i had a crazy idea while watching powerful 4wd launching! basically with 4wd you cannot monitor the wheels for wheelspin %. this is how ultra effective 2wd motorsport traction control works. in 2wd TC the rear wheels which have 100% traction are monitored then if the front wheels start to slip more than a set % power/torque is reduced and controlled to limit excessive slip.
with 4wd you do not have a wheel that has 100% traction so TC is unworkable buy monitoring any 1 wheel then controlling power to bring the other excessivly spinning wheels to the same rotational speed as the monitored wheel.
Now my idea is to introduce a fifth wheel! this could be a very small lightweight wheel that is simply resting on the floor that will give a 100% true rolling traction wheel speed obviously with multipliers to make its number of turns equal the car wheels, now we monitor that 5th wheel and control power/torque to make the 4 car wheels have set % of wheelspin and hence max traction!
I searched for such and system but did not find anything, obviously if this is a workable idea some clever person would need to design it. thats thats what i thought anyway.
what do ya think?

 

Speak to Racelogic, when I asked them about it for my Subaru that was starting to get rather wayward they said their system could work for 4WD just using the wheel speed sensors, but I never got around to it.

Presumably they average the wheel speeds between all four and look for the outliers.

 

yes i have used the racelogic version but its no use having all 4 wheels equally spinning at 60% traction loss !
maximum traction is at 18-20% for fwd cars . there must be an optimum % for 4wd cars agree ?
the only type of 4wd traction control i know of only match the 4 wheels to each other using various different methods applying brakes etc! that still does not give max traction

 

up for the late risers