Here's what you need, warrantied and semi-official, shame its a lease car :)

08.05.2018 - Performance upgrade to 588 kW / 800 hp

The latest Mercedes E 63 and S 63 models are powered by a twin-turbo V8 with a displacement of 3,982 cc. This engine offers great performance reserves, which the BRABUS power unit engineers unleash with their latest performance upgrade. To this end, they used their tremendous expertise from more than 40 years of tuning to develop the 800 performance kit. This conversion comprises two BRABUS high-performance turbochargers with a larger compressor unit and a modified core assembly with reinforced axial bearings. They produce a maximum boost pressure of 1.6 bar.

The engine tuning also comprises a plug-and-play BRABUS PowerXtra module, which is connected to the vehicleÂ’s electronic engine control unit and provides the engine with new mapping for injection and ignition. In addition, this control module also modifies the electronic boost pressure control. This engine conversion produces an extra 138.4 kW / 188 hp (186 bhp) of power and 100 Nm (74 lb-ft) more torque. BRABUS recommends hi-tech lubricants from technology partner MOTUL.

With an output of 588 kW / 800 hp (789 bhp) at 6,700 rpm and a peak torque of 1,000 Nm at 3,600 rpm, the BRABUS 800 accelerates from rest to 100 km/h (62 mph) in just 3,0 seconds for the E 63 and 3.1 seconds for the S 63.