Looking for help with my fuel system
12-01-2012, 05:59 PM
#1
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Looking for help with my fuel system I'm making 14-15 psi at 5500 shift points. On the efilive scans the duty cycle hit 98% to 104% at my shifts. I know I have enough injector for my set up and being a 1 bar maf tune my PE table has a lot lower values than it should. Also I know I'm pushing some air because the MAF is maxed at 4200!
My current set up is:
Bosch 044 in tank with wire kit,mototron 60's and the rest is a stock return style system.
I do not run a fuel pressure gauge but tuning the other day my duty cycles were climbing bad. I know the fuel pump isn't keeping up.
Options:
a boost a pump
second 044 in line on hobbs switch
different single pump that can outflow the 044
go back to a stock in tank an have the 044 in line
For right now I'm looking for ideas besides dual walbros in the tank.
My current set up is:
Bosch 044 in tank with wire kit,mototron 60's and the rest is a stock return style system.
I do not run a fuel pressure gauge but tuning the other day my duty cycles were climbing bad. I know the fuel pump isn't keeping up.
Options:
a boost a pump
second 044 in line on hobbs switch
different single pump that can outflow the 044
go back to a stock in tank an have the 044 in line
For right now I'm looking for ideas besides dual walbros in the tank.
12-03-2012, 02:22 PM
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you need a MAP referenced Fuel Pressure Regulator.
Do you already have one? Every pound of boost pushes back on the injector fuel pressure, hence decreasing your actual delivered fuel pressure, decreasing your fuel injector size. A MAP referenced FPR increases fuel pressure to match positive boost experienced, hence maintaining a solid #/hr rating.
It sounds & looks to me that you don't have a FPR... I looked through your signature
Do you already have one? Every pound of boost pushes back on the injector fuel pressure, hence decreasing your actual delivered fuel pressure, decreasing your fuel injector size. A MAP referenced FPR increases fuel pressure to match positive boost experienced, hence maintaining a solid #/hr rating.
It sounds & looks to me that you don't have a FPR... I looked through your signature
12-03-2012, 07:47 PM
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factory? what vehicle is this exactly? and why aren't you using a 2 bar or even 2.5 bar MAP & Tune?
255 Liter per hour pump supports 8 x 51.3 # injectors
300 Liter per hour pump supports 8 x 60# injectors (if I did my math right). And so here starts the kicker, if you actually do indeed have a Fuel pressure regulator that IS MAP referenced, at what pressure?
if your base pressure is 58psi, then I will go ahead and tell you your pump is maxed out. Reason being those 60# injectors are likely rated at 43.5psi and at 58psi they are 69.3# injectors...aka too much for that fuel pump.
58+15psi = 73psi, max of pump. I would suggest getting a 2nd pump and l think your injectors size is fine. what hp are you making?
even if your base pressure is 43.5psi, you are at the pumps max, as you are running 8 x 60lb injectors.
255 Liter per hour pump supports 8 x 51.3 # injectors
300 Liter per hour pump supports 8 x 60# injectors (if I did my math right). And so here starts the kicker, if you actually do indeed have a Fuel pressure regulator that IS MAP referenced, at what pressure?
if your base pressure is 58psi, then I will go ahead and tell you your pump is maxed out. Reason being those 60# injectors are likely rated at 43.5psi and at 58psi they are 69.3# injectors...aka too much for that fuel pump.
58+15psi = 73psi, max of pump. I would suggest getting a 2nd pump and l think your injectors size is fine. what hp are you making?
even if your base pressure is 43.5psi, you are at the pumps max, as you are running 8 x 60lb injectors.
12-03-2012, 08:14 PM
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The truck is in the pic. It's a 1999 silverado,which have a return style fuel system. The fpr is 1 to 1 and the base pressure 50 psi. As for the tune I've always used my PE table for fueling.
It's never been on a dyno but should be making around 600 rwhp based on track times and mph.
I might try a bap or different in tank pump.
It's never been on a dyno but should be making around 600 rwhp based on track times and mph.
I might try a bap or different in tank pump.