A fast car careens down the highway, and it’s immediately noticeable. Supercars probably don’t need more attention than they already get, but these tuning companies thought otherwise. Each takes an already fast car and makes it even faster, even after in-house tuning companies have taken a shot. It might be blasphemy to take a Carrera GT, for example, and give it some more juice, but the heart wants what it wants. These are just five already fast cars transformed by tuning companies.

Mansory’s Audi RS7 nips at the heels of Lamborghinis

Mansory Corporation got its start in the late 1980s with Rolls Royce, Ferrari, Bentley, and Aston Martin. Today it modifies cars from almost every European brand into certifiable death sleds. The Audi RS7 began life as an expensive luxury sedan, with a modest 591 horsepower from its 4.0-liter turbocharged V8. Mansory took it several steps further and gave the RS7 bigger turbos and a high-performance exhaust system, resulting in 780 horsepower. This monstrosity only takes three seconds to reach 60 mph.

Tuning company RTR ‘roided-up the Ford Mustang

One man’s idea bred the RTR tuning company in 2007. Vaughn Gittin Jr. had a vision for the outdated Mustangs of the time and sought to build his own tuning company to bring the car into the 21st century. For $21,000, you can buy the RTR Spec 3 package for the 2021 Mustang GT. It includes a Ford Performance supercharger kit that helps the little Coyote engine produce 750 horsepower and a laundry list of external changes. New adjustable suspension and big-boy tires complete the package.

Gemballa revitalized the Porsche Carrera GT

Tuning icon Gemballa got its start in 1981 and has since dabbled with Mercedes-Benz, BMW, and Ferrari cars. Today we’re looking at the Porsche Carrera GT. Unfortunately, the Carrera GT’s reputation is synonymous with fire and Paul Walker’s unfortunate death. Before that event, the Carrera GT was known as a 605-hp supercar with a 5.7-liter V10 and a big rear wing. Gemballa gave the Carrera GT 670 horsepower thanks to a new exhaust, intake system, and a remapped ECU. Gemballa’s Carrera GT, or “Mirage GT”, tops out at 208 mph.

McLaren MP4-12C further refined by Fab Design AG tuning company

Fab Design AG came about in 1997 and currently operates in Switzerland. It specializes primarily in Mercedes-Benz (including Maybach) and McLaren cars, which brings us to the MP4-12C. The MP4-12C was McLaren’s second-ever road car, following the highly-regarded F1 supercar. In factory spec, it got 616 horsepower from its twin-turbocharged 3.8-liter V8. Rather than go the insane all-horsepower route, Fab Design took gentle care of the McLaren and gave it a modest 32-hp increase. It also got a new aero kit, bigger air intakes, and massive rear tires. 

Tuning company Underground Racing’s Dodge Viper: insanity begets insanity

The Dodge Viper is already one of the most ridiculous cars ever produced. From its inaugural 1994 model year, it used an 8.0-liter V10 with 400 horsepower and only got more power with each successive generation. It finally got traction control by 2013, which is worrisome because this particular customer’s Underground Racing-tuned Viper is from 2006. With twin turbos and a 530-ci engine, dyno charts prove an excessive 1757 horsepower at the wheels, topping out at 160 mph.

At this point, it’s safe to say supercars aren’t safe from wide-eyed tuners and third-party engineers. Each one might as well roll off the assembly line and into the garage, but we aren’t complaining. Sometimes car manufacturers don’t squeeze every last drop of power from production cars, and that’s why these tuning companies exist.