Walbro Fuel Pumps and Flow vs HP data

[ButtonPuncher]

I've been doing some reserch 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.

[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:
http://www.stealth316.com/2-fuelpumpguide.htm#j5
http://www.roadraceengineering.com/f...pflowrates.htm


Source for fuel pumps:
http://autoperformanceengineering.com/html/fppumps.html
(I don't know about the Duratec, but the Zetec uses the GSS250, F20000141, GSS317, or the GSS342)


HTH,
BP

[warmonger]

You know, I read this post a while back and I meant to thank you for posting it. It won't help many people but it is really good information for those who need to size a pump and/or having pressure issues.

I feel bad looking at it and realizing no one even responded. All information is welcome, thanks.

[ButtonPuncher]

Anytime.


I have a tendancy of collecting all of this info and then just sticking it on my hard drive. This time I decided to post it for all.

I've got some good data on injector sizes too. I'll have to transfer that over from the old forums.

BP

[69Boss302]

On Friday I ordered a 255l/ph pump. mmm, what could this be for???

[ButtonPuncher]

About 510HP.

[DemonSVT]

190L/Hr pump is good for ~280HP

Incorrect.

The stock pump can support 300 wheels (~370 crank) under boost and it's not even 190l/hr. IIRC it's rated at 155 l/hr. Either that or Ford's wrong and it is really 210ish.

[ButtonPuncher]

I'm just telling you what I get when I crunch the numbers.

Most of the data in the "Maxium Boost" book is pretty conservative. I'm guessing this is too.

BP

[stealthy3L]

so a 3.0 with spray- 100 shot- thats around 340 to the crank.. should I be looking into a spec stage 3 clutch and a 190 or a 255 lph pump?

[warmonger]

Yeah, pretty close to that. I'd be looking at a clutch for sure and maybe a pump. I would dyno with it at 75 shot and then move up and see what happens before I changed out the pump.

[COUGAR99]

Thanks for the info ButtonPuncher.

When you did the numbers did you figure it out for a 4 cylinder or a 6? If you figured it out for a 4 that would explain why there is a deviation from what has been proven with the stock pump.