A technical article on drivetrain setups is hard to find. I'm confident in your google skills to find it. There probably is an SAE article somewhere with a hugeass spreadsheet full of numbers and equations to make your heart content. In the meantime, I offer this Canadian Driver article. A good read on the pros and cons.

Also, to cement my hatred of Nissan North America for not releasing THE best AWD system on the planet. Bitches. I give you this:

The GT-R uses an electronically controlled all-wheel-drive system (similar to Porsche's 959). A 16-bit microprocessor monitors the car's movements a 100 times per second, including wheel rotation and lateral as well as longitudinal acceleration. When slip is detected at a driving wheel, the system electronically distributes torque from this spinning wheel to one without slip.

In this case the electronic AWD-system offers the advantage that actions are enacted much faster than by a viscous-coupling-system (we're speak-ing of hundredths of a second here). In standard setup, ATTESA-ETS distributes the torque to the rear-wheels, but when slip is detected on one of those rear-wheels, it can distribute up to 50% of the torque to the front wheels, i.e. it can adjust the front/rear torque-split from

anything between 0:100 to 50:50. Among the rear-wheels, an active LSD can further distribute the torque from one wheel to the other if necessary. Due to this setup, the Skyline GT-R can even drift, although it is an AWD car. Source

There you have it. Technology at its finest. A RWD car that launches and handles like an AWD car in the twisties. The Skyline's ATTESA system is king - IF you can stomach the 90K+ sticker price... as for me, I'm quite happy with my viscous coupling. Nothin but good ol LSD for me. Wait. That doesn't sound good.