dual pump setup

[m dizzle]

I want to run a dual pump setup, so that I can basically run the tank dry if needed. I bought the larger capacity tank as I had the smallest one stock. I didn't realize that the fuel return nozzle on the driver's side of the tank has an internal tube which dumps into a swirl pot on the passenger side, where the stock fuel pump sits.

So I'm putting an E46 S54 pump there, and the secondary transfer pump on the driver's side.

I've narrowed my plumping and wiring down to 2 options (based on what I already have in the garage fuel pump wise) and it really comes down to fuel flow which is where I'm hoping someone has experience with this.

Which flows faster, the fuel return from the motor or the fuel output from the transfer pump? Obviously its dependent on load - at full throttle I assume the transfer pump will have a higher output than the return from the motor....but lets just assume highway driving. Is it even close or is the engine return flow greater?

[nando]

the return flow should be less - it can't be more than what the pump is sending to the engine, some of the fuel will be used there and whatever's left gets sent back to the tank. Now, the amount that is returned is usually far greater than the amount that is used..