A look at the BMW M-series and Mercedes AMG

March 17, 2016
With extensive racing backgrounds, BMW and Mercedes have also created a series of vehicles that share more with their race-driven brethren than that of their mass-produced counterparts. 

Like many automotive manufacturers, BMW and Mercedes have extensive racing backgrounds that yield the benefits of technological and performance advancements to their production models. However, both of these manufacturers also create a series of vehicles that share more with their race-driven brethren than that of their mass-produced counterparts. The vehicles not only boast more powerful engines, but also possess improved braking and suspension components to take full advantage of the horsepower bestowed upon them. 

Considered by some to be the world’s first motorcar race, the Paris–Rouen held in 1894 saw a single Benz in the field, which was driven by Émile Roger, who finished 14th.  During the 1914 French Grand Prix, the DMG Mercedes 35 HP racecars took all three podium spots. BMW’s first victory was on June 14, 1936 when Ernst Henne drove a BMW 328 at the Nürburgring at the vehicles debut.   

BMW Motorsport GmbH was created in Munich in 1972 with only a small staff whose goal was to monopolize the racing world. (Something I’ve always wondered about was the meaning of GmbH, as it is seen after the name of several German companies. Gesellschaft mit beschrankter Haftung means limited liability, which is similar to an LLC or Limited Liability Company.) 

Both BMW M-series (above) and Mercedes AMG series (right) vehicles boast engines that have more power than any other platform offered by either manufacturer. Above is a BMW M3 series V-8 engine.

Mercedes AMG C63 engine.

The M-series vehicles display the iconic blue/purple/red badge displayed by the original M1. Performance enhancements go beyond the engine compartment on a BMW M series, a total vehicle concept is used to ensure the entire vehicle is capable of handling the increased power.

In 1979, BMW Motorsport had its own new location within the BMW factory. The 3.0 CSL — dubbed “The Batmobile” because of its massive rear wing — was the first creation of this team. Porsche 911’s were prevailing over all racing classes that had regulations, requiring the vehicles on the track to be based off its production counterpart. A retired racecar driver, Jochen Neerpasch was the competitions manager of the motorsport division of BMW at the time and created the M1. This vehicle was the first of the BMW M series and was also the first vehicle to wear the iconic blue/purple/red M series badge. The M1 was created in 1972, with styling by Lamborghini, but not available for purchase until six years later. Regulation changes stated that a minimum number of the racing version of the M1 needed to be sold to the general public in order for it to be entered for competition. Unveiled at the 1978 Paris Motor Show, the BMW M1 became the first M-series vehicle also available to the general public. The M1 model E26 was produced from 1978- 1981; it boasted a 3.5L engine with over 273 horsepower. The total production was slightly more than 450 units. Then came the 535i, first the E12 Model from 1980-1984, then the E28 from 1985-1988.  Also the M635 CSi (E24) coupe was produced from 1984-1989; this was actually the first M6. Finally the well-known M-series vehicles started to be commonplace with the first M5 (E28 from 1984-1988; E34 from 1988-1995; E39 from 1998-2003; and the E60 and E61 from 2004-2010), the M3 (E30 from 1986-1991; E36 from 1992-1999; E46 from 2000-2006; and finally the E90, E92 and E93 from 2007-2013). The M6 (E63 and E64) was produced from 2005-2010. There was even a V-12 engine put in the M8 (E31), which was only produced in 1990. The X5 M (E70) and X6 M (E71) were added beginning in 2009. The first generation BMW M3, with its very stiff body, won more than 1,500 races in the European Touring Car Group A Championship Series. The second-generation M3 used in racing had regular BMW production components except for the tires, pistons and camshaft.

In 1980, BMW Motorsports started supplying turbocharged engines to the Brabham Formula 1 team. The 1982 Brabham BMW F1 vehicle was the first to use a digital engine management system; soon after, M-series vehicles adopted this technology. In fact, the BMW M3 and M5 engineers were responsible for creating the powertrain electronics for the 2000 BMW F1 race cars.

More recently, BMW has developed the F-series chassis with M-series vehicles. 

  • M2 (F87) 2015-Present
  • M3 (F80) 2014-Present
  • M4 (F82, F83) 2014-Present
  • M5 (F10) 2012-Present
  • M6 (F12, F13, & F06) 2013-Present
  • X5 M (F85) 2014-Present
  • X6 M (F86) 2014-Present

So what’s with the E and F coding of BMWs? These are chassis codes; the E stands for Entwicklung, which translates o Development. Since the E series were running out of room with the E90s platform, the next logical letter to go to was F.

How are the M series different from other BMWs?
BMW M-series vehicles start with a basic BMW platform. However that is where the similarities stop. More than 50 percent of the components that go into making an M-series vehicle are M specific. In fact, when it comes to an M3, more than 80 percent of the vehicle components are modified compared to a regular 3-series BMW.

