Ok guys I have a question about a walbro vs holley setup. The walbro is an EFI pump and pumps 255lph...Thats around 60gph or something like that but rated for 35+psi. Guys are running holley pumps that are 110gph at 15 or so psi. So the Holley pumps more fuel. Why is the Walbro superior to the Holley? According to what I have read, the Walbro runs at a 20% duty cycle and will outlive the Holley. I dont understand how they figure its low duty cycle when its running at full operation and the excess fuel is returned to the supply side of the pump to recirculate. How does the pump work at a lesser duty cycle?

 

https://www.dieseltruckresource.com/...d.php?t=152943

 

Saw that one the other day...I have a holley black pump layin around and so does stacked97. We are both thinking of installing them but I also have a walbro pump layin around I was just trying to figure out the math and understand how a Walbro runs at 20% duty cycle

 

ttt????

geez....... need more text

 

walbro pumps are rated for upto 130 psi max pressure.at 30 psi that is 40 percent duty cycle of what that pump can do. you can buy the bypass and adjust it up to 42 or down to 18 psi which keeps it cooler due to less pressure at 30 psi there is very little load on the pump so it does not have to work as hard that is where they say it will out last the other pump

 

I had a holly blue on my 2000 and I think the walbro is a much much better pump.

 

What are we using the pumps for? I have a holley blue and a walbro 255 from a mustang?

 

A lift pump to replace the stock pumps. For some of us the stock pumps cant keep up with the higher volumes of fuel.

 

LOL... these stock lift pumps are notorious for failing with low milage. Also under wide open throttle the pumps will drop to 0psi and almost starve the CP3 of fuel...so people are replacing the stock pumps to avoid hurting the motor and being stranded.

Walbro is the preffered method because they last forever on our trucks running at 30% duty cycle. They have higher pressure and pump plenty of fuel. Holley pumps are a cheap way to go as well. Some say they dont do as well because they are not rated for diesel...some people say they last forever. The blue pump pumps 110gph and the black 140gph. The walbro is a 255lph which is 60 something gph but they pump at a higher pressure (30+ comprared to holleys 10-20). Im confused some say that they are running 20psi with a holley pump and some are running 7-10.

Wade and I both have black pumps layin around so figured it was a cheap way though Walbro is preffered.

 

u can build a walbro system if you are good with fittings and hoses. im not that good with fuel systems. my walbro has worked good so far. I like it better than the fass pumps personally. the walbro is very quiet & dependable. I cant say that for the fass pumps im around.

 

ok..I think I understand what you are saying...but isnt the pump continously pumping at 100% capacity all the time? I think what you are saying, is that since the pump doesnt have a lot of head pressure, that its not trying to cram 10lbs of **** in a 5lb bag. Its still moving 10lbs of **** but the overflow flows back into the supply, relieving the pressure of the load. Hope that makes sense

 

The pump runs off the voltage that it is given. With the gdp kit a bypass is used so the pump is still running 100% but since it uses a bypass the pressure is only around 30 psi between the walbro and cp3. If the walbro was deadheaded then pressure between the walbro and cp3 would be like 130 psi. Since there is a bypass the walbo does not have to fight the 100 extra psi to get fuel where it needs to go. Rather it is only fighting 30 psi when its is rated at 130 psi there for the pump is only running at less then 30% of the pressure that it is rated for. Im sure thats about as clear as mud, 8mpg I hope that kinda answers your question.joel

 

yup.. I got it.. 10lbs of **** in a 5lb bag No I really do understand now. its the deadhead and head pressure that would cause the pump to work harder. Now where do I get a bypass valve? Thats the only thing really holding me up. I can get all the fittings and I just want to tap in the stock hardline right by the tank for the walbro. I dont want to run a hose clear up to the filter.

Thanks for clearing it up..its been messing with my head since yesterday

 

Call Richard at GDP, I found one at a local plumbing store, but its too big. I have 30 psi at idle but at wot with my boxes turned up I can pull pressure down to 0. So I finally ordered one from Richard, it should be here tomorrow along with my brothers kit. Its about $60 and you wont find it on the website. He only had like 2 or 3 extra so keep your fingers crossed. Joel