Sorry 60lb inj question

[87GN_70GS]

that's true if the injectors are being held a constant duty cycle and acting as a restriction. In this case, the reason for fuel pressure loss is because the injectors are opening more and more, opening for so much time that they become less of a restriction in the system. Less restriction = more flow.

from a system point of view, as the injectors open more and more then fuel flow will continue to increase until the fuel pressure is very close to the boost pressure.

Just like a garden hose with a nozzle...

If you only consider the pump and nothing else, fuel pump flow drops off with increasing fuel pump outlet pressure.

If you only consider the injectors and nothing else, injector fuel flow increases with increasing injector inlet pressure.

That's why the curves look they way they do on the chart; pump curves go down and to the right, injector curves go up and to the right.

Maybe I should have been more clear in my original answer.

For a total system solution, you will need a flow bench test setup with all the components or a chart like the one given.

 

[87GN_70GS]

Ok guys after reading on fuel pumps I think IM going to get the 80s run my my in tank W340 for now and see how it goes. If the 340 dosnt keep up if I have read correctly I can add an external pump after the internal pump this should be a lot cheaper and easier then droping my tank to add a in tank dubble pumper set up. If I do need an external pump what would be a good one to use?

Yes, you can add an external in-line. For 80's, the W340/0169 + Bosch 044/413 should be sufficient. For even bigger, W340/0169 + the Pierburg SL55 AMG should do it.

 

[87GN_70GS]

87gn 70gs, You may have answered this before, are 80's at 100% dc are too much for a bosch 044? What about 80's at 100% dc and a walbro 340 + bosch044?

Yes, according to the info I have, 80#'s are too much for a single 044/413; it's only good for 65#'s by itself. But the W340/0169 + Bosch 044/413 should be good up to 83#'s inj.

 

[The_Six]

Would an in line Walbro be enough with the Walbro 340 I have now. Just wondering since there only $130?

 

[BEATAV8]

If you only consider the pump and nothing else, fuel pump flow drops off with increasing fuel pump outlet pressure.

If you only consider the injectors and nothing else, injector fuel flow increases with increasing injector inlet pressure.

That's why the curves look they way they do on the chart; pump curves go down and to the right, injector curves go up and to the right.

Maybe I should have been more clear in my original answer.

For a total system solution, you will need a flow bench test setup with all the components or a chart like the one given.

We're on the same page.

The point I'm interested in is just that fuel system isn't really maxed out when the fuel pressure drops off due to big injectors. The system is not operating at "rated conditions" anymore, but it can continue to increase the fuel rate as the injector pulsewidth increases.

 

[RobS]

Would an in line Walbro be enough with the Walbro 340 I have now. Just wondering since there only $130?

Make sure the second pump is the same output or greater. It appears a GSL392 is a high pressure 255lph inline pump.

 

[49-blues]

How would a in line pump be wired in the system if keeping the in tank pump?would you tap into the existing wiring? Considering adding a secondary in line pump also for E-85.

 

[87GN_70GS]

How would a in line pump be wired in the system if keeping the in tank pump?would you tap into the existing wiring? Considering adding a secondary in line pump also for E-85.

I wouldn't. You're basically doubling (or maybe more with a bigger inline pump) the current the wiring is trying to handle. I would recommend a separate electrical feed.

 

[87GN_70GS]

We're on the same page.

The point I'm interested in is just that fuel system isn't really maxed out when the fuel pressure drops off due to big injectors. The system is not operating at "rated conditions" anymore, but it can continue to increase the fuel rate as the injector pulsewidth increases.

Yes, agreed. If you are at the limit of a pump (pump and inj curves have intersected), and you are able to increase pulsewidth or dc% any (same as moving to a bigger inj curve), then although the rail pressure will drop, total fuel flow will increase (operating point will move up and to the left). This is not ideal, but dropping base fuel pressure and retuning for low dc% conditions will get you back linear fuel delivery across the boost/dc range.

 

[87GN_70GS]

Would an in line Walbro be enough with the Walbro 340 I have now. Just wondering since there only $130?

No, I just did the math on a W340/0169 in series with a W GSL392 and it's not enough to support 80's. You're gonna need a Bosch 044, $185 at amazon.com.

 

[RobS]

How would a in line pump be wired in the system if keeping the in tank pump?would you tap into the existing wiring? Considering adding a secondary in line pump also for E-85.

I was thinking of running a 2nd hotwire kit to the external pump. Then making some sort of ground wire myself. I would use the fuel pump prime wire to close the relay just like the 1st hotwire kit.

 

[The_Six]

Thanks guys, for wiring I was going to use a rectronix universal hot wire kit and use my trans pro not a hobs to turn it off and on.

 

[RobS]

Thanks guys, for wiring I was going to use a rectronix universal hot wire kit and use my trans pro not a hobs to turn it off and on.

I'm not sure but I don't think you would get much flow if both pumps were not running at the same time. I think the 2nd pump would be a huge restriction on the 1st. If they were wired to run all the time, it may make too much pressure. I posted the question of running 2 pumps in series.

http://www.turbobuick.com/forums/e85-technical-forum/322234-anyone-running-2-fuel-pumps-series.html

 

[RobS]

http://www.turbobuick.com/forums/e85-technical-forum/308547-i-only-want-buy-injectors-once.html



Around post 34 the op installed an areomotive pump and bosch on series. Please read.

 

[The_Six]

Im going to have to go read some more I was going to do a DIY in tank but then seen some guys are running them in series so I thought this would be the better way to go I may just go back to an in tank duble pumper.

 

[RobS]

Im going to have to go read some more I was going to do a DIY in tank but then seen some guys are running them in series so I thought this would be the better way to go I may just go back to an in tank duble pumper.

I wanted to do the same. I believe if you put one pump after the other:
1 you have to run both at the same time.

2 the intank pump must be smaller than the 2nd (downstream pump).

Maybe 87gn could verify this, when you run pumps in series it boosts head(psi) when you run them in parallel it boosts volume(flow). 2 pumps in series could be too much pressure for the pressure regulator to handle at idle thats why I wanted some feedback to see if anyone has done this.

 

[87GN_70GS]

I wanted to do the same. I believe if you put one pump after the other:
1 you have to run both at the same time.

2 the intank pump must be smaller than the 2nd (downstream pump).

Maybe 87gn could verify this, when you run pumps in series it boosts head(psi) when you run them in parallel it boosts volume(flow). 2 pumps in series could be too much pressure for the pressure regulator to handle at idle thats why I wanted some feedback to see if anyone has done this.

Yes, you want the smaller pump ahead of the bigger pump.

Yes, two pumps in series will boost head pressure (you add head pressures from each individual pump at any given flow rate on a chart to get total flow/pressure).

Yes, two pumps in parallel will boost flow rate (you add flow rate from each individual pump at any given pressure on a chart to get total flow/pressure).

Actually its the pumps in parallel case that will easily overwhelm the regulator as it is the flow rate that causes the problem; the regulator/return lines are only so big and excess flow rate will cause unwanted pressure rise (due to the fixed sized restrictions).

 

[The_Six]

Ok so If I put the 044 in line and leave the 340 in the tank do I need to run the 044 or the 340 all the time ?

 

[87GN_70GS]

Ok so If I put the 044 in line and leave the 340 in the tank do I need to run the 044 or the 340 all the time ?

Yes (because they are both positive displacement pumps)

 

[GNWANTED]

Hit my first 11 this weekend 11.94 with 60's & e85. Car ran good all weekend and did not see any knock. Duty cycle was around 95-98% but never hit 100% I will post a PL later tonight if I can.
This was the first time at the track with e85