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Discussion Starter #1 (Edited)
Hi everyone,
I typed this up a while ago for the contour forums but I figured that I'd bring it over here for all to enjoy. If you are looking to go FI, or to a return style setup, this will help you choose the right sized pump.

If anyone knows the flow rate for our stock 6s pump, please speak up.

I've been doing some research and found some good info. Thought it would be nice to share it with all. :)

The three most common Walbro pumps are compared. The 190L/Hr, 255L/Hr, and the High Output 255L/Hr. They are tested at "stock" FPR of 43psi, "15psi of boost" or 58psi, and "30psi of boost" or 73psi.

Cross referencing the flow data with the chart in Corky Bell's book "Maximum Boost", we can obtain the following data:

190L/Hr pump is good for ~280HP
255L/Hr pump is good for ~510HP
255HP pump is good for ~610HP

All of the source links are at the bottom of this post. ;)

Code:
[Pump Model] [Battery Voltage] [Test Pressure] [Current Draw] [Flow]

Walbro "190" LPH GSS-250 12.5V 43psi 6.0amps 168.45 Ltr/Hr 
Walbro "190" LPH GSS-250 12.5V 58psi 7.0amps 145.11 Ltr/Hr
Walbro "190" LPH GSS-250 12.5V 73psi 8.0amps 88.96   Ltr/Hr  

Walbro "190" LPH GSS-250 14.0V 43psi 6.5amps 208.83 Ltr/Hr
Walbro "190" LPH GSS-250 14.0V 58psi 7.5amps 162.78 Ltr/Hr
Walbro "190" LPH GSS-250 14.0V 73psi 9.5amps 104.10 Ltr/Hr
  
    
Walbro "255" LPH GSS-317 12.5V 43psi 7.5amps 229.02 Ltr/Hr 
Walbro "255" LPH GSS-317 12.5V 58psi 9.0amps 201.89 Ltr/Hr 
Walbro "255" LPH GSS-317 12.5V 73psi 10.5amps 147.00 Ltr/Hr 

Walbro "255" LPH GSS-317 14.0V 43psi 8.0amps 261.83 Ltr/Hr 
Walbro "255" LPH GSS-317 14.0V 58psi 10amps 230.92 Ltr/Hr 
Walbro "255" LPH GSS-317 14.0V 73psi 11.5amps 182.97 Ltr/Hr 
  
 
Walbro "255 High Pressure" LPH GSS-342 12.5V 43psi 7amps 233.4 Ltr/Hr 
Walbro "255 High Pressure" LPH GSS-342 12.5V 58psi 9amps 210.10 Ltr/Hr 
Walbro "255 High Pressure" LPH GSS-342 12.5V 73psi 10.5amps 189.3 Ltr/Hr 

Walbro "255 High Pressure" LPH GSS-342 14.0V 43psi 8amps 264.4 Ltr/Hr 
Walbro "255 High Pressure" LPH GSS-342 14.0V 58psi 9.5amps 242.9 Ltr/Hr 
Walbro "255 High Pressure" LPH GSS-342 14.0V 73psi 11amps 220.8 Ltr/Hr
Check this graph out too just to see how much boosting the fuel pump's voltage can increase flow. This shows just how well a Boost-A-Pump can work.


Interesting note about using a stock FPR...

"Note, however, that using a 255 or 255HP pump on a DSM will probably require an adjustable aftermarket Fuel Pressure Regulator, especially if using larger injectors, in order to get the fuel pressure curve more linear. Any very high flow pump can overrun the tiny stock FPR, causing the base fuel pressure to be higher, and making the fuel curve nonlinear, making the ECU's control of the fuel more difficult. When coupled with larger injectors, you can basically flood the engine with fuel, causing your car to run super-rich (black smoke out the tailpipe almost all the time), lowering mpg and power. Installing an adj FPR allows you to dial the base fuel pressure back to stock, maintain a linear fuel pressure curve, and gain back mpg and power."


Links to source pages:
Stealth 316 - Fuel Pump Upgrade Guide
RRE Instructions


Source for fuel pumps:
Auto Performance Engineering - Walbro fuel pumps and more
(I don't know about the Duratec, but the Zetec uses the GSS250, F20000141, GSS317, or the GSS342)
Like I said in another thread, I'm planning on changing to a return style fuel system and a Walbro pump in the future. My '06 6s has a severe fuel starvation problem when below 1/4 tank.

BTW, I know that we don't have a FPR (fuel pressure regulator). Our cars use an adjustable voltage fuel pump to regulate the pressure. Pretty much standard on all '00 and up Fords/Mazdas.

HTH,
BP
 
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