Fuel Pump Location

[mbuskuhl]

I added a fuel surge tank to my cell and decided why not do some other plumbing, the old combo of hard line/rubber line/braided line could be improved - rubber line out. With lots of AN fittings and hose in hand I went to work. Surge tank done, now I'm in the middle of relocating the pump to the top of the cell and am having second thoughts. The whole area is covered by an aluminum box as required but a search on the internet gives conflicting opinions on mounting a pump above the cell.

Is my setup going to....

be safe?

work fine?

...the pump will be easy to access now, that was the reason to move it. I have just the inlet and outlet hoses to run to the hard line and it's done, but no need to waste any more braided line if the pump isn't going to work where I got it. If you can't tell from the pic, the pumps a Bosch 044.

Car is a 2nd Gen RX7, exhaust exits on the right side of the picture so that's not a problem.

[rsportvolvo]

The Bosch '044' and other similar Bosch pumps are "pusher" pumps and do not survive very long in the "puller/lifter" configuration. You should use, at a minimum, an intank pre-pump to feed the your main fuel pump. Get a pre-pump from a Volvo 740 Turbo (cheap and readily available). I know of teams using them in Speed World Challenge and Australian V8 SuperCar.

David

[mbuskuhl]

Thanks for the information, I had read about pusher vs. lift pumps and couldn't find what the 044 was, guess that answers it. Weldon racing pumps gave me hope as theirs both lift and push.

I tried to find a picture of the Volvo pump you mentioned and it and all other in tank pumps looked like it would not fit in line to my surge tank. I didn't want to just set a pump in the surge tank but rather mount in line (-6 AN) to a bulkhead fitting that attaches to a pickup tube (fuel safe surge tank). I know the 044 can also be used internal but there's another $200 and if it's a pusher, I guess it's not an ideal solution.

If the 044 is mounted below the cell (can be done), would this fix my problem altogether? I guess this might create a siphon effect which would eliminate a "lifting" need.

[rsportvolvo]

The configuration I'm familiar with is having the lifter pumps feed a swirl pot/accumulator volume and the pusher pump feeding from that. As for the low mounted external pusher pump it should work fine. That is the same pump type and setup used on as stock Volvo 240. I will note that this setup had vapor lock issues in the heat and later Volvo 240 models and all later Volvo models used a lifter pump inside the fuel tank. Both of my BMW M3's use a lifter pump and an external low mounted pusher pump.

To cut the chase here give Bosch Motorsport a call and get their recommendation. They designed and built the pump and should be able to point you in the right direction.

[mbuskuhl]

David,

Thank you for the information. I wrote Bosch and this is what they had to say...Now to find the right pre-pump. I'll need to find the Volvo pump part # you recommend and check it's specs.

Hello Mark,

to grant the function of the 044 pump it should be mounted horizontally below the fuel level because the pump is not self-priming.
This kind of installation should be ok even without any kind of pre-pump.

If you would like to choose another location for the pump it will only work properly by using a pre-pump (e.g. in the fuel cell as you already mentioned).
Unfortunatey we do not have pre-pumps in our product-range that I might recommend to you.
If you are looking for a pre-pump you should ensure, that its fuel delivery is the same as of the 044 pump at minimum, better if it would be 5 - 10 % higher with a low fuel pressure.

Unfortunately I cannot offer a fitting pre-pump to you.


Regards,

Philipp

[markw]

In your picture it looks like you have an inline fuel filter. While I can appreciate a filter before the pump, that particular filter does not have much surface area. It could easily clog and burn out the fuel pump. I used an intank pump from a vw golf. The harness was a bear to do safely. If I were to do it over again, figuring my time, I like something like this. Intank fuel pump Fuel safe also makes a wiring harness. I use an external bosch pump after my external resevoir. The resevoir is filled by the intank pump and I return the bypass fuel back to the resevoir and finally back to the cell. Works great, but was a lot to do. Fuel safe's setup would accomplish all of this and save a a couple hundred dollars on steel braid and the time to install a wire harness for the intank. Just my take.

[Sandro]

I use one of these to suck the fuel out of the tank:

and then I have the stock pump that sends it to the CIS unit.

(this is on a CIS rabbit)

works great and cheaper than an in tank pump

[seckerich]

The number one cause for trouble in Rotary motors is screwing with a perfectly good fuel system. Stick with an intank pump in your cell and run the ATL black box. Buy the turbo pump and forget about it.

[racingralph]

if u feel the need to run with a feulcell , it would be best to mount the feul pump in the cell . or use the stock (89-91 18 1/2 gals) gas tank with tubo pump . it works great