash dynamics on carbon fiber. Sophisticated computer simulations were crucially important to fine-tuning the crash structure. At the same time, materials experts were testing the calculations by conducting precise drop-tests of carbon fiber models. Over a four-year period, design details of the SLR crash members were gradually defined.



The First-Ever Automated Production of Carbon Fiber

To transform the world of carbon fiber from slow hand work to automated production, Mercedes-Benz materials experts took a careful look at the textile industry. They ultimately took conventional production methods of sewing, knitting, weaving and braiding fabrics and adapted them for making high-performance carbon fiber.

For example, the web of the SLR’s front crash members is formed by laying several layers of carbon fiber on top of each other and sewing them together by machine. Then the piece is cut into shape, folded into a double-T profile and inserted in a plastic braiding core, which in turn is clamped into a special braiding machine. Each crash member is braided together with 25,000 extremely fine carbon filaments that are simultaneously unwound from 48 reels. This technology allows carbon fiber to be braided around the core at specific angles to create the right contour, and several layers are even laid on top of each other in certain areas to get the right thickness.

A computer-controlled tufting machine then joins the inner web to the braid of the longitudinal member, after which the plastic core is removed. Then the pre-formed crash member is trimmed to the correct size and injected with resin.

Several patented processes were developed to ensure good repeatability and short cycle time – critical factors for series production. Making the complex carbon-fiber structure of the SLR’s front crash members takes just 12 minutes, a clear demonstration of the potential offered by this innovative manufacturing technology.



SLR Uses Advanced Sheet Molding Compound Method

The rear shelf of the new SLR provides another example of new techniques used by Mercedes-Benz for producing carbon fiber components. Although it’s a complex shape with several openings, the rear shelf is manufactured in one piece using a new Advanced Sheet Molding Compound method.

A machine automatically positions several layers of carbon fiber composite in the basic shape, and under heat, this blank is pressed into the exact shape of the rear shelf. No further steps are needed. Mercedes-Benz is the first automaker to use components made by the Advanced SMC method.



McLaren Composites

The McLaren Composites company also manufactures more than 50 carbon fiber and fiberglass parts for the new high-performance sports GT car. The entire floor assembly, including all support members and securing points, is made in one piece, as is the roof frame, which is filled with foam before the resin is injected to create an especially crashworthy sandwich structure. High-strength bonding and riveting techniques connect the sections of the chassis and body shell.

An aluminum sub-frame for the engine mounts is bolted to a carbon fiber bulkhead and bonded in place as well. In the rear, steel mounts are bonded into the carbon fiber for the rear differential/final drive unit.

PASSIVE SAFETY

The world’s safest sports GT car features a carbon-fiber crash structure and a rigid passenger cell that’s distinct from the front and rear crumple zones. In addition, a cutting-edge restraint system with six air bags, seat belt tensioners and belt force limiters completes the safety picture on the SLR. In a frontal collision, the system first triggers the seat belt tensioners, which pull taut up to six inches of loose belt, limiting occupants’ forward motion. The belt tensioners are also activated if the car senses a rollover.



Smart Front Air bags Feature Two-Stage Deployment

In a more severe collision, two-stage front air bags also deploy. Two sophisticated sensors just behind the front bumper (on the radiator cross member) and one right in the passenger compartment (on the transmission tunnel) measure the severity of the impact, and an electronic control unit decides with lightning speed whether one or both chambers of the two-stage gas generators are triggered.

In a high-force collision, both stages are deployed, inflating the front air bags more quickly. The driver’s air bag has a volume of 2.26 cubic feet when inflated, while the passenger’s front air bag is 4.41 cubic feet. The passenger air bag is larger because of a wider possible range of occupant positions.



Knee Bags Help Out

At the same time as the front air bags, two knee bags deploy from the underside of the SLR dash, supplementing the protection provided by the seat belts and front air bags as well as reducing the natural tendency for occupants to “submarine” under the seatbelts.



Belt Force Limiters Fine-Tune the Protection

An instant after the belt tensioners have tightened the seat belts and the air bags have deployed, belt force limiters allow the belts to loosen slightly, to take full advantage of the fully inflated air bags’ cushioning effect and minimize the risk of chest or shoulder injuries from the belts.



Side Air bags for the Head, Neck and More

In a side impact, an air bag deploys from the door, ripping open a seam above the armrest and inflating in milliseconds. Sometimes referred to as a “head-thorax bag,” the SLR door-mounted side air bag is oblong when deployed so that it covers most of the side window. This design provides crucially important protection to the head and neck, not to mention shielding occupants from glass shards and other intruding objects in a collision.



Complete with Baby Smart

The passenger’s front air bag can be turned off by the standard-equipment BabySmart system if it senses the presence of a BabySmart-compatible child seat. Available in several sizes, BabySmart seats feature a built-in transponder that communicates with sensors in the seat upholstery. Without anyone having to operate a switch or connect any wires, the system automatically deactivates the large front air bag on the passenger side whenever the BabySmart seat is installed in the car. However, the seat belt tensioner and sidebag remain active, providing valuable protection to a young passenger in an accident.



SLR DESIGN

From first glance, the Mercedes-Benz SLR McLaren speaks the dramatic design language of today’s Formula One race cars blended with an echo of classic styling elements. The bold look of the Silver Arrow race cars that took the Mercedes McLaren team to Formula One World Championship glory is apparent in the stunning road car, and when the gullwing doors of the new SLR swing open, its historic connection to the 1955 Uhlenhaut coupe becomes even more obvious.



