Fitting a Bosch 044 motorsport fuel pump in tank

Hey folks,

I've just finished fitting a Bosch 044 pump into my tank.
It was a massive amount of stuffing around and trial and error. Luckily I had a spare sender unit and a spare fuel tank to test with.

I went through quite a few different designs in the process. Some failed due to clearance issues like the pump bottoming out on the floor of the tank due to the size of the 044. Others were just from less that perfect welds by so called professionals causing leaks.

In the end I decided on a Speedflow -6 90 deg bulkhead fitting like this



Basically I stripped the cradle down and removed the float to avoid damaging it. This required de-soldering 2 wires.

I removed the stock check valve thingy which leaves a sort of platform like this.



I tried various ways of using this platform like welding -6 fitting directly to it. This made the pump too tall to fit in the tank so the platform has to come off.

I then had another fitting welded onto the base plate of the sender unit like this but this time the guy mig welded it when he should have tig'd it and it was leaking. Also as an added issue, the heat generated by the mig melted the brazing on the top side of the plate and caused a pin hole leak on the outside.



I could have fixed all this up but I just decided to go with the 90 deg fitting as it was going to be much less work than griding off yet another welded on fitting and having the pin hole sealed up. Plus having speedflow type fittings is just cool even if you can't see them!

So then I cut off the top pipe leaving something like this. I spent a bit of time getting it all nice and smooth on the top and bottom so the O-rings I mention later will seal



Because that whole pipe is brazed on when I drilled out the bottom part and then cut off the top part it made the hole in the plate larger than I wanted. Hard to explain but if you ever do this you'll understand what I mean.

I left it this way for now and used two washers that have an O-ring integrated into them and it seems to be sealing up quite well. I removed the o-ring that came with the fitting and used the two washer/o-rings one top and one bottom. I might go back and do it better by having a plate welded into the hole and then re-drilling it in the correct size, but for now I just need the car back together and it's not leaking at all so i'm happy.
I also used some thread locker/sealant stuff around the o-rings just in case.

So the end result on the top looks like this



And here is the pump secured for now. The fittings don't let it move very much anyway, But i wanted the extra support. I just flattened out the stock pump hangers for now. Might make up some better ones down the track but not really needed IMO. Also bear in mind that this pic shows a previous design with a weld on fitting at the base. This method worked, but was leaking as I mentioned earlier. If I had gotten a good weld it would have been fine.



I got the rubber pump sock from an auto parts shop, not off anything specific, just some old stock he had lying around. I just cut it to shape. Or you could just cut up the factory one.
I was trying to do whatever I could to minimise noise due to the 044's reputation, but because of space limitations like I mentioned previously I couldn't mount it like the stock pump is mounted with the small section of hose.
I had also considered running a surge tank and just using the 044 externally but the noise concerns turned me off that idea.

So in the end, yes it's louder that the stock one and I can hear it at idle even with my loud exhaust. But it's not too bad really, and once you are moving even a little bit you can't hear it anymore.
And i'd almost say that when priming it's actually a little quieter than what the stock one was.

Here is the section of line I made up in order to fit a Speedflow check valve. It sits in a cavity between the tank and the diff like this





You may ask why did I go to all this trouble, well I got an extremely good deal on the pump, and I didn't realise it was going to be such an ordeal haha.
Anyway, for anyone else that wants to try it, this should help a great deal.

One thing I did forget to mention is the filter sock in the pics is from a website called http://www.jayracing.com/



It was around $50 US, but they ripped me on delivery somewhat, and it ended up totalling around $110 AU delivered. I've seen a few other options around on the Supra forums and Skyline forums using socks from falcons and stuff that seem to do the job, but I was concerned that the pickup piping might be a bit small given the inlet size on the pump itself which is quite large.

Any questions don't hesitate to ask

Ben

 

awesome write up! whats it rated to?

 

Most specs say up to 700hp and 300 litres p/h.

