In stock form, the 2013–14 Mercedes-Benz SLS AMG Black Series is already one of the wildest front-engine supercars ever made. Inspired by AMG’s GT3 race car, the Black Series came with a full carbon fiber package, including the hood and torque tube, which are both made of aluminum on lesser gullwings. AMG also lowered the seven-speed DSG transmission, shortened the rear-axle ratio, added six-piston carbon ceramic brakes and a titanium catback exhaust, and stiffened up the active suspension by quite some margin, going for wider tracks and bigger wheels as well.
The hand-built 6.2-liter naturally-aspirated V-8 also gained a handful of racing parts in order to have an 8000-rpm redline and 622 horsepower, with torque being slightly decreased to 468 lb-ft. The overall result of all this factory tuning was an SLS that was not only 154 pounds lighter but also as wild to drive as any street car with a Mercedes badge could get.
Keeping that in mind, what do you do if you crave even more power, but don’t want to mess with AMG’s jewel of a V-8? You call Michael Weiss, or one of his partners at Weistec, like IndyCar driver Graham Rahal, owner of this 825-hp SLS Black that a certain comedian enjoyed so much on Jay Leno’s Garage.
While Rahal’s open-wheeler has a maximum of 750 horsepower, and maybe another 60 for overtaking, his street car produces at least 825 hp at the flywheel, along with torque in the 600s. That’s thanks to Weistec’s $16,000 3.0-liter supercharger upgrade, which bolts onto AMG’s already overbuilt, rock-solid 6.2-liter, along with an ECU tune and a few heavy-duty belt upgrades made here and there. And with Weistec designing and building all its parts in-house, including the cast aluminum intakes and the free-flow exhausts, the Weistec SLS 825 looks like something that could have come straight from Affalterbach, even if the SLS AMGs were actually built in Sindelfingen.