Originally Posted by blacksheep
Why would you want this? Why not 4wd all the time?
On a 4wd when you apply the brakes to hard the front wheels will lock up. This will cause the car to push if you are trying to go into a corner. With the one-way the front wheels will free wheel so that only the rear wheels are doing the braking when you apply the brakes. So you still have to be carefull with the brakes because with a one-way installed the rear end can come around on you if you are not careful and smooth on the brakes.
Under acceleration both front wheels pull equally because there is no differential. This can cause the car to push out when coming out of very tight corners and acccelerating really hard.
Most people I have seen use one-ways are using them on fast flowing tracks where there aren't any tight corners so they don't have to be hard on the brakes. They definitely produce less drag on the car and come through sweeper corners like banshees.