Article: VTT working on 1200+ whp 100% E85 ethanol capable BMW N54 fuel system

[The Ghost]

True I didn't consider the volume in the return line prior to starting a run. Assuming the two primary pumps are oversized enough to push that fuel back to the bucket. Which may or may not be the case depending on the power level and fuel pressure.

net/net I'm happy we've at least done some sort of a reasonable analysis on this. It would be nice to get actual flow numbers through the factory and 455 in tank post siphons and filter. The OEM pump probably is very limited in that regard so I'd consider the 455 in tank a must to attempt this setup. I think if you were going to go this route a 3l surge tank would make more sense.

It is in my two posts that I tagged you in explicitly and in the video you didn't watch

Yeah the numbers are all theoretical anyway.

Reading the Radium page, 2L is the fluid volume with 2 pumps; add that to the fact that you don't want to deplete tank till the point you are counting on the fuel in the return lines (defeats the purpose of a surge tank).

Say 1.5L effective volume will give you ~20s with the OEM pump and still about ~55.3s with the 455.

And 55s at sustained WOT, no lift, is plenty for nearly all scenarios.