Board logo

Fuel pump recommendations
CTLeeds - 11/1/19 at 06:34 PM

Hi guys, I'm looking for some advice/recommendations regards choice of fuel pump for my 2.8 BMW N/A engined Dax Rush. I took it for a session on the rolling road to get a custom map done and after the first run the tuning guy said the fuel pump was no good. We tested it using an inline fuel pressure gauge and he was right. After about 4800RPM the fuel pressure dropped right off, it couldn't keep up with demand. It's my own fault for buying a cheap Bosch 044 "equivalent" to start with. Anyway second time round I'd like to get the right pump that will be able to keep up. The only reason I don't just get a 044 is that it strikes me as overkill?

The BMW fuel rail has a 3.5 bar regulator.

Any thoughts/advice appreciated. I find the whole supply volume v pressure thing a bit complicated tbh!

Thanks


Chris

gremlin1234 - 11/1/19 at 07:14 PM

it the pump 'in the tank?'

the 044 pumps require 'flood fill' sometimes this is accomplished with a feed pump, but better if it can the immersed in the fuel

CTLeeds - 11/1/19 at 08:02 PM

It's an external inline pump that I'm after.

Thanks

Chris

daviep - 11/1/19 at 09:04 PM

Do you have any filters inline?

Is the pump noisy or hot?

How many HP do you expect to make?

In what sense do you think the 044 pump is overkill, why not just buy a genuine 044?

CTLeeds - 11/1/19 at 09:13 PM

quote:
Originally posted by daviep
Do you have any filters inline?

Is the pump noisy or hot?

How many HP do you expect to make?

In what sense do you think the 044 pump is overkill, why not just buy a genuine 044?


I have a pre-pump filter inline, the pump is pretty noisy and is drawing a lot of current. Straight out of the box it was drawing in excess of 20 amps at 12.5v. I had to replace the original 20 amp fuse with a 25 to stop it blowing.

I'm not expecting big horsepower, maybe just north of 200bhp.

The 044 is designed for cars up to 500bhp, as I'm not getting anywhere near that should I go for something smaller, maybe a Bosch 070?

BaileyPerformance - 12/1/19 at 10:38 AM

unless bloody massive you should not use a pre filter, only a filter after the pump

Use a genuine Bosch pump, STD cosworth would be fine

CTLeeds - 12/1/19 at 10:48 AM

quote:
Originally posted by BaileyPerformance
unless bloody massive you should not use a pre filter, only a filter after the pump

Use a genuine Bosch pump, STD cosworth would be fine


All pump manufacturers suggest a pre pump filter to prevent any crap in the tank entering the pump, is this not the case? I understand it will impede flow...

Do you know the part number for the cosworth pump?

Thanks

Chris

BaileyPerformance - 12/1/19 at 12:16 PM

quote:
Originally posted by CTLeeds
quote:
Originally posted by BaileyPerformance
unless bloody massive you should not use a pre filter, only a filter after the pump

Use a genuine Bosch pump, STD cosworth would be fine


All pump manufacturers suggest a pre pump filter to prevent any crap in the tank entering the pump, is this not the case? I understand it will impede flow...

Do you know the part number for the cosworth pump?

Thanks

Chris


All 1990s fords (cosworth etc) DO NOT have a pre filter, the pump MUST be under the tank, 12mm bore feed pipe as short as poss

britishtrident - 13/1/19 at 07:54 PM

Any filter before the pump has to be just screen filter --- ie huge area and just a small enough mesh to keep the rocks out. Any restriction on the suction side of the pump will result in cavitation boiling in the pump.

Oddified - 15/1/19 at 09:36 PM

Remove the prefilter, if the pump suddenly goes noticeably quieter it was cavitating which would mean it wouldn't be supplying the flow/pressure expected (it also severely shortens the life of the pump).

Ian