It's barely 5 a.m. and I'm doing my best to wipe the sleep from my eyes before climbing behind the wheel of a monstrous 900-horse twin-turbo SLS AMG. Photographer Robert Guio, Kerry Morse, and Editor Mike Febbo decided on a last-minute sunrise shoot opposed to the usual setting sun, which I tend to prefer. Both end up great, only I'm not such a morning person. At least not until I've had my cuppa caffeine. Truth be told, one press of the SLS' ignition button and you've got all the adrenaline boost you need.
Still dark, I do my best to quietly back out of the driveway and idle down the street simply out of respect for my sleeping neighbors. Only, there's no sneaking around in this car. Even at a mere idle, the deep rumbling of the engine is enough to wake the senses, and mine are now at full attention. In factory spec, the Mercedes-Benz SLS AMG is automotive performance engineering at its finest. Considered the spiritual successor to the legendary 300SL Gullwing and follow-up to the SLR McLaren supercar, the project was deemed so important that Mercedes-Benz boss Dr. Dieter Zetsche handed over complete design and build responsibilities to AMG. In doing so, aside from the homologated, barely-a-road-car CLK GTR, the SLS is the first production-run vehicle created entirely by AMG.
The SLS rolled off the factory floor in 2010 packing no less than 560 bhp from its handbuilt M159 6.2L V-8, at the time, the world's most powerful naturally aspirated production series engine ever produced. Coupled with its seven-speed dual-clutch gearbox, the rear-drive all-aluminum SLS proved it was everything AMG had set out to accomplish and then some—to build a car that pays homage to an icon while steamrolling its own course as a venerable supercar and instant classic unto itself.
While most would be quite content with the SLS' supercar performance, there are those who view the car as a canvas by which to explore even deeper into its bountiful possibilities.
Enter World Motorsports, a full-service tuning house for Mercedes-Benz, Lamborghini, Porsche, and McLaren. Based in Los Angeles, the company and its World Racing team have long since perfected the art of performance tuning, initially within the import car segment, where shop owner and race car driver Chris Rado and his World Racing team successfully built and campaigned championship-level NHRA Sport Compact Series and Time Attack race cars for nearly two decades.
Under the direction of Rado and business partner Craig Paisley, World Motorsports has evolved over the years into a highly respected tuning shop for European automobiles. Among its services, the shop houses a state-of-the-art Mustang wind-tunnel dyno facility, which matches air speed to vehicle speed, allowing the type of dynamic testing only the manufacturers would otherwise possess. It's the only wind-tunnel dyno of its kind in the country, according to Paisley.
The SLS was purchased new as a test bed to design and build a turbo package for the car, as well as upgraded turbo packages for other M-B models. Literally years in the making, the project exhausted thousands of hours in research and development before finally settling on the current setup. "We could have easily bolted up a couple turbos, ran tons of boost, made uncanny amounts of power on 100-plus octane, and just called it a day, but that was never our objective," Paisley said. "We had very specific criteria. In addition to providing huge horsepower gains, the car needed to maintain all of its luxury and creature comforts, which also meant it needed to hit our target numbers and run beautifully on 91 pumped gas."
The result of their efforts paid off in the form of the SLS TT900, which we were lucky enough to experience firsthand. With very light traffic heading out to the shoot, I was finally comfortable enough to lean on the throttle, but forget about flat-out mashing the pedal. While the TT900 package is remarkably refined offering restrained composure around town, it doesn't take much to be reminded that there's a caged beast under the hood, and it's just waiting to break out. A prod of the pedal is like poking a bear, and you better be prepared to run.
Just a stab and the mighty V-8 lets out a ferocious roar, spinning the wheels while thrusting forward with neck-breaking acceleration. This is a car that will quickly make you respect its awesome power and plenty of open-road is requisite. Keep it buried on a long enough stretch and I have no reason to question a top speed far exceeding the 200-mph SLS AMG Black Series. The company also claims the car is good for a 0-60-mph sprint at just a few clicks over 3 seconds, which I also have no cause to doubt.
All of this incredible power and, surprisingly, its custom Turbonetics T3 61mm twin-turbos use just 6 pounds of boost. The engine also maintains its factory compression of 11.3:1. The setup provides alarming amounts of low-end pavement-pounding torque and brute power that builds with intensity all the way up through the high-revving rpm band. Dyno figures boast an impressive 900 hp at the crank—on 91 octane to boot.
In addition to the custom front-mount intercooler, the turbos are neatly tucked away underneath and mated to custom-fabricated World Motorsports headers and exhaust, leaving nothing but clean lines up top showcasing hefty parallel intakes with optimized Rado filters and housing. With more than ample room, everything is packaged beautifully, maintaining a factory clean appearance.
The remapping of the Bosch-sourced factory ECU includes recalibrated fuel, ignition, and camshaft-phasing curves. Custom programming of the gearbox was also in order, as well as a reworked clutch setup. Paisley was quick to point out that a great majority of the development time was spent fine-tuning the engine management. "Forget about all the time spent on engineering and development of the package hardware and installation; it dwarfed in comparison to the man-hours spent dialing in the engine management, but we weren't stopping for anything less than perfection." In our estimation, time well spent, as the additional horsepower couldn't be more seamlessly matched.
To keep the car firmly planted at speed as well as in the corners, the suspension was tightened up with the use of KW coilovers with adjustable sway bar endlinks. An aggressive carbon-fiber body kit rounds out the aerodynamics, including a World Motorsports front splitter, side skirts, and rear diffuser. Matching carbon air inlet vanes were also added. While not on the car during our drive, for additional downforce, World Motorsports offers a towering GT3-style carbon-fiber wing as an alternative to the factory spoiler.
Running through the canyons, the SLS takes firm command of the road, muscling through each turn with a certain unyielding aggression and authority. A set of lightweight HRE S107 forged wheels equipped with sticky Continental ContiSportContact 285/30/ZR20 and 325/30/ZR20 tires supplies the much-needed grip while also being civilized enough for daily driving duties.
Winding through the tighter sections, the turbos prove a perfect match for the 6.3L, spooling quickly with zero noticeable lag and providing instant bottom-end grunt with overall grizzly brute strength. In and out of the throttle, the engine roars then barks, snarls and crackles, echoing loudly off the canyon walls. There's truly nothing like the exhaust note of a twin-turbo-charged V-8.
The package will set you back around 45 grand installed. Money no issue? The company also offers an even bigger beast with its monstrous TT1100 package, which includes completely reworked engine internals and gearbox.
Pushing the performance limits of a world-renowned supercar such as the SLS is no easy feat. Doing so while also maintaining Mercedes-Benz AMG levels of driveability, luxury, and refinement is harder still. And yet this is what the team at World Motorsports has achieved quite handedly. We think Dr. Zetsche would be proud.