Quote Originally Posted by OldF View Post
In the past a centre diff with asymmetric torque split was in use. The example is from “few” years back in the 1986 Portugal rally which had both tarmac and gravel stages.
The Lancias had a front/rear torque split 25/75 on gravel and 30/70 on tarmac.
The torque split for the Audis was 40/60 all the time.
Malcom Wilson had with the MG Metro a torque split of 35/65 on tarmac and 45/55 on gravel. The other Metro drivers had 25/75 on tarmac and 35/65 on gravel.
The Fords had a torque of split 37/63 all the time.

The active front and rear diffs was banned from the beginning of 2006. If I recall correctly there was also talk about banning the active central diff but at least the drivers wanted to preserve it because it enabled the use of the handbrake. https://en.wikipedia.org/wiki/World_Rally_Car

The rule changes from season to season can be followed on http://juwra.com/seasons.html
The ban of the front and rear diffs is not on Juwra’s 2006 rule changes http://juwra.com/rules_2006.html
Jonkka must have missed it for some reason.

All the manufacturers attending the 1995 wrc season had an active centre diff by the end of the year.
Even looking at the era I like the best, the Group A days between say 88 to 94 its seems that everybody just made all the diff stiffer than hell..Front , center, rear, crazy stiff.. Now add wide tires and tight narrow tarmac roads and you have a car horrible to try and do tight corners...

There there was toque split on those cars...who know but I DO know that many in the Sierra/Sapphire/Escort Cossies did go to 50/50 and to quote one multiple BTRDA Gold Star winner, Pete Doughty, "It handled like a pig, like the old Quattros but 50/50 was the fastest so that is what you run"