Yes, it will be more powerful than the GT R.
We though it was a bit strange when AMG revealed the hardcore, track-ready version of the GT and it did not use the Black Series moniker. The Black Series badge is typically reserved for the most rare and hardcore AMG models, but Mercedes instead decided to confuse people with a name Nissan has used for decades. Still, we heard rumors the GT R wouldn't end up being the most hardcore GT and a Black Series version was on the way. In an interview with CarAdvice, AMG finally confirmed it.
Speaking at the 2018 Geneva Motor Show, AMG boss Tobias Moers spilled the beans on this highly anticipated model. "There is a GT variant still left… We are on the journey, we started the journey for Black Series," Moers said. He went on to say 2020 would be a very "interesting year" for Mercedes, indicating this is when we would finally get to see the GT Black Series. The most aggressive version of the car will act as the final model in this generation. Details on the Black Series are minimal, but we can expect it to be the lightest, most powerful model in the GT range.
The 4.0-liter twin-turbo V8 produces 577 horsepower in the GT R, but we've seen this engine producing as much 630 hp in the recently announced AMG GT four-door. The GT Black Series may not have quite as much power because it will be RWD, while the four-door is AWD. Still, the GT Black Series has the potential to be one of the best AMG cars of all time and we can't wait to finally see it. The car will likely cost 10-15% more than the $157,000 GT R, but could see markups due to a low-volume production run.