Re: DPC & SCI: 2 new chassis & drive systems by BMW
Interesting - though I'd like to see a bit more detail information and perhaps some diagrams.
My interpretation of this is that DSC is being phased out as an influence in the "differential locking" (xDrive uses the DSC to stop a spinning wheel - thereby providing a limited-slip differential effect) activities and a new electro-mechanical system will assume these duties... DSC will resume the primary role of stability control.
Have I got this correct, Eni and Scott?
The electro-mechanical diffs - are these both on the centre and rear differentials?
Sounds a lot like Honda's SH-AWD System that not only distributes power infinitely between the front and rear axles but also laterally to the left and right side of the car.
To make it clear: yes, Martin, you are correct.
DPC (electro-mech diffis on rear axle) can distribute the power / torque sent to the rear axle independently to rear left or rear right wheel (from ratio 0 to 100 and vice versa) - depends on traction situation.
Eg. if 100 units of torque is available for rear axle, current distribution is fixed in 50:50 ratio. DPC will be able to distribute these 100 units variably between rear wheel - and also applied extra torque if needed. So theoretically all 100 units (or even more) can be sent to eg. left wheel only.
In current configuration DSC has similar function, yet it only blocks wheels without being able to transfer the remaining torque to the other wheel.
Eg. those 100 units is available at rear axle: 50 at right wheel, 50 at left wheel. When DSC blocks the left wheel by eg 50% - reducing the torque to 25 units, the torque on the right wheel remains at 50.
With a help of new SCI system now the additional torque will be applied independently of acceleration pedal position to the un-blocked wheels.
Eg. 100 torque units at front axle - 50 left, 50 right wheel - left wheel gets blocked by 50% (so to 25 torque units remaining) while the right one can get additional torque to its 50 units.
So, DPC + xDrive + DSC with SCI = Dynamic xDrive.
DSC+SCI will control the front wheel traction, while DPC will be responsible to control traction at rear wheels. Since active differentials will be on rear axle only, while front axle traction (no active diffs on front axle) will be controled via DSC+SCI only.
I guess both new system can be either paired with xDrive or not.
So facelifted 5er with xDrive already has SCI system on board, while DPC is expected to be launched soon.
There will also be some RWD models equipped with PDC only - acting like LSD.
Advantages of Dynamic xDrive / PDC: sharper steering, better handling, better traction, better micro-split, more stable ride (less steering corrections) => even further enhanced driving dynamics & more driving fun & better active safety. Meaning: you'll be able to drive even quickly & more dynamically yet more safely through twisty roads (or quick lane changes).
Advantages over similar systems: PDC can not only operates under load, but also actively distributes torque during thrust operation and when the clutch is engaged.
