With this uprated motor as a starting point, Brabus changed the turbochargers and exhaust manifolds for bespoke units, which further improve airflow through the system.
"The factory manifold on all the Mercedes V12 engine variants is a big bottleneck," Gauffres explains. "Each cylinder bank has a single feeder pipe with one short exit pipe for each cylinder. The result of these unequal-length pipes is power-sapping backpressure and very high combustion chamber temperatures."
The Brabus manifold castings ensure that the exhaust gases from each cylinder stay separate for as long as possible. All 12 of these extractor pipes are of larger diameter than standard, and as close to equal length as possible.
In the factory setup, the turbochargers are exhaust gas driven only. The Brabus configuration uses exhaust pulses to augment the exhaust gases as well. Just using these special manifolds with the stock turbos already sees a greater than 50-hp gain, with a commensurate improvement in torque.
With the Brabus modified turbochargers, this extends to 100 hp and around 212 degrees (F) lower exhaust temperatures, the latter being good news for the long term durability of the engine. This is before the addition of the uprated intercooler system.
"The turbocharger housing and the turbine wheel are our own castings Gauffres says. "Only the center and the bearings are OEM parts. Over the years, we've accumulated a lot of knowledge on how much power you can get from the various OEM turbos and a given combination of OEM parts. It was design limitations that led us to take the very expensive step of designing and manufacturing our own parts.
"But we did not need to increase displacement with the SL65 Black Series V12 for a number of reasons," he continues. "First of all, the factory engine is already strengthened in this application, but more significantly, the car has much bigger intakes and more room in the engine bay than the E-Class, so its cooling potential is much better.
"Combine this with the same liquid-cooled, four water/air intercooler setup, and you gain sufficient intake temperature drop to allow the use of a slightly higher boost pressure than the 1.3 bar of the E V12 motor. This is a fixed peak setting with no overboost facility. We achieved the same power and torque as the 6.3-liter in the E V12 without increasing the standard 5,980cc displacement and 9.0:1 compression ratio." In this guise, the V12 biturbo is designated Brabus T65 RS rather than Brabus 6.3 R.
Thanks to its pre-engaged starter, the V12 fires up instantly with a sharp bark accentuated by the deletion of two of the exhaust silencers. It turns heads, but as the car was destined for Dubai, the louder soundtrack will not upset anyone. If anything, it will add to this monster SL's cache.
As even the facelifted SL has a lower bonnet line than the E-Class, the new intercooler setup is too tall for the central area. The solution was to cut a hole in the carbon-fiber factory hood, and add a bespoke power bulge. The bulge has been left in natural, unpainted carbon for maximum effect, and gives the car an even meaner and more purposeful visage should you dare to look it in the eye.
This car was originally white, but its owner wanted it matte black. A total respray would have been a nightmare, involving an expensive and time-consuming strip down. The increasingly popular self-adhesive film provided the answer. Whether in a gloss or flat finish, the film can provide impressive results, and the beauty is that if you tire of the color, you can change the color again or remove the film to revert to the original paintwork.