Renntech has built a special one-of-one W140-chassis Mercedes-Benz S-Class to show the world what it’s capable of. Under the hood of this already classic 1992 Mercedes 600 SEL is the largest displacement M120 V12 ever built at 7.6-liters pumping out 615 hp (458 kW) to the rear wheels only. Here’s a detailed look at one of the slickest pieces of rolling advertising we’ve seen this year.
For the unaware, Renntech is a performance engineering firm founded back in 1989. Since then, it’s created some of the most overbuilt modified Mercedes models ever. At its helm is Hartmut Feyhl, a man with 12 years of job experience at AMG before spending time as the North American division’s technical director. He knows how to make a Mercedes even faster than it already was and the S76R is what Renntech is calling the “perfect W140.”
Read More: Making a W221 out of a W140 Mercedes-Benz S-Class
Under the hood of the S76R is a heavily modified (yet still naturally aspirated) version of the 600 SEL’s 6.0-liter V12 that was bored and stroked out to 7.6-liters. Its aided by an ME-1 engine management conversion installed together with a handmade wiring harness and RENNtech ECU tune. The result is a healthy boost from the stock V12’s 402hp (408 PS) and 428 lb-ft (580 Nm) to 615 horsepower and 703 pound-feet (952 Nm) at the crank.
Renntech didn’t stop there as the original model’s 4-speed automatic was swapped out for a 5-speed auto transmission, and a OS Giken limited slip differential. Renntech says that with these mods, the 4,800 lbs (2,177 kg) German sedan can hit 60 mph (96km/h) in the low 5-second range while topping out at around 155mph (250 km/h).
To aid in the experience, Renntech has added some supporting modifications to the S76R as well. They include a custom, handmade stainless steel exhaust system with quad mufflers and sport catalytic converters that not only increase power but give the V12 a louder and meaner snarl as well.
The car was fitted with a bespoke AMG Carbon Ceramic braking system with six-piston calipers on the front axle with four-piston calipers at the rear, while it rides on one-of-a-kind forged Renntech aluminum wheels measuring 19 x 9″ in the front and 19 x 10.5″ in the rear with 235 / 45 (F) and 285 / 35 (R) Michelin Pilot Sport 4 S tires.
Inside the cabin there’s a completely custom interior and trim set. Above the occupants is an Alcantara headliner with carbon fiber inlays. A leather dashboard sits ahead of everyone and the seats are finished with diamond-stitched leather upholstery. In fact, the rear bench seat has been replaced altogether with a pair of fully-adjustable individual rear seats. Renntech has even added a modern sound system with iPhone integration.
While this example is a one-off, Renntech says it will happily build your own custom W140 Mercedes S-Class with all these mods and more, though it did not provide any details on pricing.