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2 Bosch 044 Fuel Pumps

Marko R1

By Marko R1,
in Engines & Forced Induction

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Marko R1 Grand Master

Marko R1

Posted
Posted

hi guys,

i have 2 bosch 044 fuel pumps setup external with a surge tank.

both of my fuel lines which run to the fuel rail are 8mm I.D, my question is what I.D. should i use for my return line as ive fitted 6.5mm & not sure if this is ok?

regards,

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https://www.sau.com.au/forums/topic/274774-2-bosch-044-fuel-pumps/
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Adriano Grand Master

Adriano

Posted
Posted

I would run a least a 3/8(10mm) internal diameter return line. What reg are you going to use. There was a guy on here last week with the same setup, and had issues controlling fuel pressure. I hope you are running 1200cc injectors to make use of the overkill fuel system. I think you will definately need a fuel cooler as well.

STATUS Grand Master

STATUS

Posted
Posted

i cant remmeber your setup but you could use the std feed as the return. What is your expected power goal?

Im feeling your pain cause we are currentley setting up a fuel system in a soarer (still using std tank, but modified internally) for 1500hp (-10 feed -8 return) and it is a nightmare running that size line :thumbsup:

R31Nismoid Grand Master

R31Nismoid

Posted
Posted
That fuel system is massively overkill - thats enough fuel flow and injector for 700rwkw using BSFC of about 0.55 (Which should be close enough for pump fuel)!!!

Thats a safety factory of about %75.

Agreed.

When you see countless GTR's running 380rwkw with nothing more than a replacement intank pump and 700-800cc injectors and the STOCK fuel rail/lines etc etc...

You gotta step back for a second and think seriously about where to draw the line in the sand with regards to going 'too safe' :)

Marko we've ALL told you 800cc injectors is more than enough, why are you going 1000cc?

Im all for safety of a big $$ motor, but like i said above, you've gotta draw a line somewhere... I suppose if your line is a fuel setup for 600rwkw then fair enough...

unique1 Mentor

unique1

Posted
Posted (edited)

so what do u suggest for 450rwkw then? a single 044 is not gonna cut it, so the cheapest option is to use 2 of them simple. Injector wise if your gonna buy some then why not go the 1000cc's? it just means you never have to upgrade anything again :)

I run twin 044's and use a 1/2' feed and 3/8' return with no dramas. Also running 1000cc injectors as well.

Edited by unique1
R31Nismoid Grand Master

R31Nismoid

Posted
Posted

^ He isn't.

so what do u suggest for 450rwkw then? a single 044 is not gonna cut it, so the cheapest option is to use 2 of them simple. Injector wise if your gonna buy some then why not go the 1000cc's? it just means you never have to upgrade anything again :)

I run twin 044's and use a 1/2' feed and 3/8' return with no dramas. Also running 1000cc injectors as well.

If you set an aim, budget etc, then there is no reason to allow for headroom.

I believe in buying/fitting the correct parts rather than planning for something that might/might not happen in the future.

And what happens if one of the fuel pumps die? :(

You could always use a 800hp fuel pump for 450rwkw... plenty of them on the market if you actually look ;)

But that's not the question being asked.

Marko R1 Grand Master

Marko R1

Posted
  • Author
Posted

i am using 98 for run in then going to e85 'IF' my tuner to use it - that is why i went with 1000cc

my tuner also recommeded i go with 2 044's & others such as dirtgarage :)

all it takes is a split second of running lean & pop goes the weasel!

i upgraded my return line - all done :cool:

skylinekid Proficient

skylinekid

Posted
Posted (edited)
I would run a least a 3/8(10mm) internal diameter return line. What reg are you going to use. There was a guy on here last week with the same setup, and had issues controlling fuel pressure. I hope you are running 1200cc injectors to make use of the overkill fuel system. I think you will definately need a fuel cooler as well.

yeh ur right there was but not nemore.... with the engine running i can switch on the 2nd pump and the noise isnt there nemore... needle on gauge doesnt jump or kick work perfect now and the turbosmart fpr1200 is working great... yes i did end up running that 2nd 1/2" feed now its overkill but its there so i dont really care.... and yeh im gonna be hitting around 450+rwkw and im only running 800cc injectors. should be fine i guess. see how we go.

oh and yeh a 3/8 return will be fine... tis wat ive got and works fine..

