This is an extraordinary one-off example which has now been built at the Mercedes Rastatt plant and we have been informed that it will not go into production for sure….or will it? It shows the B-Class in a completely new light: a B 55 with a V8 engine and rear-wheel drive. The ultimate hot hatch and a possible new craze for tuners out there who will now see the rather docile looking B-Class in a different light. Rest assured some Malaysian will take a B-Class to a tuning house and have this conversion done once he reads this.
A 5.5-litre V8 developing 388 hp and 530Nm of torque was transplanted into the B-Class together with a seven-speed automatic transmission and the engine control unit. The latter proved to be quite a headache later on, as it had to be reprogrammed only to process signals from the driven rear axle. Mercedes engineers mentioned that the V8 power unit fitted amazingly well, and they were even able to use the original engine mounts. There were serious problems with the steering, but here too, harmony was restored with a number of modifications. The exhaust system was a clever combination of various replacement part items, and took the form of a twin-pipe system emerging at the centre of the rear end. This is where the one-off, christened the B 55 gets its typical, burbling sound – once the ignition key has been turned, all heads in the vicinity are guaranteed to swivel simultaneously in the direction of the B-Class.
Intensive perusal of parts catalogues also solved the second major transplantation problem, namely the drive axle at the rear. It emerged that the rear axle of an older W 210 series E-Class would be a very good geometrical fit. They designed a sub frame, which extensive forming and welding work allowed to be integrated into the B-Class body shell to receive the new rear axle. Elegantly concealed within the sandwich floor, the prop-shaft of the E-Class also fitted into the B-Class with no further modifications.
For the brakes the team obtained parts from the the C32 AMG. Perforated and internally ventilated disc brakes in size 345 x 34 mm were implanted at the front, with perforated and internally ventilated disc brakes in size 300 x 30 mm at the rear. The system was combined with striking 8.5 x 18 AMG sports wheels in a five-spoke design shod with 235/40 ZR 18 Y tyres at the front and 9 x 18 wheels with 255/35 ZR 18 Y tyres at the rear. The maximum steering angle at the front axle was limited to suit. The team had recourse to a typical item from the tuner’s toolbox for the suspension, installing a coil-over suspension by K&W.
Where the interior was concerned, friends from the training workshop in Sindelfingen were able to help, providing Alcantara linings for the A, B and C-pillars as well as a roof liner in the same, luxurious material. The seats in a leather/Alcantara combination were provided by the specialists at Johnson Controls, who are located on-site in Rastatt. The finishing touches were added to the B 55 in the paint shop of the Rastatt plant. In trendy white with dark-painted radiator louvers and smoked headlamp lenses, the B-Class cuts an imposing figure but only gives a discreet indication of the power pack concealed beneath its bonnet.
The project team headed by foreman Würz are particularly proud that at 1620 kg, the weight of the B 55 is only around 180 kg greater than that of the original car. Which means that impressive performance figures can be expected. Würz: “We have not made any measurements yet, but we should manage a sprint to 100 km/h in under six seconds.”
