The Brabus 850 6.0 Biturbo iBusiness and I first met back in March 2014 at the Geneva Motor Show. The latest in a long line of extremely well-appointed Brabus S-Class models, this über-sedan offers supreme speed, comfort and connectivity for the tycoon on the move. However, with the Brabus stand offering plenty of captivating machinery and dozens of new car unveilings going on elsewhere at the show, this was not the time or place to get to grips with the world's fastest business tool on wheels.
A few weeks later, I visit Brabus HQ in Bottrop, Germany, on a pilgrimage to familiarize myself with the 850 6.0 Biturbo iBusiness, minus the distractions. And because of the car's doubled-edged mission statement to excel in both kinds of hustle, I'll be conducting this test from the back seat as well as behind the wheel.
Straight from the factory, the current W222 S-Class is an imperious conveyance. Its visual presence is an important aspect for owners, especially in places like China and the Middle East where social status—or at least its perception—is everything. With distinctive AMG styling and larger alloy wheels, the S63 AMG carries even more cachet. However, when the car reaches Bottrop, the Affalterbach tailoring is morphed into something altogether different. Like swapping Boss for Armani. Neither is better than the other; it's merely a matter of taste.
Brabus styling changes are built on the AMG aero kit, adding carbon-fiber components to the front bumper, with more aggressive airscoops around the big side intakes. Carbon fiber is also used for those inserts just behind the front wheels.
The chromed radiator grille is shot-blasted and repainted in matte titanium gray to tone down the imposing (and rather bling) nose of the standard car. This de-chroming process is applied to all the brightwork. The window frames and rear trim strip above the license plate also receive the titanium treatment.
New side skirts of OE-quality polyurethane reaction injection molding (PU-RIM) replace the AMG originals, containing LED lights for night illumination that can help prevent exiting occupants from stepping into a puddle or pothole or worse.
At the rear, a new carbon-fiber insert incorporates a diffuser flanked by cutouts for two distinctive exhaust outlet shrouds that have been CNC-machined from billet aluminum. A PU-RIM trunk lid spoiler adds the finishing touch.
Brabus offers a choice of 21-inch or 22-inch lightweight forged alloy wheels for the S-Class. At the Geneva Show, one of these options is fitted to each side. So the driver side features the 9.0 and 10.5 by 21-inch Brabus Monoblock R in liquid titanium smoked finish, with 255/35 ZR21 and 295/30 ZR21 Continental Sport Contact 5P tires, going from front to rear. Meanwhile, the other side wears 9.0 and 10.0 by 22-inch Monoblock G rims with 255/30 ZR22 and 295/25 ZR22 Pirelli PZero Nero rubber.
Behind the spokes of either wheel design is the Brabus big front brake kit. Clamped by huge six-piston calipers, the 15-inch (380mm) vented discs are made by Brembo from a new carbon-ceramic material that is claimed to significantly improve thermal transfer for optimum braking performance under tough conditions. The rear setup is stock S63 AMG.
A lowering module for the Airmatic suspension drops ride height by 0.6 of an inch without any negative impact on comfort. In combination with the aero kit and the bigger wheels and tires, the car looks even more purposeful.
Converting the 5.5-liter AMG M157 biturbo V8 to achieve 850 hp is a work of engineering art. While it is possible to extract 800 hp from this engine with no change in displacement, the level of power and torque targeted by Brabus required more capacity as well as strengthened internals.
Out of the box, the M157 motor deploys a bore and stroke of 3.86 x 3.56 inches. The Brabus conversion uses a custom-made billet steel crankshaft, machined billet connecting rods and forged Mahle Motorsport pistons to take the swept capacity to 5912 cc with a bore and stroke of 3.9 x 3.78 inches. The company's deputy development chief, Jorn Gander, explains that the new pistons have to be shorter to stay close to the stock compression ratio of 10:1, although the shorter connecting rods raise the thrust angle.
"We increase boost pressure to between 1.1 bar (16 psi) and 1.2 bar (17.4 psi) depending on engine speed, and this peaks at 1.3 bar (18.8 psi) on overboost," Gander says. "The greater combustion pressures and temperatures require a special head gasket material. This comprises three bonded metal layers to create a gasket that reliably meets those physical demands."
In the old days, Brabus would have swapped the camshafts for ones with higher lift and longer duration, optimizing power and torque. However, while the bottom end of the motor has seen radical modifications, the top end is stock except for gas-flowed cylinder heads. The reason is simple. All fine-tuning these days is done with variable valve timing controlled by ECU mapping, so what used to require new hardware has now become an exercise in software tweaking.
On the subject of ECU remapping: fueling, ignition, valve timing and boost pressure are all recalibrated for the larger-capacity motor, deeper-breathing intake, larger turbochargers and the lower back pressure of the bespoke exhaust system.