Brakes, steering and suspension system components, including anti-roll bars, are changed and some redesigned completely. One of the main focal points is weight reduction, down to the last kilogram. Engine development works hand in hand with the design group to bring a vehicle that has both form and function. 

All the elements of the M series are tested in the ultimate proving grounds — the legendary Nürburgring, located in Nürburg, Rhineland-Palatinate, Germany, and constructed between 1925 and 1927. During research about the Nürburgring, one thing that could not be determined was how many actual turns there are; different sources have stated 73, 105, 154 and up to 170.

A picture of the distinctive fender design of an BMW M3. AMG name is actually the first letter of each of the two former Mercedes engineers who created the company (Aufrecht and Melcher), along with the birth place of Aufrecht, a town called Grossaspach.
Similar to BMW, Mercedes AMG creates vehicles that can also stop the massive horsepower their engine creates. Attention to design and detail is a trademark of Mercedes AMG GmbH.

While some manufacturers put a multitude of sensors on a vehicle to gain feedback with which to make adjustments, BMW relies solely on the seat-of-the-pants experience of their test engineers with which way to proceed.

The M headquarters are in Garching, Germany, with the actual design facilities located in Munich. The prototypes are built by hand. The engines are designed and tested in Preussentrasse, Munich. This facility has eight engine test benches, six stationary test benches and two engine dynos.

The M vehicles are produced on the same production line as the rest the series vehicles, the M3 at one facility and another for the M5 and M6. Interestingly, the carbon fiber roof is mated at yet another facility, which utilizes an advanced bonding process where variables such as temperature and humidity are closely controlled. This is crucial, as the roof is a major factor in the overall stiffness of the vehicle. 

The BMW X5 M and X6 M were created in 2010, however, they are not developed by the Motorsports division, but by BMW manufacturing themselves. The BMW M series has developed a performance version of almost all series offered except the 7 series. BMW has decided to leave the ultimate luxury platform to itself, however, they did partner with another German manufacturer to create the Alpina B7 with a Bi-Turbo V-8 engine.

Mercedes AMG GmbH
Mercedes AMG GmbH was founded in 1967 by two former engineers of the company — Hans Werner Aufrecht and Erhard Melcher — as a race engine development plant. Coincidentally, the first letters of their last names (Aufrecht and Melcher) along with the birthplace of Aufrecht, a town called Grossaspach or Großaspach create the companies’ name AMG. The two initially argued upon meeting at Mercedes because of a difference in temperament and different roles in the company. However, they eventually both realized they complimented each other and collaborated on an engine for the racing department. They were working on the vehicles at night, after work. Melcher covered Aufrecht’s apartment in drawings of direct injection, and the two actually produced the first direct injection — the 300SE —in Aufrecht’s basement.

The two set up shop in old mill in Bergstall, Germany. In 1971, they created the 300 SEL 6.8L AMG, which finished first at the 24-hour race of Spa. AMG started getting customer requests for changes, such as exterior modifications. Aufrecht said that their customers forced them to start a company. They obliged, and soon after the 300SL 6.3 became the flagship for them, not to mention a different breed of customer.

The shifting selector on a Mercedes AMG C63 with a Speedshift MCT (Multi Clutch Technology) 7-speed transmission. When in the Sport Plus and Manual modes, gear changes occur at a lightning fast 100ms between shifts. Mercedes AMG uses the “One Man One Engine” philosophy where a single person builds the engine from start to finish and their signature is placed on top of the plenum.
On a short test drive, the Reduced Engine Power light illuminated in the instrument cluster. Also during the test drive, an error message was shown in the central display area.

Some notable highlights of the company:

  • In 1978, AMG outgrew the factory at the old mill and moved about 12 employees to Affalterbach. 
  • Melcher developed a cylinder head touting four valves per cylinder in 1984. This is when AMG became an engine manufacturer.
  • In 1986, AMG put a 5-liter V-8 in a Mercedes E-Class coupe; this vehicle became known as the iconic “Hammer.”
  • In 1988, Mercedes contracted AMG for its motorsports division and its racing version of the C-Class claimed over 60 wins.
  • In 1998, AMG won every race in the FIA-GT series, in six of those racers they also claimed second place as well.
  • A cooperation agreement between AMG and Daimler-Benz AG was signed in 1990; however, the official incorporation of the two companies did not happen until 1999.
  • AMG opened a third plant in 1990 with its now 400 employees.
  • In 1993, the C36AMG is the first vehicle produced by both AMG and Mercedes; it would be available in the United States in 1995.  
  • In 2003, the AMG 5.5L Kompressor engine won the Engine of the Year* Award.
  • In 2005 the company introduced the iconic AMG 6.3L V-8.
  • In 2006, the AMG Performance Studio introduced two more series: The AMG Signature Series and the AMG Black Series.

