Wiring a dual pump setup in a single pump car

[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?

[BigD]

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

[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.

[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).

[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?

[BimmerTim]

Understandable.

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

[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:

[Massive Lee]

If you did make a batch, I would likely buy one.

"likely" is not enough to motivate me to produce them ;-)

I don't stock parts anymore. Or just very few. So, the way it would work is that if I have 10 commitments, then I will produce them. Price will be better. A few extras will be made, and available at 50% extra for those not in the list. I am doing the exact same thing with some special projects and it pleases most everyone. People who commit will save.

@ BigD
One single pre-pump is enough. Those will flow a lot of fuel. But it also works fine with the riginal late-model pressure pump. Just plumb a second one after the surge tank toward the fuel rail.

[BigD]

How much do the pre-pumps flow? What you did, Lee, is pretty much exactly what I plan to do. I'm not sure what to put into the sides of the tank though. It would be nice if I could just drop in two early pre-pumps. Otherwise, I was thinking of getting a pair of high volume, low pressure aftermarket pumps and installing them on the tank floor, as close to the outside as I can.

The engine will be using 65lb injectors with the A1000 pump for primary feed from the surge.

[BimmerTim]

If you did make a batch, I would likely buy one.

[Massive Lee]

EDIT: Actually, true r3vstyle would be to use aluminized muffler pipe, two caps, and some weld-on steel fittings.

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:

BTW Fred, you will be very happy with your external surge tank. Say farewell to fuel starvation. Our own e46 racecar can race on fuel fume. A motor burns between 0.5l (regular engine) and 1.0l (high po motor) of fuel per minute. So, as long as the pre-pump can feed that much fuel, you are golden. The benefit of the system is that the catch tank is fed by the pre-pump and the fuel return.

I made two dozen units last summer. I can make a batch if there's a demand.

[FredK]

Yep, the wiring is the same concept, the surge tank is another can of worms.

I think I might pull a r3v and just buy some pipe, make two end caps, and have someone weld it for me.

EDIT: Actually, true r3vstyle would be to use aluminized muffler pipe, two caps, and some weld-on steel fittings.

[BimmerTim]

Blunt and GoodnTight were just looking to feed more fuel to the motor for turboz, but the fuel pump wiring Fred was asking about is is the same concept.

[Massive Lee]

^^^^^

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.

[McGyver]

What Blunt and good n tight did was use the early model pump as a lifter or pre-pump for the 044. the 044 was wired in parallel to the original pump and located where the fuel filter is. then the fuel filter is placed in the engine bay along the inner fender. they both used the regular rubber fuel lines (high pressure from the 044 to the engine, and the stock 13mm line from the oem pump to the 044).