With little in the way of external revisions, German tuning company Posaidon has released their take on Mercedes-AMG's S 63 AMG S Cabriolet, calling it the S 63 RS850+. While fellow European modding studios Renntech and ABT spend plenty of time upgrading suspension geometries as well as exterior details, interior luxury, and aerodynamic bits, Posaidon seems committed to a level of exterior understatement that makes their products some of the best sleepers on the market today.
As the S 63 RS850+'s name suggests, the hand-built, twin-turbocharged V8 under its hood now churns out around 850 horses at the wheels - or somewhere just north of 1,000 hp and 1,030 lb-ft at the crank. (For context, a stock S 63 AMG S leaves the factory producing 577 horsepower and 664 lb-ft of torque.)
While a new set of wheels do fit into the mix, the luxury convertible's exterior doesn't look radically different from a stock car straight off the dealer floor, especially given the level of individualization Mercedes offers to buyers of their (starting price) $168,695 super coupe. With a long options checklist thrown into the mix, that price tag can easily climb north of $200,000.
Mercedes-AMG's hand-built V8 receives plenty of custom work from Posaidon to help beef up its internals in support of such insane power. The engine is first stroked to 6.3 liters of displacement, with steel cylinder bushings, an updated main bearing line, and tweaked compression ratios as well as reinforced valve springs. The two turbochargers receive modifications to aid boost buildup alongside a custom air kit including a high flow air filter. A beefed up radiator, stronger set of differentials, and the seven-speed automatic transmission's internals also receive attention.
Posaidon claims their work results in a 2.9 second sprint to 60 miles per hour, on the way to a top speed of 218 mph. Those stats are greatly improved over the world's previous (Brabus-tuned) fastest S 63 AMG which produced 838 horsepower and 848 lb-ft of torque and could hit 60 mph in 3.9 seconds. With power figures this impressive, it seems Posaidon may be taking a route more akin to the insane geniuses across the Atlantic Ocean at Hennessey Performance.