It is easier to play dumb and see if someone who has had a similar problem arise can shed light on the situation. There are no faults appearing in attesa ecu, the pumps work fine and are pressurizing, there is new fluid in system and is bleed correctly. The tires are great and never had a problem before, same with suspension. Car has run 11.2 @ 124mph on exact same set up. When the car is in the air all 4 wheels drive, but on the road drop the clutch and watch only the rears light up. As far as I am aware from everything I have read on here I have tried to eliminate most of the problems. Yet I am not sure as how to test transfer case and know that it is the multi clutch system inside that is letting it down. I was just chasing ideas that I may have missed by people adding suggestions. My main suspicion was the transfer case but wanted any light shed before I put the car on the hoist and remove the box.