4.0l 24lb Injectors

[Manscout]

I am looking to replace my stock injectors with 24lb ones. I believe this will help me get over 3k RPM with the supercharger. I currently top out at 3k under load.
Can anyone supply me with the correct injectors, or point me in the right direction?

 

[SenorNoob]

I have a local copy of this: Stan Weiss' - Electronic Fuel Injector (EFI) Flow Data Table.

I'm sure there is a part number in there somewhere.

 

[bobbywalter]

i assume you have an adjustable fuel pressure regulator? with a power adder a good regulator and wideband setup are wise investment items



you have 24 pound injectors if you are running 42 pounds fuel psi wot.

so...probably look at 30s.

or just adapt and run some ls injectors.

i suspect your 3 k issue is something else.


if you do not have an adjustable fuel pressure regulator....get one and play with the psi a bit to see if it helps....step right up to 55 and if it steps up then injectors are likely a good idea. of course it will blow ya out at idle but you can figure out what ya need.

 

[Manscout]

I have a local copy of this: Stan Weiss' - Electronic Fuel Injector (EFI) Flow Data Table.

I'm sure there is a part number in there somewhere.

Thanks! This was an excellent resource to start with.

 

[Manscout]

i assume you have an adjustable fuel pressure regulator? with a power adder a good regulator and wideband setup are wise investment items



you have 24 pound injectors if you are running 42 pounds fuel psi wot.

so...probably look at 30s.

or just adapt and run some ls injectors.

i suspect your 3 k issue is something else.


if you do not have an adjustable fuel pressure regulator....get one and play with the psi a bit to see if it helps....step right up to 55 and if it steps up then injectors are likely a good idea. of course it will blow ya out at idle but you can figure out what ya need.

I do not have an adjustable regulator. I went from the info on TRS and Tom Morana. They mentioned higher PSI injectors, but I didn't see anything about regulators.
I built it with a small pulley to build boost at lower RPM. I suspect the 3k issue is the injectors are being overwhelmed by the time it hits that engine speed. Before the supercharger, I always tried to keep it below 3,000 RPM, but I could go higher if I wanted.
I appreciate the tips!

 

[Manscout]

After doing a lot of research, I found that I do indeed need at least 24lb.
Summit has this handy chart and calculation I used. https://help.summitracing.com/knowledgebase/article/SR-04807/en-us

Based on this: I estimate I have around 200HP. I used .6 for my BSFC (200 X 0.6) ÷ (6 X 0.8) = 25 lbs./hr.

 

[bobbywalter]

reread my post ..

After doing a lot of research, I found that I do indeed need at least 24lb.
Summit has this handy chart and calculation I used. https://help.summitracing.com/knowledgebase/article/SR-04807/en-us

Based on this: I estimate I have around 200HP. I used .6 for my BSFC (200 X 0.6) ÷ (6 X 0.8) = 25 lbs./hr.

i suspect a different issue with it kicking out at 3k.

 

[gaz]

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@Manscout
If I remember correctly the Ford H.O. 5.0l used 24lb injectors, plug n play.

 

[snoranger]

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@Manscout
If I remember correctly the Ford H.O. 5.0l used 24lb injectors, plug n play.

No. The standard 5.0L HO only used 19LB injectors. The 5.0 Cobra motors used 24 LB EV1 injectors, as the the 4.6 Cobra up to 98.

 

[bobbywalter]

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@Manscout
If I remember correctly the Ford H.O. 5.0l used 24lb injectors, plug n play.

v6 needs bigger injectors for a given power level...sub 190 hp v8 tend to use smaller then 19#.... ho used 19# and cobra 24#.

we always used red top 4.0 injectors for our 5.0 to get 24# injectors for next to nothing or nothing and cranked psi a bit over 300 HP