Multi-stage EFI pumps?

[MaineShark]

I've seen some mentions of people running multiple fuel pumps. That is, a pump (lowe-pressure, high flow, I assume) at the fuel tank, running to a surge tank, from which a second pump (typical high pressure EFI pump, I assume) draws.

This seems interesting to me, both from a safety standpoint (if the surge tank and high-pressure pump are in the engine bay, then the majority of the plumbing will be at low pressure - less likely to leak), and as a way to prevent the pump from being starved, without opening the main tank to add baffles (the fuel can't slosh as much in the surge tank during cornering).

At least, that's how it seems to me...

Thoughts?

Joe

 

[Ken]

Hmmm... We're gonna see what people think of my system, eh Joe?

 

[MaineShark]

I just took a look at your webpage, to see what you meant. I think you have a game-plan. While I'm not an expert, I do think that the reduced pressure will allow your stock pump to flow more.

I'm really liking this idea, since the possibility of losing fuel in a turn is one of the things I like lease about EFI.

Now I'm wondering about something like a high-flow, low-pressure (carb or TBI) pump mounted in the tank, and a high-flow, high-pressure pump mounted into the surge tank. If I can stick with in-tank pumps, I hope I can keep some of the noise down, since I don't like fuel pump noise.

On the more technical side, I'm wondering about the possibility of somehow varying the speed or duty cycle of the first pump in response to demand, so not as much fuel is needlessly pumped to the surge tank, only to flow right back to the fuel tank.

On the other hand, I could take advantage of that and install a fuel cooler in the line, so that the continuous flow of fuel would actively cool the fuel in the tank. (speaking of which, I think I'd better find someplace other than the engine bay to mount the surge tank, so I don't end up cooking the fuel)

Where and what size fuel filters, is also an issue...

Lots of possibilities. Luckily, I have lots of time before I'll be ready for fuel injection.

Joe