Ok, not to beat this dead horse any more, but I've been doing some digging. It seems that
iconoclast is correct. Even though these engines are similar, that similarity really only applies at the basic level. The M50i's N63B44T3 (N63TU3) does not have the capibilty engineered into it to handle the increased boost to get to 700HP. Not that it
can't, but it surely wasn't designed with that kinda thrust in mind. The M variants (S63)
do have that capability, though. They say the Devil is in the details. To me, the S63 has more details.
The articles below go into fairly good detail as to the differences between the N63 and the S63. I know they are 2 years old, but I assume what was true then is now, as well. Maybe not. Maybe in those 2 years, the gap closed considerably...?!?
I would love to have a tune, but these articles definitely give me pause...for now, lol.
https://www.caranddriver.com/feature...them-the-same/
https://bimmerlife.com/2018/08/23/n6...evolution/amp/