J, I find this hard to believe.Nope. The S85 uses two fuel pumps pulse-width controlled by the DME. It would be cheaper to replace the stock DME with a Motec and get it working (and thats $10k easy) than to get the stock DME and wiring modified to control aftermarket pumps properly.
I have been down this road with my build and the two fuel pump and DME was a bit of a hurdle, the cost I was given to go with either an auxiliary pump and a custom fuel line was a little out of my budget at the time. I think I was quoted 5k total but nowhere near 10k.
I may still end up having to do this later next year once I push more power as the fuel issue may be my next hurdle.
J, I find this hard to believe.
the DME Should be able to control the fuel pumps w/o issue as long as there wired in correctly
an AEM infinity-10 (miles ahead of the Motec offering) is about $3500 and it Replaces the BMW DME...Tuning it is NOT 5K and a custom wiring harness is also not 2k
so yes it can be done.
we have done it on the S54 M3 and the S65 Platforms...i think no one has tried it for the S85 platform but its not very different
Question for the OP is why do you feel you need a HP fuel pump? just upgrading the fuel pump alone wont help much until your certain the injectors can flow more.
whats your goal or thought process behind the "why"?