The AMG SLS is one of those cars that tuners love to play with. With its naturally aspirated 6.2-liter V8 that produces 563 hp in stock form (583 Hp for the SLS GT), it's a very attractive basis to work on. German tuning company HMS took care of transforming the sexy coupé into a 771 Hp beast. And for the occasion, they also released a video of the dyno test to make us know how ferocious their SLS sounds. And what a sound! You'll love it.
You might also want to check World Motorsport's 850 Hp SLS which might not sound as good but is able to literally shoots flames at people.