[Trevor]

Originally Posted by NiftySVX

[QUOTE}The torque split is calculated by a map, I don't see anyone who has suggested otherwise. However, it is clear that a difference in wheel speed between the speed sensors is how it detects a slipping condition. It says that plain as day in the repair manual. A normal driving http://www.subaru-svx.net/forum/imag...mad.gifpattern is calculated by the principle of predictive modeling, as I stated before. A difference in wheel speed between speed sensor 1 and speed sensor 2 is how wheel slip is detected. It is a very simple system, requiring little to understand the basic operation, providing you have a grasp on the aforementioned modeling.

I do not think that the explanation in the manuals necessarily has relevance. Often the explanations are simplified rather than the complete process being explained, which is what Phil is outlining as follows:-

“I think the TCU is looking at how fast the input shaft is turning compared to the amount of throttle applied. The sweet spot of the map is in the middle, when you are travelling at a steady speed, high duty cycle = power up front.

If there is wheel spin then there will be less resistance to the engine's torque and therefore the input shaft will be spinning faster relative to the amount of throttle applied. The map lookup gives a lower duty cycle and power shunts to the back.

Alternatively, when you are accelerating against the car's inertia, the input shaft will spin slower relative to the amount of throttle applied. Again, the map lookup gives a lower duty cycle and power shifts to the back.”

As I see it the point Phil makes, is the inclusion of throttle position within the equation, rather that the simple use of front/rear wheel speed difference. He will no doubt explain/comment further.