RennTech Is Turning a Classic Mercedes SEC Into a 660-HP V12 Sledgehammer

Key Points

• RennTech is creating a Mercedes SEC restomod with a 7.5-liter version of the legendary M120 V12.
• Engine produces 660 HP and 650 lb-ft torque.
  Only 12 units will be made, starting in 2027.

Mercedes’ legendary M120 V12 engine is no stranger to big displacements. Found in top-end versions of the S-Class and SL throughout the ’90s, and getting a second life in the Pagani Zonda, the smallest iteration of the engine was still 6.0 liters in size, and it went as big as 7.3 liters in the ultra-rare SL 73 AMG.

Now, though, esteemed Florida-based Mercedes tuner RennTech is preparing to push the powerplant even further with a mighty 7.5-liter version, set to arrive in 2027 in the SEC V12 Widebody Sledgehammer, a restomod based on the C126 coupe version of the ’80s flagship W126 sedan.

A Big Engine Made Bigger

RennTech’s 7.5-liter take on the M120 engine will take what was already one of the largest post-war V12 engines ever fitted to a production car and make it even bigger. Built in-house, the tuner claims it’ll churn out 660 HP and 650 lb ft of torque – figures only bested among versions of the engine by the various uncorked track-only editions of the Zonda.

Although designed first and foremost for refinement and smoothness, various viral videos have shown that, with a trick exhaust, the M120 also is more than capable of producing a serious F1-like V12 wail. The Widebody Sledgehammer should tick that box, too, as RennTech says its 7.5-liter motor will get a set of equal-length headers for ‘a signature V12 sound’.

RennTech’s only released a few renderings of the V12 Widebody Sledgehammer so far, but it’s clearly a tribute to what many would view as AMG’s golden era, when it was still a separate entity to the Mercedes mothership, taking the company’s cars and turning them into ultra-exclusive statements of excess.

As the name suggests, it’ll get a seriously pumped-up body compared to the C126 donor car, with a custom widebody kit, aero addenda including functional ducting and diffuser, and lightweight forged wheels.

The ‘Sledgehammer’ name, meanwhile, is a nod to one of the most famous AMG products of all, the ‘Hammer’ – a 6.0-litre V8 version of the smaller W124 coupe.

An Exclusive Prospect

That’s about all the info RennTech’s released on the Sledgehammer for now, besides the fact that not many people will get to experience it – the tuner says it’ll build a limited run of just 12 cars. The first will arrive in 2027, by which point we should have some more concrete info on the car.