Originally Posted by markk
a bit off the mark there pal , the torque split is done around the vc with the planetary gears pal, has nothing to do with the drop gears, as for the vc, the road going models were no where near that high, less than 50nm mate,
In the old days, grp'n' esc with the standard box used a 50nm centre diff as Mark says.
There were lots of variations on the Saph's, the Quaife was the most popular after the old 'sport' box, both were based around the MT75 transfer box so had similar options with regard to split. Generally tarmac cars ran the viscous arrangement with the 50/50 being used on the gravel cars.
It's similar with the front and back diffs, different drivers use different ramp angles in the diffs, all depends how they like to drive.
If you've ever driven a car with a 50/50 split you'd certainly want to understand transmission better, they have to be driven with extreme commitment as they push on in corners tremendously.
The later modern rally cars are a compromise between traction and drivability, as they vary torque split and ramp angle at different times during acceleration and deacceleration to maximise the two...
R & D boxes were again based around the MT transfer box AFAIK, never actually owned one but they have ventured slightly into electro mechanical centre diffs as well.
HTH
Ian