Non-linked AWD dyno's

This is a question for anyone who has a non-linked AWD dyno, any cars that your unable to run on you dyno and why? Looking to up-grade from my 2wd set up and really stuck on if I should get a linked or non-linked AWD set up. Looking for the horror stories.

Thanks everyone

I run a dynapack 4wd hub dyno which is unlinked, works great, however I do have issues with any car which runs a variable center diff or a car which has slightly different front-rear diff ratios/transfer case ratio. The hub rpm front to rear will be out and the dyno will not allow the vehicle to go into a ramp run until they are within tolerance of each other. Or if the center diff/transfer is slipping the car will oscillate quite bad during a run making it impossible to do any tuning.

I haven't got any experience with linked dyno

Thanks for your input Chris, what car was that you had issues with?

Demand based AWD cars can have an issue with the DynaPacks, such as Volkswagen/Audi products that use a Haldex style coupling to apportion drive to the rear wheels based on rotational differences, this is masked somewhat on a roller dyno as the inertia of the rollers helps to maintain the rotation of the wheels and stops the Haldex system from cycling in and out of lock constantly.

I can't remember exactly what cars but most like BlackRec mentioned VW/Audi, a lot of Euro, also Ford Territory and some Mitsubishi evos etc where people have fitted different front to rear diff ratios