In 1999, AMG became a majority-owned division of Mercedes-Benz. However, that is not to say that AMG has gotten away from its racing roots. In 2014, Mercedes-AMG won the Formula 1 Constructors Championship, powered by a 1.6L turbocharged V-6 with 701 points for the year.  To put the margin of victory into perspective, second place went to Red Bull/Renault with 436 points — not exactly a close one.

Today, there are more than 1,100 employees at the Mercedes-AMG GmbH plant in Affalterbach, 50 of which are engine builders. All AMG engines are built completely by one person, whose signature is placed on a nameplate on the top of the engine’s plenum. AMG Performance Studio also offers tours where visitors can watch the engines being assembled.

Different philosophies
While both BMW and Mercedes have their respective performance divisions, there are some very distinct differences between their philosophies. Mercedes produces AMG versions of several of their vehicles, including SUVs and luxury sedan platforms,

The Throttle-Valve Actuators are hidden under the air intake plenum. Each of the throttle bodies have individual air boots that need to loosened to remove the air plenum assembly.

whereas BMW had traditionally created an entire vehicle that they consider capable to handling the power. In other words, the overall structure of the entire vehicle needs to be adapted. For example, even the X5 M series had the suspension tuned with stiffer springs and bushings, modified wishbone suspension and a 10mm lower ride height. Also, until 2010, BMW M series only used naturally aspirated engines versus the supercharging used on the Mercedes AMG series. The BMW S65 V-8 and S85 V-10 engines used in the M series had an astonishing output of 100 horsepower per liter naturally aspirated.

Mercedes AMG has favored automatic transmissions for their vehicles, while the BMW M series has preferred manual or semiautomatic transmissions in theirs. The BMW X5 M and X6 M were the first M series to be made available with an automatic transmission to work with the all-wheel drive feature of the SUV. BMW’s seven-speed SMG (Semi-Manual Gearbox) Drivelogic transmission utilizes paddle shifters on the steering wheel — similar to Formula 1 racecars — to change gears. The transmission uses a double clutch system that allows gear changes without any interruption in power flow and the Launch Control feature helps to maximize straight-line acceleration from a standstill. The transmission offers five different electronic shift programs while in automatic and another six shift programs while in manual mode for a grand total of 11 different shifting strategies. The AMG Speedshift MCT (Multi Clutch Technology) is a seven-speed semi-automatic transmission, similar to the 7G Tronic used in a majority of the Mercedes C-Class vehicles, except that it does not use a torque convertor. To take off from a stop it uses a compact wet startup clutch. The Multi-Clutch Technology refers to the ability to have multiple clutches and bands for each gear to support the four different operating modes. Also in the Sport Plus and Manual modes, gear changes occur at a lightning fast 100ms between shifts. The transmission also boasts a Race Start Function that when enabled, allows full acceleration potential while maintaining traction and eliminating wheel spin.

M-series diesel
While Mercedes AMG GmbH has decided against performance diesel versions, diesels have benefitted from the BMW M series. In 2012, BMW introduced the M550dx and in 2014, the X5 M50d and X6 M50d. All of these M-series vehicles use the N57S Triple Turbo Diesel aluminum engine. It is an inline 6-cylinder common rail utilizing Bosch piezo-electric injectors outputting 381 horsepower and 740Nm of torque. The turbochargers consist of one large and two small units that are strategically utilized to deliver consistent power over a large RPM range. The smaller turbos are capable of spooling up faster to diminish any turbo-lag.

Things still go wrong with high-performance engines
Recently we had a customer bring a 2010 BMW M6 to us with a reduced power light on. This vehicle has a S85 V-10 engine for a power plant. The customer stated that when accelerating, a warning symbol came on the display similar to a check engine light, but only half shaded in.  The vehicle then went into a limp mode when this occurred; but after restarting, it operated normally again. A short test drive confirmed what the customer had described — the reduced power symbol appeared and the vehicle was brought inside for further diagnostics. The code retrieved was a 2B25 Throttle-Valve Monitoring Bank 1. Something unique about these engines it that they use one throttle valve actuator per bank on a setup of individual throttle bodies for each cylinder. See attached photos for a better understanding. These are definitely not easy to access, as an intake boot on each throttle body has to be removed to lift off the air plenum, so using a scan tool to perform as much fault elimination as possible before disassembly was key.  After running the self-test of the throttle actuators, Bank 1 showed a failure during testing.  After disassembly and checking connections at the throttle actuator, a new unit was installed and a learning calibration was performed to correct the concern.

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