RENNTech was founded in 1989 by Hartmut Feyhl, a man whose resume includes 10 years at the AMG βwunderwerksβ in Germany, where he helped build the very first W124 300E 6.0 AMG, better known as the “Hammer”. After spending two years as the technical director for North America, Feyhl ventured off on his own. RENNtech quickly built a reputation for performance without compromise; the RENNtech E7.4RS is a prime example of this.
Car and Driver Magazine ordered the W210 RENNtech E7.4RS as a test vehicle for an article they were planning to write about high-performance tuning. The project was carried out in 1998, and the E7.4RS was completed after several months of extensive modifications and testing, resulting in a monster of a car that would make even the most indifferent petrolheads tremble with excitement. Car and Driver featured the E7.4RS in a cover story in their August 1998 issue, showcasing RENNtech’s engineering capabilities, including pushing the limits of what was possible with a saloon at the time. After its completion, it immediately claimed the title of βfastest saloon in the worldβ.
You see, the E7.4RS was not your ordinary Mercedes-Benz W210. It was powered by an aluminum M120 6.0 V12 engine, as used in the Mercedes-Benz SL600 and CL600. However, RENNtech wasn’t satisfied with the stock engine, so the displacement was increased from 6.0L (5,987 cc) to 7.4L (7,367 cc). They achieved this by increasing the bore diameter of the E7.4RS engine to 97 mm from the original 90.9 mm in the stock M120 engine. After which, custom-made cylinder liners were installed in the engine block, and the stroke length was increased to 100 mm from the original 84 mm, resulting in a compression ratio of 10.0:1. A custom crankshaft and connecting rods needed to be designed to withstand the increased power output. The cylinder heads were extensively modified and fitted with high-performance camshafts and valves to improve airflow and power output. The intake manifold was also modified to improve airflow, and the engine was fitted with a custom-made stainless steel exhaust system with high-flow catalytic converters. They upgraded the Bosch LH-Jetronic electronic fuel injection system with larger injectors and remapped the engine management system to take full advantage of all these upgrades. The combination of all this resulted in a fire-breathing monster with 620 horsepower at 6,000 RPM and 625 lb-ft of torque at 4000 RPM. This catapulted the car to a top speed of 318 km/h (197 mph). It achieved 0-100 km/h (0-62 mph) in an incredible 3.9 seconds. Yes, RENNtech does not compromise on performance. For our American friends, the quarter-mile time was reported to be 11.4 seconds at 129 mph.
To manage all this brutal power, the M120 was mated to a five-speed automatic with manual mode and RENNtech-tuned software for faster shift times and increased torque capacity. A modified differential with a different ratio was installed, as was a custom suspension setup with RENNtech-tuned Bilstein shocks, Eibach springs, and larger anti-roll bars. The brakes were upgraded with six-piston front calipers, four-piston rear calipers, RENNtech slotted and cross-drilled rotors, custom-made stainless steel brake lines, and RENNtech brake pads. The suspension and brake setup were key to the E7.4RS’s exceptional performance capabilities, and they helped to set the car apart from its stock counterparts.
The E7.4RS had a unique exterior with a purpose beyond its good looks. The front bumper, side skirts, rear diffuser, and rear spoiler were all custom-made. These aerodynamic modifications were designed to increase downforce and reduce lift at high speeds. A set of RENNtech forged wheels were also designed specifically for the E7.4RS and were 19 inches in diameter. Pirelli P Zero tires were selected for their high-performance characteristics and were sized 255/35ZR19 in the front and 285/30ZR19 in the rear.
They did not overlook the interior, although it wasnβt as extreme as the technical changes. It had a custom interior with black leather and Alcantara upholstery, RENNtech-branded floor mats, and a Kenwood audio system with a CD player, AM/FM tuner, and a 10-disc CD changer.
Itβs clear the W210 RENNtech E7.4RS was an exceptional achievement in high-performance tuning, and the modifications made to the engine, suspension, brakes, and aerodynamics were all designed to work together to provide an unparalleled driving experience. The attention to detail and quality of the components used in the build of this vehicle are a testament to RENNtech’s commitment to excellence in high-performance tuning.
