Slot.it CA29a Audi R18 e-tron quattro n. 4 test Le Mans 2013 Marco Bonanomi

Driver : Marco Bonanomi

The R18 e-tron quattro is a hybrid version of the R18 ultra, named after Audi "e-tron hybrid technology", which consists of a front mounted electric motor working in synch with Audi integral traction system. A diesel engine provides power to the rear axle both on the Audi e-tron as well as on its more traditional sibling Audi R18 Ultra. The energy storage unit for the electric motor is a flywheel system designed by Williams Hybrid Power. The Audi R18 e-tron belongs to the 2 megajoule (2MJ) category.

A four wheels drive system, as per the Le Mans regulations, can only be used on hybrid cars if the electric motor is mounted on the opposite axle of the traditional motor. Besides, electric traction may only be available at speeds above 120 km/h (75 mph), to limit the traction advantage of a 4WD system at slow speed. Management of electric motor and of drive train is completely automatic.

On its Audi R18 e-tron Slot.it has created a 4WD system which is truly unique and innovative. Traditional slot cars with four wheel drive, having no differentials, invariably show poor top speed and bad handling. In the Slot.it system, a toothed belt provides power to the front axle through two micro pulleys which are coupled to the left wheels. Here, the work of two clutched bearings (unidirectional bearings), mounted between the front wheels and the front shaft, makes it possible to transmit positive torque only, removing any braking torque, so that the model, while retaining real 4WD traction, keeps its top speed on straights and handles like it should when turning.

This car reproduces the test n.4 pre-Le Mans 2013 model, driven by M. Bonanomi. It comes with the long tail that was chosen by Audi for the successful 2013 Le Mans campaign.