So whats the diference with an electronic diferential AWD? such as the one the 997TT already has, and was first introduced in a street car by Porsche with the 959. It has a diferential in the centre made up of interlocking clutch plates, that are controlled electronically, based upon the different sensors in the car that judge the vehicle's dinamics and need for torque to be transmited to the front wheels or not, the clucthes in the differential engage or not. Hence have RWD normally and electronically implementing AWD when you need it.
" Ferrari's new insertable four-wheel drive system is based on the traditional RWD layout, where the main driving wheels are constantly connected to the engine via the usual gearbox and clutch arrangement. The second pair of wheels are selectively connected via their new insertable transmission system.
... The insertable transmission system also transfers motive torque to the front wheels when a difference between the rotation speed of the front and rear wheels occurs; ie, essentially when the driving wheels slip".
... Technically, the secondary clutch, which controls the provision of torque to the front wheels, is controlled by an electronic control unit."
They call the center diferential the insertable transmision, which consists of an electronically controled clutch. To me this is just an electronic diferential system with a fancy name to sound new and original
With the amount of power these cars nowadays are having I think its a great idea, besides this type of AWD system would be the one that would respect the RWD handling characteristics better than anyother AWD system I would think, something I think is important for Ferrari buyers.