Given that the base vehicles used in Brabus' two prior "world's fastest" efforts are all Mercedes, and each uses the V12 Brabus motor, much of the knowledge required for building this supercar had already been acquired prior to commencement of the project.
The Brabus 800E V12 cabriolet begins life as a brand new Mercedes E-Class Cabriolet. The biggest single change is a heart transplant with the donor heart (a three-valve Mercedes S 600 V12) also getting a significant makeover before being surgically implanted. The end result is a 6.3 liter, Biturbo V12 producing 788 bhp (588 kW) @ 5,500 rpm and a peak torque of 1,420 Nm (1,047 lb-ft) which is limited electronically to 1,100 Nm (811 lb-ft).
The BRABUS 800 V12 is fitted with a high-performance limited-slip differential with a locking rate of 40 percent, and despite the relatively heavy weight of the Mercedes E Class, can accelerate from standstill to 100 km/h (62 mph) in just 3.7 seconds.
That's supercar class sprint acceleration, but the Brabus 800 keeps accelerating at this outrageous rate, passing 200 km/h (124 mph) in under ten seconds (actually 9.9 seconds) and 300-km/h (186-mph) in 23.9 seconds. Depending on the final-drive ratio, the BRABUS 800 E V12 Cabriolet tops out at 370 km/h (231 mph).,
The engine used in the vehicle is the most powerful engine built by Brabus - a stroked and bored V12 three-valve Mercedes S 600 unit, which expands capacity from the standard 5.5 liters, to the Brabus engine's 6.3 liters. There are many aspects to the re-engineering of the motor - different camshafts, flowed heads, a new intake manifold, new exhaust manifolds with integrated very large turbos, four water-to-air intercoolers, a beefed up five-speed automatic transmission, an entirely new high-flow, stainless-steel exhaust system, and newly programmed mapping for the electronic engine management system.
All the aerodynamic-enhancement components were refined in the wind tunnel, and all are made from carbon fiber. The front apron is designed to both reduce lift on the front axle and guide cooling air to the radiators and front brakes. Air outlets in the sides route the hot air away from the heat exchangers as quickly as possible.
For further improved directional stability at extremely high speeds and to further increase cornering speeds, BRABUS widens the body of the E-Class Cabriolet. Newly designed front sport fenders widen the track and allow the installation of ultra-wide 9.5Jx19 wheels mounted with size 265/30 ZR 19 tires.
Professional engineering work was also invested into every detail of the suspension: special suspension components were custom-designed for the front and rear axle of the BRABUS E V12 Cabriolet. They provide a much wider range of individual suspension settings. These components are joined by a BRABUS coil-over suspension calibrated to the higher engine weight. The suspension was developed together with Bilstein and features ten selectable settings for bound and rebound front and back. The ride height can also be adjusted by up to 35 millimeter.
The BRABUS high-performance. It features 380 x 37 millimeter (15.0 x 1.45 in.), vented and grooved steel brake discs and 12-piston aluminum fixed calipers on the front axle. The rear stops on 360 x 28 millimeter (14.2 x 1.1 in.) discs with 6-piston aluminum fixed calipers.
The cockpit is clad in a perfectly finished combination of lipstick-red and black leather. The ergonomically shaped BRABUS steering wheel and inlays made from genuine carbon fiber on dashboard, center console and side trim add sporty highlights. The speedometer with 400-km/h (250-mph) dial bears witness to the unique performance potential of the open- top four-seater car even while it is standing still.
When the engine is in place, and the hundreds of other modifications to the vehicle have been completed, it has a top speed of 370 km/h (231 mph) and a price tag of EUR 478,000 (US$682,000).