Ok can someone tell me where they sourced their torsen diffs for RC cars from?

The torsen differential uses the very basic principal that a worm gear can drive a regular gear but the regular gear cannot drive the worm gear.

When both wheels have traction the worm drive principal becomes irrelevant because the ground is giving the proportioned amount of turn into the diff centre( the gears move accordingly). When one wheel looses traction, the diff centre worms acting against the gear attached to that wheels drive gear, they cannot turn it, therefore locking that part of the differential and therefore the whole diff and all drive is sent to the other wheel. Because the forces are always there, it does not require any wheel slip to engage - the wheel without traction will simply be running at the same speed as the other wheel with traction.

You can change at what point it locks up at by the angle of the worm teeth. The gear with teeth having a tooth angle being closer to perpendicular to its own shaft, is the worm (the gear attached to the axle shafts in the case of a torsen).

This type of differential is very effective ina centre diff (transfer case) for All-wheel-drive aswell.

It also negates the use of heavier driveshafts and couplings to overcome issues faced with wind-up from locked axles etc.

Im open to criticism and comments!