How can I fit dual Fuel Pumps?

[BMWTurbo]

Hi Guys,

I was hoping that someone in here might be able to help me out with a solution to a problem I'm trying to resolve.

I have an early model E30, with the 'intank' fuel pump on the hanger. I've fitted a little TRE-340 pump, but have since decided this will not be large enough. I need to be able to supply 9-10L/min of fuel to my swirl pot. A pair of TRE's should just make the grade, but the problem I have is fitting both of these into the tank. The opening for the pump/gauge is only large enough to squeeze one pump through.

I'm hoping there is possibly a dual pump tank similar to the E36's that I might be able to source to achieve this.

I do have the potential to use the std E30 non-intank pick-up, but I'm not comfortable the tank won't surge and don't want to risk an engine to it.

Sorry for the lengthy read, but hoping some of the knowledgable members here may be able to point me in the right direction.

Cheers
Ben

[lennon]

I'm a little confused about what you're asking. Are you talking about two high pressure pumps? Either way...

There's two spots in the late model 325i tank (88+). One on the passenger side with the pump (high pressure, single pump on these e30s, not 1 transfer and 1 high pressure), and another spot like it on the driver's side of the tank for the 2nd fuel tank level sender.

Read this if you want:

http://www.r3vlimited.com/board/showthread.php?t=157887

[jlevie]

Two low pressure transfer pumps feeding a swirl pot that feeds an external high pressure pump is probably the best solution. But the solution I used (in the thread mentioned) also works.

[BMWTurbo]

Thanks guys. Perfect.

I'll duck on Real OEM and see if there were available in Australia and try and source a suitable tank locally.

jlevie:- you have described what I'm planning to run, I don't know of any low pressure pumps that will outflow a TRE-340 style pump though? I'm open to suggestions on pumps that can flow 80-100GPH into low pressures, are submersible, fairly quiet and have a low current draw.

[jlevie]

I think a pair of OE transfer pumps might produce flow in that range. The spec for a transfer pump is in the Bentley manual.

[BMWTurbo]

I think a pair of OE transfer pumps might produce flow in that range. The spec for a transfer pump is in the Bentley manual.

Cheers.. I doubt the factory pumps will flow anywhere near that TBH. I flowed tested a factory intank E32 BOSCH pump a while back and it was dismal at best :P I replaced it with a Walbro at that time and the Walbro flowed 4 times as much fuel as the BOSCH.

Having said that I will have a pair of factory E30 pumps by the time I've sourced the tank so can test thier flow, but doubt I'd be comfortable using something that old in the system.

[jlevie]

There are two kinds of in-tank pumps. One is a high pressure pump and the other is a low pressure transfer pump. The high pressure pump has a much lower flow rate than the transfer pump. The transfer pump is used on early E30's that have the two pump system. The in-tank high pressure pump is used on later (from 9/87) E30's and most other BMW models.

For what you are contemplating you want to use two transfer pumps to feed a four port swirl tank and feed an external high pressure pump from the swirl tank.

[BMWTurbo]

Thanks jlevie,

Do you have any information re low pressure flow for these pumps? As mentioned I need something that can flow around 5-6L/min each.
Can they be bought new for a reasonable price anywhere?