Gullwing Doors with an Avant-Garde Look

In their modern interpretation, the SLR’s gullwing doors swing up and forward from the front roof post – the “A” pillar – instead of directly from the roof as with the Mercedes-Benz gullwings of the 1950s. The new doors open at a 107-degree angle, providing a safer, larger door opening (for easier access to the interior) and creating an exciting, futuristic look.



Powerful Proportions Connect the Future and Past

The overall look of the new SLR features powerful proportions that start from a long, broad front hood, transition into a compact passenger cell and finish with a short trunk section. The centerpiece of the front hood is an arrow-shaped nose that’s reminiscent of the Mercedes McLaren Formula One race cars that won World Championships in 1998 and 1999.



An F1 Nose with a Twin-Fin Spoiler

Another distinctive F1 element can be found under the arrow-shaped nose – a twin-fin front spoiler that’s more than decoration. The fins create aerodynamic downforce that contributes to the car’s sure-footed, race-car-like handling. The fin motif is a recurring theme that helps create design consistency across the exterior of the SLR. Finned sections connect the headlights to the nose, support the side mirrors and adorn the wrap-around taillights, where 51 LEDs for the brake lights are housed in two fins, one above the other. Another 36 LEDs operate the turn signals. LEDs are brighter, last much longer and light up faster – about 150 milliseconds before conventional bulbs.



A Familiar Face Gets A Fresh Look

Above a large intake for engine cooling air, four elliptical headlights are arranged in a fresh treatment of the familiar face that has identified Mercedes-Benz cars for nearly a decade. On each side, two ovals form single units that house powerful xenon projection lights under clear covers that resemble high-quality camera lenses.

The headlights form a strong starting point for the lines of the hood and front fenders. The contours of the lights develop into sculpted curves along the hood that deliberately evoke images of an athlete’s sinewy muscles. These taut lines sweep back to the A-pillars, visually connecting the nose of the car to the passenger compartment.



A Strong Profile, Too

From the side, the eye is caught by the SLR’s flat, wedge-shaped profile. This shape is created by the long front hood, a steeply raked front windshield and short trunk section, which together emphasize the sense of forward tension throughout the new SLR supercar.

Just behind the front wheels, finned “gills” do much more than recall the design of Mercedes-Benz sports cars and racers from the 1950s. These stylized openings serve as vents for the all-important cooling air that exits the engine compartment, and under the gills, side pipes from the engine exit as well. The lines of the gills are accented by tapered fins that sweep back into the surface of the gullwing doors.



The SLR Interior Rocks

Inside the car, an obvious focal point is the center console, which is a visual extension of Formula One domes on the front hood. The console also picks up the lines of the front end as they flow over the transmission tunnel toward the back of the car. The upper console is dominated by the two knobs for transmission shifting modes, and below them, hidden under a neatly integrated aluminum cover, are controls for the Bose audio system, which can automatically adjust frequency response and sound level based on the amount of background noise. The dual climate control system considers signals from sensors for air quality, intensity of the sun and humidity.



A Cocoon of Aluminum, Leather and Carbon Fiber

An interplay of tactile materials creates a tasteful ambiance. Aluminum and carbon fiber contrast with supple leather that’s available in four color choices: Black, Orion Grey, Berry Red and the classic 300SL Red – the one color that uses extra soft “Silver Arrow” leather.

Another design borrowed from the racing world, one-piece carbon-fiber seats feature four different sizes of removable side bolsters that allow the buckets to be tailor-fitted. The seats are 25 percent lighter than conventional seats, and the bolsters allow the seat contours to be ergonomically adapted to each driver’s anatomy.

The two-tone interior uses dark leather on the dash to minimize reflections in the glass, while the seats, door panels and remaining interior trim are a contrasting lighter color. The entire headliner is finished in Alcantara, and the carpeting is pearl velour.

Inspired details abound: the speaker covers in the doors resemble the air outlets on the sides of the car, and the rear of the cover forms the door handle. However, a simple leather loop serves as a separate door pull – a traditional touch from the legendary Mercedes-Benz race cars.

A 15-inch three-spoke steering wheel comes with rocker switches to operate the multi-function display as well as push buttons for manual gear shifting. Looking through the wheel, cleanly styled chronometer gauges are positioned squarely in front of the driver. An 8,000-rpm tachometer shares center stage with a 220-mph speedometer, and they’re flanked by the requisite engine temperature and fuel gauges. A no-nonsense hand brake lever is nestled between the console and the passenger seat, and aluminum pedals with rubber studs finish the breathtaking interior.



And A High-Performance Trunk

The trunk of this high-performance sports GT car is surprisingly roomy, with 9.6 cubic feet of luggage space finished in leather and velour. Lift-up flaps provide easy access to compartments for the two batteries, windshield washer and brake fluid reservoirs, and the tool kit. This layout helps ensure even front-rear weight distribution and a low center of gravity.



In Conclusion

Combining unmatched supercar performance with surprising luxury and comfort, the SLR is destined to be a formidable competitor with revered brands from the other side of the Alps as well as the other side of Stuttgart. Unlike most of its direct competition, the SLR is equally at home on the way to the corner store, in city traffic, on twisty back roads and blazing down a race track at over 200 miles per hour.

As a result, the Mercedes-Benz SLR McLaren is changing the way people think about supercars. And, never before has there been such collaboration among a World Champion Formula One race team, a renowned boutique for high-performance cars and a global luxury car brand. McLaren, AMG and Mercedes-Benz are on their way to reshaping the world of exotic and super sports GT cars.

Source - Mercedes-Benz