In the older DCCD system as the rear tyres break traction it would send more and more torque to the rear. much more than the stated 65% rear torque bias. This sounds like fun (and it is) but when you are getting into it, suddenly getting more rear bias if you manage to break traction in a corner can make the car unstable and hard to predict when you want to power out of a corner.

in my06+ the DCCD coupling is combined with a viscous coupling. It reduces the torque bias, but also maintains the torque bias closer to the 41:59 specs if you break traction in a corner. So you still get the improved turn in of having more rear torque bias without any surprises when you put the power down.

Having said that the older system is still fine if coupled with a good automatic controller.

But in the newer system you can get away without running any controller. Youd only really NEED the controller when you want to get on a dyno

I bet its really improved the performance of the shelf you've got it sitting on.

__________________
RS Liberty - Because WRX's are only good for parts...