Dueclaws

I found a thread that compares the M278 engine to the new BMW N63:
"Twin Turbo V8 engine design, tuning, and power potential comparison: Mercedes M278 (W212 E550) versus BMW N63 (F10 550i)"

In the thread, RennTech posted the results from their newest M278 RT tune and had other comments about the M278 power increases: here's a clip from RT's comments:
"It was additional tuning done on stock CLS550 w/slight extra limiters load increase done in Jan 2012. If a customer it's willing to go the extra step, the M278's can reach mid 500's whp. That would be very nice for the +2012 E550 Biturbo Coupe =)" "This motor will handsomely do over +500-570whp with the right upgrade"

A dyno graph is attached, but this isn't for the mid-500's wheel horsepower.
D.C.

Used2be

Interesting article, thanks for pointing it out. I doubt I'll ever go past the ECU tune and that exhaust/turbo swap would be more effort and $$$ than I'd want to throw at a daily driver. But there is great potential there for those who wish to pursue it!

I thought I'd add my admiration for the design changes BMW brought to the N63 motor. To think outside the box and reverse the normal airflow path through the cylinder head is an interesting design step! I wondered at having two turbos being fed by the exhaust, all in the middle of the two banks of cylinders, and whether that would cause any heat problems? I found a parts fiche online and there are multiple layers of heat shielding around that part of the engine, so I hope that BMW has controlled the intense heat being radiated from a central, confined location. I wonder if the reversed airflow through the cylinder head would have been feasible with the turbos prior to the development of direct cylinder fuel injection for four stroke motors?