im VERY familiar with the principle.

dont put words in my mouth. anyoen that read my posts can understand what i was talkign about.

flow and pressure are related. just as voltage and current are related.

but voltage is not current.

and pressure is NOT flow.

you seem to have tunnel vision. arguing with you is futile. doubleugly already proved that. Just let me know if you ever get a job with a major airline, i will be sure not to fly on those planes


this is the last time i am posting in this thread and distracting from the fact that AMS did soem great work ... and what is more impressive they actually made their findings public.

Cheers AMS

 

So familiar with it that you don't seem to even understand it. Pressure is DIRECTLY related to flow and vice versa. But as you said, arguing with you is futile since you seem to know more about something you don't work on. Nor have you provided any concise input into the conversation at hand. Just decided to pick a side...

Why did I single you out? Because you insisted on making assumptions about my job credibility, my integrity and my knowledge. Saying "I'm gonna go with *insert name*"....good job sheep, keep following the herder.

Feel free to not fly on ANY airline then. Gonna be racking up lots of miles on your cars.

 

i have to say that was a lot of stupid arguing over this basic statement.

i'll have to ask... what is the difference between running the pumps in parallel and running them into a y fitting? eventually both reach the fuel rail and much in the same way, delaying the hydraulic feedback doesn't do anything in a steadystate mode of operation.

 

great write up... good ol AMS FTW

 

I have been running my car this way for well over a year now.
Two external Walbro Pumps, -6 AN lines to and from the saddle - pumps- to fuel rail.
At the fuel rail I chose a -10 NOS Y adapter. It seemed to help with the transition a bit. With the -8 rail and fitting I actually noticed a spike in the VE table. Anyway Im not going to go crazy with specifics. I just wanted to add that the way the test results are charted on the first page of this thread, they make complete sense.
Great Job Martin.

 

Looks like Mythbusters. Nice work.

 

That is not totally accurate. The fuel pumps are positive displacement pumps. What goes in will go out. The pumps will discharge a specified amount with each revolution. The problem with running 2 pumps into a Y fitting is one pump will always be stronger than the other. When you run 2-255 pumps into a Y you do not get 510lph. You get some where around 408lph. These numbers are not perfectly accurate because there are other factors that affect the flow ie specific gravity of gasoline, I work with DFM F-76, size of the fuel lines and temperature also affects how gasoline flows. You are correct about the parrallel configuration or even just running a single larger pump.

 

update on the test. Here is some more data and I split it up to make it easier to read hopefully. I ran some Bosch 044 pumps which work really well (external pumps). I ran an STi pump but lost the data and will have to rerun it.

 

"Modified Walbro 255lph intank" = disabled pressure by-pass?

 

WOW!

Thank you AMS. This is a great test and seeing a vendor put effort into something like this and giving back to the community really means a lot. Definitely will make me think of AMS when buying parts down the road.

ps: Do you think you could test an in tank walbro 255 feeding an external Bosch 044? This is what I run and I'm curious about it's performance.

 

ams ftw :P
information like this is priceless :P

 

I second that request, this is what I've been planning on doing.

Thanks for your hard work and publicizing your results!

 

Are you running a walbro in tank directly to the Bosch 044? or via a swirl pot?

 

You seem to be implying that a Y-fitting is not the same as a parallel configuration... Is this correct? Can you please elaborate?

Interesting... anybody with fluid dynamics background care to chime in? Does the angle of convergence matter in this situation? If so, the method of evaluation of the parallel fuel pump tests might need to be re-examined.
AMS, can you please elaborate on your setup? It doesn't seem to be visible from the pictures...


The chart data seems to say that there is very minimal advantage to running anything in series... Pretty much anything in parallel blows anything in series out of the water.

 

Awesome tests guys! Thank you very much. Not sure it its plausible, but I am also curious as of the results with a 255 feeding a 044. The in-tank boost the inline 255 a good bit and I am assuming it would do the same for the Bosch unless it became the restriction. Any chance of trying to set this up?

Thanks again guys!