The main reason I chose this pump, apart from the afore mentioned price, was that the bosch pumps have a much lower flow fall off as the pressure and heat rises. Walbro's for instance will flow much less than advertised as the pressure rises.

Ben

 

Will it accept the lower voltages (3 for TT and 2 for NA)?
Nice write-up BTW.
The oem TT fuel pump is supposed to be good til about 700 - 750 HP.

 

Everything i've read indicates that most aftermarket motorsport type fuel pumps don't like running low voltage. In fact it kills them.
Walbro's are notorious for this issue I gather and I think these are the same.
Another thing is the 044's are quite forgiving in regards to running your tank low and starving the pump. I've read that walbro's also don't like this at all.

It sounds like i'm bashing walbro's alot here but that's not the case, only using them as an example as to why I went the way I did.
I just added up all the evidence, stories and opinions from lots of different sources and made my choice. In hind sight, ease of fitment should have played a bigger part and a walbro (or probably two) would have been a pretty decent choice.

So the one thing I forgot to show was how I wired up the 044. It was made much easier by the fact that my battery is in the back, so just added some nice thick wire and a relay, and then ran a trigger wire direct from my Microtech ECU.
I also disconnected the FPCU and i'll probably remove it at some stage. Weight reduction yo!

Running from a stock ECU would be a similar process. You might get away with just bypassing the FPCU, but I would run new bigger wires straight to the battery anyway just to be sure. Why take the risk.

Ben

PS, yeah I understand the stock pump is quite good. I wasen't sure that there was anything wrong with my old pump but i'd upgraded everything else in the fuel system and that was the last thing to do.

Just looking at the physical size difference between the two pumps means the the bosch must be better right? hehe

Thousands of people with massive horsepower cars around the world can't be wrong.

 

haha bashing my walbro pump! I got rid of my FPCU when i installed my walbro. i cant imagine the noise that pump would make is it loud??

 

It's slightly louder at idle than my previous pump which I believe was a stock one.
But having said that I noticed that the stock pump got alot louder when I switched to the Microtech. I don't recall hearing it very much if at all with the stock ECU, but after the switch you could definatly hear it priming and a bit at idle.

With the current pump, like I said once you start moving even a little bit you can't really hear it anymore.

Ben

 

Nice work dude, But wouldnt it have just been easier to get a new OEM pump that slotted straight in.

It has a higher flow rate than the Bosch.

 

supra boys have been doing this for a while..

the real benefit of a bosch is when its feeding from a surge tank... hence you will never get fuel starvation on long corners or if u park on a really steep hill !

 

Different places rate it between 200lph and 300lph.
The reason being this.

It's 200lph @ 5 Bar (72.5psi) and 300lph @ 2 bar (29psi)

So at my maximum fuel pressure of around 60psi (4.1 bar) the bosch is doing around 234 lph. Calculated by me, and not entirely accurate since i'm pretty sure the flow fall off is not linear.

Where as the walbro for example is only flowing 189lph at 60psi. (according to some charts I found.

I can't find any hard data on the OEM pump, but yes I understand it's a good peice of kit. However I would be very interested to see some detailed flow Vs pressure rates on it.

There's so much conflicting information around on flow rates and pressures at different voltages, using different forms of measurement. It's hard to take it all in get something solid out of it.

Basically i've got a few friends in the drag racing community and the 044 came highly recommended. It's done now anyway so i'm going to see how it goes. Should be going on the dyno thurs in preperation for friday at Oran park, so we'll see how it holds up.

Cheers
Ben

 

There was testing done by JP about a year ago on a number of pumps.

I can vaguely remember that the new OEM pump came up the best in his tests.

But I do seem to remember they where free flow tests not 40 PSI tests.

 

overkill in this case is not a bad thing at all (for any fuel system)! top writeup by the way!

 

This is about the most comprehensive page I have seen on different pumps. Sadly the 044 isnt in there.

http://www.stealth316.com/2-fuelpumpguide.htm