Fuel system questions

BAzombie

BAzombie

Well-Known Member
#1
#1
Ok guys I need some help for my winter build. I have about 90% of my build figured out. What I need help with is the fuel system.

I going to run a 5.3L block with a Logan intake and stage 3 N/A cams from MHS. I plan on turning 7k RPM and I'm hoping to see between 360 & 380 HP to the tires.

I'm thinking either 39# or 42# injectors. I would hate to go with 30#ers and be pushing the duty cycle on them. What I have no clue on is what I should use for a fuel pump.

Anyone have any suggestions ? :idk:
 
BAzombie

BAzombie

Well-Known Member
#3
#3
Thanks Rob, that would be Pete. :D

I don't know shit about fuel requirements. Just what I've read comparing fuel systems with HP output.


Only bad part of my plans is that I dying for winter to hurry up and get here. :smash:
 
FrostByte

FrostByte

Well-Known Member
#7
#7
BAzombie said:
Thanks Rob, that would be Pete. :D

I don't know shit about fuel requirements. Just what I've read comparing fuel systems with HP output.


Only bad part of my plans is that I dying for winter to hurry up and get here. :smash:
Click to expand...
DONT WISH YOUR LIFE AWAY FOR ANYTHING KID!!!!!;) Enjoy the summer, we never know how many we more we have. :D

 
modularmustang

modularmustang

Well-Known Member
#8
#8
you should be fine with 39# injectors, 30# would be pushing the limit on their duty cycle (93% assuming 380rwhp). You should Try to get as small of injector as you can so you can more easily tune at idle and low rpm.

You should be at about 85% duty cycle to be safe. So with stock fuel pressure of ~39psi you'll need ~33lb injectors.

a 255lph walbro should do the trick for you too

edit:
here is an injector sizing site i have saved in my favorites:
http://www.gtsparkplugs.com/InjectorSizeCalc.html
 
Last edited:
On Edge

On Edge

Well-Known Member
#9
#9
modularmustang said:
you should be fine with 39# injectors, 30# would be pushing the limit on their duty cycle (93% assuming 380rwhp). You should Try to get as small of injector as you can so you can more easily tune at idle and low rpm.

You should be at about 85% duty cycle to be safe. So with stock fuel pressure of ~39psi you'll need ~33lb injectors.

a 255lph walbro should do the trick for you too

edit:
here is an injector sizing site i have saved in my favorites:
Injector Size Calculator
Click to expand...

great info....just trying to understand...if you are trying to get as small of an injector....would this example use 33 lbers or 39 lbers. because you say you would need 33s, but 39s would be fine. so 39s arent too big? just wondering and learning. thanks.
 
J

joswo1980

Member
#10
#10
Go with 39# unless u can find some 42# green top lighting injectors with the 39#s ul need to also buy adapters but flow just as good as 42u, im running a division x stryker 340lp pump works great im at 83 duty cycle at at 416 rwhp on a boosted mustang, should be more than what u need for a all motor build
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On Edge

On Edge

Well-Known Member
#11
#11
joswo1980 said:
Go with 39# unless u can find some 42# green top lighting injectors with the 39#s ul need to also buy adapters but flow just as good as 42u, im running a division x stryker 340lp pump works great im at 83 duty cycle at at 416 rwhp on a boosted mustang, should be more than what u need for a all motor build

​
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how much was that division x stryker 340, and where do you buy them from ? thanks.
 
J

joswo1980

Member
#14
#14
The pprv is a delete u do in order to free up duty cycle cause its a major fuel restriction, all u gotta do is, when u pull ur housing out ul c 2 accordin style house and a small housing on top wit 2 tiny screws, ur gonna take them off and throw them right out, then ur gonna buy 1ft of gates 5/16 submerseable fuel line (no other lines will work, the gas will eat it ) ur gonna hook that hose straight from pump to ur fuel hat, makeing sure ot dosent kink, i used a brass elbow were it bends so i know it wont kink but u can also use a nylon elbow, but be4 that ur also gotta drill about 4-5 5/16 holes in bottom of basket
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J

joswo1980

Member
#15
#15
Yes its a direct fit just need to reuse ur old fuel pump sock or buy one like it, some ppl had to widen out top of basket were fuel pump comes up but i didnt have to
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On Edge

On Edge

Well-Known Member
#16
#16
joswo1980 said:
The pprv is a delete u do in order to free up duty cycle cause its a major fuel restriction, all u gotta do is, when u pull ur housing out ul c 2 accordin style house and a small housing on top wit 2 tiny screws, ur gonna take them off and throw them right out, then ur gonna buy 1ft of gates 5/16 submerseable fuel line (no other lines will work, the gas will eat it ) ur gonna hook that hose straight from pump to ur fuel hat, makeing sure ot dosent kink, i used a brass elbow were it bends so i know it wont kink but u can also use a nylon elbow, but be4 that ur also gotta drill about 4-5 5/16 holes in bottom of basket
​
Click to expand...
is the pprv delete for all 96-04"s....as the 99-o4 differ from earlier as the 99-04 have a returnless system ? its amazing how that acordian style hose can be such a fuel restrictor. but i know the hose your talking about. thanks.
 
J

joswo1980

Member
#19
#19
And ur not deleting just the hose, u need to delete whole system, the whole system in its self is a restriction, which is hoses and the little valve thing ontop of basket
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