Speaking of weight, the turbochargers and intercoolers add around 66 pounds in the engine compartment. However, since the SLS is a front-mid-engine design with its motor as far back in the chassis as possible, this has minimal effect on the car’s weight distribution.
The ECU undergoes a remap of the fuelling, spark and the variable valve timing curves, which all end up quite different to cope with the forced aspiration. The unit also features an integrated electronic boost control system.
The outputs are now 700 hp at 6600 rpm and 627 lb-ft at 4300 rpm compared to the standard 571 hp at 6800 rpm and 479 lb-ft at 4750 rpm. In terms of specific output, the numbers are 91.97 hp per liter for the factory engine, and 112.75 hp per liter for the 700 Biturbo.
Out of the box, the SLS AMG takes 3.8 seconds for the 0-62 mph sprint, and tops out at an electronically limited 197 mph. Any two-wheel-drive car will struggle to deploy such massive grunt off the line, so the 3.7-second 0-62 mph time recorded by the Brabus 700 Biturbo is not representative of how much quicker it is in real world conditions. Its 0.7-second faster 0-124 mph time of 10.2 seconds certainly is. If you can find a long enough stretch of autobahn, the extra torque and horsepower make full use of the car’s tall gearing and seven forward ratios to reach an unrestricted 213 mph. Late afternoon traffic conditions only allowed us to sneak up to around 180 mph a couple of times, but the obvious power still in hand at this speed made it clear that there was much more to come.
Torque is also what makes the Brabus 700 Biturbo a quite different animal in everyday driving. The standard SLS is not slow or lacking in grunt if you use the revs. But if you are in a high gear and want instant go, you’ll be met by smooth but less-than-sparkling acceleration until the rev counter needle passes the 3000-rpm mark. Matching the standard car’s peak torque at just 2000 rpm on its way to its much higher plateau, the Brabus 700 Biturbo is cooking with gas much earlier in the day. The extra thrust on tap means you don’t have to pay attention to the gear you’re in so much, and it would be realistic to say that you can drive everywhere at least one gear higher for a given situation.
On the autobahn, where you can sustain long blasts of full throttle acceleration, the difference is astonishing. Where the standard SLS moves rapidly away from most other cars you’re likely to encounter, the 700 Biturbo does so to an even greater extent, and with palpably less effort. It is the difference between having to use the throttle and just tickling it. Trekkies would describe it as the difference between impulse and warp engines. The greater torque at low rpm also means that in normal light throttle driving on the road, fuel consumption is no worse than standard, and could potentially be even better as you do not need to dig deep into the throttle.
The Brabus Ride Control system addresses the one area where the standard SLS chassis makes a compromise in the interest of its fine high-speed handling and grip. While it is widely accepted that the suspension is taut and compliant at high speed, the low speed secondary ride is a bit sudden on short, sharp bumps.