[walile]

I often find that debating on Internet forums is a waste of time. Yet I also don't want people to come here and get misinformed or think that this forum lacks fundamental automotive knowledge. Nothing personal here.

Now, just because you make a statement, that doesn't make it true. What you are saying simply does not make sense.

Originally Posted by drob23

Simple...rear diff eliminates understeer as it uses a feed forward control structure. You can easily anticipate torque appropriation based on inputs regardless of disturbances.

It's not the "rear diff" part that eliminates understeer, after all every modern cars have a rear differential.

Of course it's the torque vectoring that reduces the understeer, and its implementation necessitates a computer controlled active differential or using rear brakes like Porsche. In theory you can have a front active diff with torque vectoring on a FWD car.

Originally Posted by drob23

The purpose of the center differential is to maximize traction regardless of performance, the only way to improve performance is to increase the rear bias via changing the nominal gearing.

What is the "Regardless of performance" nonsense? In an AWD system, the goal is to maximize the use of available traction to yield higher performance. They are directly related.

Increase rear bias is only beneficial if there are more traction at the rear. Otherwise we will just send 100% of the power to the rear aka RWD.

Originally Posted by drob23

And Audi uses the crown center differential, not a torsen (which cannot self lock).

You are correct that on some model like the RS5 it uses the new crown gear center diff. But I don't know if that change has trickled down to their entire model lineup.

It also doesn't change the fact that it is not an active center differential. So, it cannot proactive change power distribution as soon as it senses steering input. Of course when coupled with the active Sport Differential at the rear, it becomes less of an issue.