Edited by skylinekid
R31Nismoid Grand Master

R31Nismoid

Posted
Posted
i am using 98 for run in then going to e85 'IF' my tuner to use it - that is why i went with 1000cc

my tuner also recommeded i go with 2 044's & others such as dirtgarage :)

all it takes is a split second of running lean & pop goes the weasel!

i upgraded my return line - all done :cool:

I hope you setup the dual pumps correctly, one failing will lead to a motor death if incorrectly setup.

Hence dual is not neccesarily the best solution over a single.

With a single, pump dies, car stalls

With a dual, pump dies, car still runs - lean as shit - BOOM

Sydneykid Grand Master

Sydneykid

Posted
Posted

The attraction of E85 is hard to fight, hence why I am using 2 x 044's and 1000 cc injectors in the RB31DET. The reality was the 1000 cc Rochester injectors didn't cost any more than the 800 cc's, so there was no reason not to go for the 1000's. The Power FC runs them easily, so no overfueling/tuning excuse. As for 2 x 044's, well one of them wouldn't quite flow enough and I have 2 sets of lines (the old HICAS ones) and a duel feed fuel rail and surge tank. So adding a second pump was logical and very simple to execute. Again, cost was relevant, and buying an extra 044 is not such a big burden.

I have fuel pressure warning on the dash, so if one pump fails, I will know about it instantly. Not that I have ever had a genuine Bosch fuel pump fail without lots of warning. They always make heaps of noise before there is any effective loss of flow or pressure.

In the 1 pump versus 2 pumps arguments there are good and bad points both ways. My experience has been that there are 2 route causes for fuel pump failure;

Electrical, where the electric motor driving the pump fails. This is very rare in fuel pumps and results in zero flow, instantly the electric motor stops turning. I have never seen a Bosch fuel pump ever do this. In the unlikely event where there is sudden failure like this, then one pump is an advantage over 2 pumps.

Mechanical, where the pump itself fails, usually do to wear and tear of the rotating components. Which is why you can hear the noise, long befiore the pump stops pumping. This is more common than electric motor failure, but that's not to say its common. There is also the damage scenario where debris sucked into the pump causes premature wear, this is usually caused by poor fuel quality and/or damage screens on the pick up. In the event of this type of gradual fuel pump failure, then 2 pumps with high redundancy are undoubtably better than one pump. If you have wear in a single pump installation then flow and pressure will suffer long before the same scenario is a problem in a 2 pump installation. And you will hear the noise in next idling phase and can take remedial action.

It has been my experience that most lean out scenarios are not caused by the fuel pump/pumps themsleves, it is usually an installation problem. Either with the electronics, wiring, relays etc or the plumbing. So having one pump or two won't help you if your installation isn't up to it.

Whatever fuel system you run, IMHO it is never a good idea to run any high powered car without a fuel pressure gauge/monitor. Even the R33GTST at 450 bhp runs a GReddy fuel pressure gauge with warning light, after all $200 is small price to pay to save a $10K engine.

Cheers

Gary

Marko R1 Grand Master

Marko R1

Posted
  • Author
Posted
The attraction of E85 is hard to fight, hence why I am using 2 x 044's and 1000 cc injectors in the RB31DET. The reality was the 1000 cc Rochester injectors didn't cost any more than the 800 cc's, so there was no reason not to go for the 1000's. The Power FC runs them easily, so no overfueling/tuning excuse. As for 2 x 044's, well one of them wouldn't quite flow enough and I have 2 sets of lines (the old HICAS ones) and a duel feed fuel rail and surge tank. So adding a second pump was logical and very simple to execute. Again, cost was relevant, and buying an extra 044 is not such a big burden.

I have fuel pressure warning on the dash, so if one pump fails, I will know about it instantly. Not that I have ever had a genuine Bosch fuel pump fail without lots of warning. They always make heaps of noise before there is any effective loss of flow or pressure.

IMHO it is never a good idea to run any high powered car without a fuel pressure gauge/monitor. Even the R33GTST at 450 bhp runs a GReddy fuel pressure gauge with warning light, after all $200 is small price to pay to save a $10K engine.

Cheers

Gary

my setup is similar to yours i.e. power fc, 2 044's, surge tank & rochester 1000cc injectors

who does your tuning gary? if u prefer send me a pm

regards

marko

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