As the rules go, Porsches are built for speed and Mercedes are built for luxury. It seems no one ever explained the rules to Steffen Leitgeb of MKB Motorsports. MKB is located in a small peaceful town in Winnenden, Germany. Steffen is the public relations director at MKB and is fortunate enough to drive this '99 E430 Mercedes on a daily basis. MKB is a pure Mercedes hop-up shop that houses some of the meanest Mercedes-Benz in Germany. This E-Class is actually owned by MKB but Steffen has the pleasure of testing out new products on the vehicle. One of the main products he is testing out is an MKB-built powerplant flexing its latest engine performance upgrades. Though this car looks fairly stock-with the exception of the wheels and tires-it is capable of running flat-out over 180 mph on the street.
With less than 1500 miles on the engine, MKB decided it was time to give the Benz a power transfusion. What was once an OEM 4.3-liter V8 is now a custom-built creation displacing 6.0 liters. An extensive amount of time and money was put into the engine, testing MKB's new stroker kit encased in the 4.3-liter aluminum block. MKB punched out the factory sleeves and replaced them with ductile-iron models. The new sleeves now house eight 11.0:1 compression KS-Racing pistons. The 100mm pistons are 10.1mm over the 89.9mm factory issue slugs. A change in stroke was also needed to obtain the 6 liters of displacement MKB desired. The factory stroke is 84 millimeters, and the current stroke on the Benz now 94.8mm. The longer stroke was accomplished utilizing a custom MKB crankshaft and rods. The bottom-end 4.3- to-6.0-liter crossover was made possible using all MKB Motorsports one-off parts, which are soon to become over-the-counter affairs.
One of the key issues the MKB crew faced was designing the cylinder heads to hold up to the high-rpm demands that would be placed on the V8. To accomplish this feat, MKB decided to scrap all the existing valvetrain parts for rpm-friendly hardware. Once the valvetrain was disassembled, Steffen had the MKB engineers modify the ports and combustion chambers to create the extra airflow needed. This was accomplished by hogging out the stock exhaust and intake ports as well as reshaping the combustion chambers.
The redesigned head now houses a set of MKB polished and under-cut valves as well as a set of MKB valve springs and rocker arms. The factory bumpsticks were reground to a more race-spec design. Fuel compensation comes by way of two "very large and loud" Bosch fuel pumps with bigger injectors. Judging by the way Steffen filled out our tech sheet, we can tell he wanted to keep the fuel delivery in the Benz a secret. Under injector size he wrote, "Big, Ha Ha." Other than the pumps and injectors the only other modifications to the 180-plus mph Benz is a custom-programmed MKB ECU and Beru spark plugs.
With a fully prepped MKB Motorsports package under the hood, there was a need to build up the factory automatic transmission as well as beef up the differential. MKB technicians did an extensive transmission build-up to take on the high-torque 6.0-liter engine. The factory differential was removed and replaced with an MKB limited-slip model. According to Steffen, "The factory ECU also had to be modified for the transmission upgrade since the Mercedes' speed runs easily surpassed the factory mph limit. Once all the upgrades were complete, the E-Class was strapped to MKB's chassis dyno to lay down the law. In naturally aspirated trim, the Benz was able to lay down 425 horsepower. This is an incredible feat considering the original block was a 4.3-liter and the fact the Benz generates these numbers without the aid of nitrous or any form of forced induction.
Staying stuck to the pavement is the job for a good set of tires, a proper suspension set-up and a reliable set of brakes. Just like in "Days of Thunder," Cole Trickle relied on a good set of matched tires acquired from his crew chief to get past treacherous turn four. The E-Class rolls Dunlop 275/35ZR-18 SP 8000s mounted on 18x10s OZ Racing F1 Cup wheels. Suspension mods include a set of adjustable Koni shocks with MKB springs that set the vehicle's ride height 1.5 inches lower than stock. Upgraded Eibach sway bars also help the vehicle's handling. The Benz's brake system is quite clever, consisting of a set of cross-drilled rotors with a custom MKB adapter used to mount Porsche four-piston calipers to the factory Mercedes hubs.
Mercedes Benz is known for its luxurious exterior styling and comfortable, as well as eye-pleasing interior. Since the MKB flagship has a motor that would make the CEO of Mercedes jealous, you would think the exterior doesn't need any enhancements. That's when MKB stepped up to the plate and buffed-up the body of the E430 by replacing the factory fenders and quarter panels with MKB Motorsports' own flared-fender kit. As far as the interior makeover goes, Steffen decided to stay with OEM Mercedes parts with the exception of a set of MKB seats and steering wheel.
Europe houses a gangload of some of the fastest production cars, such as Porsche, Ferrari and BMW. Mercedes Benz is a company known more for its outstanding production and design than for building fast European production cars. Across the pond, MKB has raised the stakes by using its E430 to show a Mercedes isn't just for looks anymore. This Benz is capable of running 186 mph on pump gas, which is more than enough to stick it to a Porsche on the Autobahn. As matter of fact, MKB's Mercedes could probably have a Porsche for lunch while taking a family of five out to dinner.