N57 and B57 differences - anyone converted twin to quad turbo?

[Del Funko]

Any guys on here know the N57 and B57 engines well?

I'm going about researching how much work would be involved in converting a twin turbo 313 PS N57D30T1 (say the one in my 640d) to the quad turbo 394 PS B57D30S0 engine.

Have tried a search and not found anything.. anyone done the conversion, or know the difference between the engines besides the 2 extra turbos?

Any difference inside the engines?

thanks.

[mkoesel]

Have a look:

https://www.etkbmw.com/bmw/EN/search...MW+640d/ECE/11
https://www.etkbmw.com/bmw/EN/search...W+750dX/ECE/11

Given that these are members of two completely different engine families, I strongly suspect that even within just the short-block, most parts are not carried over (though I admittedly did not study the above parts diagrams). However, assuming I am correct, it would no doubt be much easier to simply find a used B57D30S0 and go about swapping it into your car than it would trying to turn your N57D30T1 into the B57 somehow.

That said, taking another step back, it seems to me that you could probably get a third party ECU tune for your N57 and, with other bolt-on modifications, achieve 400hp and thus end up with similar performance to the quad-turbo B57 without changing engines at all. This would be much, much cheaper than trying to do either a turbo swap or engine swap.

[MARKPRIOR]

Depends on what you want to achieve i guess, i had remap only and nade 386bhp & 740nm of torque, figures of 400 are achievable with map only.