BMW’s Megacity is set to shake-up how the cars in the company’s range are constructed in the future.



Life and drive construction

The Megacity’s construction is split into two sections, dubbed ‘Lifedrive’. The Life section is the carbon-fiber passenger cell and the Drive section the aluminum chassis.

BMW has developed its own cutting-edge technology, using special heated moulds and sophisticated resin injection systems in order to mass produce the carbon-fiber pieces.

Aluminum Chassis

A longer wheelbase can be achieved by extending the twin aluminum extrusions that run front to back. Wheelbase flexibility

The MCV’s chassis is made up of aluminum castings and extrusions, which offers tremendous rigidity and greatly aids ride and handling. The chassis’ front end acts as sub-frame for mounting the front suspension and steering. It’s also the crash structure for the car.

This lab crash test picture (below) shows that the aluminium structure has managed to absorb nearly all of the energy pulse, minimising damage to the carbon monocoque. It will be easier and less expensive to repair the aluminum front structure than the monocoque.

Flat-pack battery

The battery pack is mounted in the chassis, under the cabin floor. Rear doors that stretch

It’s also ideal for building a longer version of the MCV because the front door can remain the same and only the rear door has to be stretched.

Electric motor goes here

The rear of the chassis is a cast aluminum ‘box’ which will house the MCV’s electric motor. Using a range-extender power-plant would allow the battery pack to be smaller, saving weight and cost.

Range-extender transmissions are probably most likely in future luxury BMWs. Using the battery pack as a power buffer means that high performance can be achieved with a very small engine.

Transmission

The MCV’s electric motor and single speed transmission are mounted at the rear and drive the back wheels.

Crash-friendly carbon monocoque

Tests have shown that in side impacts the MCV’s monocoque suffers exceptionally low levels of intrusion, partly thanks to the structural foam in the sill’s void.

Even though the damage is significant, BMW claims this monocoque could be repaired. Using the same aluminum chassis for a wide range of larger cars would also save a great deal of development money. Only the unstressed carbon-fibe passenger cell, seating positions and exterior styling would differ.

Source Autocar.co.uk