They are ready to push forward to the next level though with a built motor option with the goal of 800+ horsepower to the wheels. Here are their built motor options:
Stage 3.4 will have options of 6564 or 6768 turbochargers
Stage 3.5 will go with a 6968 turbocharger.
Ok, that sounds good but saying you will do something and doing it is completely different. Thus far, we have yet to see built motor N55's making big power although that does not mean it will not happen.
Hopefully @Juan@Big_Boost_turbo will share more details (along with an improved web presence) but 2017 should deliver the most powerful N55's the BMW aftermarket has ever seen.