Revised electronics also allow the motor to run closer to detonation for more power. This is quite safe. The factory knock sensors are precision-tuned to retard the ignition well before the danger point, protecting the motor in case of poor fuel quality, especially in high ambient temperatures.
To achieve maximum-intake airflow, Brabus employs a setup similar to its first E V12 800. "We designed a carbon-fiber ram air collector system that sits between the grille and hood and feeds air to a custom high-flow filter box for each cylinder bank with 45 percent more surface area than stock," Gander says. "When the hood is closed, these boxes are sealed and so [they] maximize air pressure."
Carbon-fiber pipes feeding air to the turbochargers are also larger in diameter and, like the intake pipes, are covered in a gold heat-reflecting material. "We did a lot of testing to optimize the intake and charge-air pipe diameters," Gander says. "With the higher airflow and bigger turbos, we had significant loss under-pressure using the standard pipework, so we had to go larger to reduce power loss. It is always a balancing act. If you go too big, power starts to fall off again."
The stock housing of each turbocharger unit is internally machined to take a larger compressor wheel, then mounted on a custom exhaust manifold with larger-diameter pipes made as close to equal length as possible within the confined space of the engine bay.
Unlike some tuners whose conversions are only designed to meet current EU emissions laws, Brabus always aims to fulfill the same emissions standards as the factory product. The 850 engine is therefore homologated to EU6 standards. To do this requires the latest sport catalytic converter technology, and Brabus worked with an OE supplier to obtain a 400-cell metal unit with double the reactive surface area, yet with no more backpressure than the 200-cell units used before. At 3 inches in diameter, the downpipes are bigger than stock and each cylinder bank sends its gases to the rear through a pipe 0.04 of an inch larger, with middle and rear silencer boxes along the way.
All this results in a huge jump in output from the stock 585 hp at 5800 rpm and 663 lb-ft of torque between 2250 and 3750 rpm, to 850 hp at 5400 rpm with 847 lb-ft of torque from 2500 to 4500 rpm. The dyno actually saw 1069 lb-ft of torque, but this has been dialed back electronically to protect the drivetrain.
Even so, the seven-ratio Speedshift MCT transmission is beefed up to ensure long-term reliability, and Brabus added a limited-slip differential with 40 percent locking. This partnership dispenses torque-to-tarmac efficiently enough to ensure a sprint from standstill to 62 mph in just 3.5 seconds. Top speed is limited electronically to 217 mph, which is an all-time record for this class of car.
From the well-upholstered driver seat, there's an immediate feeling of immense power and torque. The standard S63 AMG is a snarling beast in a smart suit. With its exhaust valves open, the 850 iBusiness does nothing to disguise an even more aggressive nature. Activating those valves (at the touch of a button) will dampen things down a bit, but there's no hiding the ferocity under the hood that seems to be biding its time until the driver opens the throttle again.
Step on the gas and the car lunges for the horizon with a fervor that made me thank Mercedes-Benz for its excellent self-leveling Airmatic suspension. The last time I experienced anything similar, there was a big Brabus twin-turbo V12 involved. Now this smaller and lighter twin-turbo V8 can convincingly out-punch its big brother. That's progress.
If the exterior looks imposing, a lavishly appointed, handcrafted cabin exudes an expert wielding of color and texture that complements countless luxurious details. The finest soft hides in tobacco and snow-white leather, with matching tobacco headlining in Alcantara, make for a strong contrast with the metallic black paintwork. The almost-black carbon-fiber inlays have a hint of dark brown, harmonizing nicely with the leather.
To sit in the rear compartment is to experience one of the two seats that can be either mission control for business deals or an entertainment center on the move. All major functions here are controlled by the iPad mini or iPod touch. The holder for the former is in the drop-down central armrest; a cradle in the center console accommodates the latter.
There are three video screens in the back. The two behind the front seats are factory units. Brabus supplements these with a 15.6-inch monitor that descends from a specially made compartment in the headlining. This is part of the iBusiness package, whose core is a Mac mini stored in a motorized drawer built into the under-shelf area of the trunk. Audio from the Mac mini and Apple TV is routed to the excellent Burmester sound system.
A Brabus remote app activates the ceiling-mounted monitor, switches the Mac mini on and off, controls the video source (Apple TV or DVD) and the opening and closing of the drawer in the trunk. An onboard WLAN router sets up a hotspot, and all Internet-connected devices are run off this.
Not long ago, in-vehicle office facilities tended to be clunky, with a distinct lack of integration between software and hardware. But now, thanks to 3G and 4G cell phone technology, along with the superior connectivity of Apple's ecosystem, we can reach out and touch the world more easily while on the move.
The Brabus 850 6.0 Biturbo iBusiness is not the only vehicle in the world to be equipped so comprehensively with business and entertainment tools, but you can bet it will be the fastest of its kind for quite some time to come.