chief-long-shin

I just thought i would pose a quick question to see the advice given....

As the wrx is my first 4wd car i am not a 10% sure on how they sort themselves out in adverse conditions. I managed to find a large open space completely coated in ice and tried the following;

Driving around in a circle i eased a little throttle on and initially the front wheels hold on then the back spins the whole car round. Great fun as it is i was curious as to how to get the car drifting insteaad of donuting.

I understand this is difficult in the 4 wheel drive however it was difficult to stop the car from spinning. Lock to lock did nothing and neither did varying the throttle.

How's it all done? I'm curious and as it nice and snowy at min i can avoid the screwed up diffs....

4x4chris

i think the theory is to keep the power on and use lock to sort it out....
... bit of an art im afraid... best place to do it though is like you were, nice empty carpark... full of ice so no tyre damage either!

wish it would hurry up and settle down here so i can go and have some fun!

chief-long-shin

What part do the diffs actually play in the drift?

I really dont have a clue, do they just distribute the power to wheel which has the most grip in order to correct?

4x4chris

A 'normal' differential just allows the wheels to turn at different speeds.
On a FWD or RWD car you need one differential between the driven wheels to account for the fact that on a turn, the inside wheels will be travelling a shorter distance than the outside ones.
on a 4WD car, you need one diff between the two front wheels as above, and the same again for the back wheels. But you also need a centre diff to account for the fact that the front driven wheels will travel a different distance to the rear ones....
the problem with this type of 'open' differential is that it will only apply the same amount of torque to each wheel, so if you had one wheel on ice and one on dry tarmac you would only get as much torque applied to both wheels up to the point of the one on the ice spinning.

Now, a Limited Slip Differential (LSD) (im not sure what scoobys these are on but it is relevant to this....). This will allow torque (various ways of doing it using clutches, or viscous couplings, Torsen etc) to be applied to the non-slipping wheel.

sooooo a LSD (like all diffs) allows one wheel to spin at a different speed so you can corner... up to a point.. (the 'limited' amount of slip)
If there is too much slip then both wheels will start moving at the same speed. Too much throttle would start gripping both wheels (for example in a corner).
If you had enough power that would then cause both wheels to begin to spin.
- You would find your self in oversteer. Drift ahoy!

There are many different types of LSDs, 1, 1.5 and 2. I think 2 is best for drifting oversteer madness. but im going into too much detail already!

Hope this makes sense, and it is hopefully factually correct! Its just what ive picked up wehn researching the subject!

Chris