'Power, torque and sound’. That’s how Carlsson describes its three biggest priorities in developing its new CK63 RSR (read: ‘very fast CLS’). Not, you’ll note, ‘sparkly wheels’, ‘glitzy decals’, or even ‘spangly bodykits’ – though there are a few very subtle changes to the CK63 RSR’s cosmetics, more of which anon.
The main priority, though has been more power. Lots more power. Carlsson’s renowned for its founder, Rolf Hartge’s expertise in extracting vast amounts of power from production Merc engines. In this instance, he and his team have taken the CLS63 AMG’s 5.5-litre twin-turbo V8 – already no slouch – and added their own software to take it to 700hp. Peak torque has been limited to 737lbft, meanwhile, to make sure the gearbox and the rest of the drivetrain doesn’t have a small fit. Carlsson has also had to add a higher-flowing intercooler system and a selection of water and oil coolers, as well as that uprated exhaust.
And of course, there are those external upgrades. Thankfully, these have been kept as unobtrusive as possible, though there’s one notable change from the lower spec CK63 RS in the form of an electronic rear spoiler that rises at 62mph. Carlsson says that this, in combination with the new rear diffuser, has been wind tunnel tested to help reduce lift at the rear. Inside, much as you’d expect, there are swathes of Alcantara, wood and carbon fibre, as well as the hides of several herds of Friesians.
The CK63 RSR will be unveiled officially at Geneva, with order-taking to commence shortly thereafter.