Which Fuel Injectors? 19,24,30...........

How do you know (besides trial & error) which fuel injectors to use on a 5.0? Thanks.

Derek

 

[Alec]

During my supercharger project, my mechanic and I did a bunch of math to figure out the right injectors and fuel pump. It can't hurt to go with larger injectors, but you may not need them. A rule of thumb I came up with for the 4.0 OHV is that you need larger than the stock 19# injectors with more than 8-9 # of continuous boost with the s/c. You do need to get a reprogrammed MAS when you change injectors. The MAS sensor is how you calibrate for larger injectors.

 

[Guy Groves]

I don't remember the exact number, but ...

19# injectors are good to about 270 - 300 HP.
24# injectors should cover you to for 350 - 380 HP

You can put the 24# injectors in a stock engine, but you are not using the injector as they were designed, so you will not get the same spray / atomization with 24# injectors in an engine that only makes 250 HP. Also remember the HP numbers we like to use only represent a portion of our driving. How often are you running at 5600 RPM making full HP? In most cases the 19# injectors should work out fine. Search for "mustang math" on the web and you will get some formulas you need to address this.

On the other hand if you put in an aggressive cam, aftermarket heads, do some porting, run a larger TB & MAF with headers. And you like to get on it ...
Go for the 24# injectors. You might also consider a Cobra ECC unit (fuel curves for 24# injectors)

 

[Sandy]

One thing to remember is that the 19# injectors can be driven harder by adding additional fuel pressure and work fine above 300 hp.

Just a thought !

I will be running a high lift, short duration roller cam in my SEFI 5.0 with 70mm Mass Air System, TrickFlow intake and heads, at approx 300+ hp.
I will be running 19# injectors because of the low speed trail riding I plan to do.
You need to consider your actual use before deciding on any modifications; BIGGER is not always better.

Good Luck,

 

[USAFEXPLORER]

Thanks for the help!