Brabus SL55 K8
For the vast majority of people, the 476-bhp SL55 AMG is fast enough. After all, any car capable of accelerating from 0 to 100km in under 5.0 sec. and on to over 200 mph once you remove the limiter, should be as fast an anyone would want to go, even on the autobahn.
Apparently not, for since this fastest-ever production Mercedes-Benz was announced, some of Brabus' best customers have been on the phone asking when the power upgrade for the SL55 AMG will be ready.
The result is the Brabus K8, which made its first public showing at Geneva in March. I was the first to drive the car after its return to Germany and came away stunned by the depth and breadth of its performance.
Think about it. The standard SL55 AMG packs a supercharged 476 bhp and 516 lb-ft (700Nm) of torque under its sleek bonnet, but the Brabus K8 version raises the stakes to 530 bhp with 572 lb-ft of torque at 3470 rpm.
The K8 blasts to 60 mph in 4.4 sec., but right now its top speed is limited to 188 mph because of tire speed ratings. On special 18-in. tires the car should reach 206 mph, but such rubber is not yet widely available for a car of this weight.
The 188 mph I achieved came easily, though, as I swept up the autobahn A31 from Bottrop, heading for the Dutch border. Traffic was light, and within minutes I found a clear stretch of road where I could open the car up.
As fast as the stock SL55 AMG is, the extra urge of the K8 conversion is simply astounding. Even in fourth and fifth gears, the speedometer needle climbs round the scale almost as fast as its counterpart on the tachometer. The other eyeraiser was that the AMG Speedshift even kicked down a gear when I accelerated from an indicated 155 mph, bringing the engine back into the meaty bit of the torque curve for maximum possible acceleration.
At close to 200 mph, things happen both very fast and very slowly at the same time. If you relax and look really far ahead, the horizon appears to be reeling in and yet it stays put. Your peripheral vision tells your brain that the world is whizzing past at an immense rate, but that horizon never actually gets any closer. It is a very strange feeling, quite different from the one you get in an aircraft where there is no long strip of tarmac connecting your relative position with the horizon. It is almost like being on the fabled event horizon of a black hole.
The punch is the back is not so much explosive as compulsive. The more you feel it, the more you have to have it. It gives you real seven league boots in the way that a powerful jet plane does. There is simply so much surplus thrust there for the asking, you are almost surprised that a mere road car can contain it safely. It shows just how good the basic SL chassis is with its clever ABC suspension.
Using the AMG 476-bhp supercharged motor as a base, Brabus set out with a 10%-plus gain in power and torque in mind to make the K8 conversion worthwhile. "We use new ventilated pulleys on every single component in the system to make sure all the relative gearing is correct and the belt is kept cool, as belt life is governed largely by heat stress," he explained. The cooling capacity of the engine is also increased by 50 percent to keep charge air temperatures low and the engine healthy.
"At the factory 0.8 bar boost, the IHI supercharger consumes 91 bhp at peak revs," Jorn continued. "We run 1.1 bar boost on the K8 conversion, and now the system consumes 106 bhp but gives back even more. We claim 530 bhp, but as you can see from the dyno chart, we got 548 bhp on this particular car. Bear in mind that manufacturers have a 5% tolerance on output, and that falls broadly into this area."