Wiring a dual pump setup in a single pump car

[FredK]

The true r3vstyle engineering would be getting a short section of ABS tubing scrap/leftover from the local harware store's garbage bins, then epoxy two caps. This would be the learing step, before attempting an r3vstyle ABS tubing rollcage. :giggle:

hahaha

Maybe some cast iron pipe scraps and lawn sprinkler fittings will work in my application. :pimp:

[BimmerTim]

Understandable.

Mostly I meant that if you put a feeler up for them, I would be on the list, cost pending.

[BigD]

Thanks Lee! That's great news, will allow me to keep the stock level sender/wiring. I will put a late model pressure pump in the other side of the saddle - I know it'll probably be overkill flow but it can recirculate back, I'm mainly paranoid about always having fuel in the surge, until the tank is dry.

Should I throw a few blocks of foam into the tank too, just to have some pressure on the fuel from above as the level gets low?

[McGyver]

^^^^^

Only ftting a second pressure pump will not solve the problem of fuel starving that occures when the pick-up of the pre-pump is not submerged such as in long sweepers when fuel level is under half tank. A surge tank is the safest and most efficient way to solve fuel starvation as the main pump has a fuel reserve at all time.

ok, i see what you are saying. i didnt realize that you were concerned about getting fuel around a turn when the stock pump is pulling air. i will probably attempt this setup when i get around to putting in the 044 properly (i dont have a pre-pump for it).

[Massive Lee]

@ BigD

You are over doing it. All you need is one pre-pump going into the surge tank, which is feeding the main pump. Surge tank also receives fuel from the return, and what ever excess fuel in the surge tank is going back into the main tank.

[BigD]

Yeah you're probably right. But would I be hurting anything? I'd rather have pickups from both saddlebags.

[Jean]

Lee, if the car has two pumps can the res. be installed between the low pressure and high pressure pumps with just two lines going to/from it like the fuel filter?

[Massive Lee]

Hi Jean

I suppose that "res." means surge tank. Right?

It can work with two lines, just like a simle fuel filter canister, but you won't recuperate return fuel from the injector rail though, and the surge tank will empty itself pretty quick. Basically it'll be good only for a couple of seconds.

[Jean]

I didn't know you had to run all these additional lines, thought there needed to be a res with some fuel between the two filters and you are good.

So you need atleast 3 lines, one from the low pressure pump to the res, one from the res to the high pressure pump and the fuel return line routed to the res instead of the stock low pressure pump housing?

[Massive Lee]

4 lines required. You also need fuel return to the tank

[Jean]

There is already a fuel return line going to the tank via the low pressure fuel pump housing, so it can be re-used yes?

So, 1 going from the low pressure pump to the rest
1 going from the rest to the high pressure pump

1 going from the res to the low pressure pump housing/fuel return line
1 going to the res from the fuel return line?

Ok, 3 lines are fine and one needs to be added it sounds like. Why 2 return lines?

[Massive Lee]

[jlevie]

I run Enduros in my Spec E30 and being able to run the car down to fumes is an advantage. When using a 63L tank there are two viable solutions that will achieve that goal. One is to install a transfer pump in the left side and use it to feed fuel to the high pressure pump in the right side (what I have in my car right now). The other solution, that is probably more applicable in this situation, is to use a transfer pump on both sides, feed their output to a surge tank, and use an external high pressure pump to feed the engine.

[Jean]

Lee - thanks!

[joshh]

Damn good thread. Thanks for the info Lee...as much as I hate to say it, you are quite useful after all.