The only turbo kit I know is the VF Engineering that seems to be sold by just about every parts distributor. Its apparently (not tested) a very complete kit that should be plug and play.

If I may recommend you try one thing before going to a turbo kit or supercharger : find a 4 wheel dyno, take the x5 as it is and make sure you've got all of the original horsepower or close enough. I've known a friend wanting more power simply because his car needed a good and complete service to win back 20% lost power.

:DGreat suggestion, I totally forgot about that :D i will find one and update the post later, for now thanks for the great help
I appreciate it.

Cheers!

This maybe off topic or idea but did you look into a manual diesel 3.0 engine and twin turbo it I have heard of guys from Canada who have done this.

I just now finshed replacing transfer kit chain and seals and that was a 1000$ fix, how is that compared to the USA rates and prices ?