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Larger Injectors Duel-Port EJ22: Ideas?


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I could write a long technical answer to this but I'm not sure anyone would care. The short answer is no without other modifications to the engine, intake, stand alone fuel management, and or exhaust. Think of the engine as a pump. The more air you can move through it with modifications (cam, intake, exhaust, turbo, etc) the more fuel will be required to keep the mixture in the proper range. A/F ratio for that engine is probably somewhere on the order of 14.7:1 you can run slightly fatter than that, anything else is just a waste of fuel in my opinion.

 

Another option instead of increasing injector size is upping the fuel system pressure. Most injectors only run at about 60% duty cycle, so there is some room to fatten the system up with what you already have.

Edited by Crazyeights
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Good to know, yeah I was figuring it would be over fueled in a sense if has stock cams and engine management.

 

I wonder, if you increase the Fuel PSI, would that mess up any fuel regulator?

 

Thanks for the answer!

 

-Tom

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To increase the fuel pressure would require a different regulator, or some sort of modification to the current fuel system. First check the system's fuel pressure as stock and then the maximum pressure the pump is capable of. You don't want to run the fuel pump at over about 80% of it's rating or the injectors over 90% of their duty cycle or they will overheat over a long period of time.

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To increase the fuel pressure would require a different regulator, or some sort of modification to the current fuel system. First check the system's fuel pressure as stock and then the maximum pressure the pump is capable of. You don't want to run the fuel pump at over about 80% of it's rating or the injectors over 90% of their duty cycle or they will overheat over a long period of time.

 

 

From what I remember reading in my Chilton, Fuel pressure is 42psi (Someone correct me if I'm wrong)

 

I might just have to do a cam swap this summer ;) Delta-Cam 220 grind (If I have Slider rockers) I am thinking I might have Rollers as my buddys '95 duel-Port EJ22 did, so then I'd have to go with the 1000 grind.

 

Guess I'll find out when I do valve cover seals.

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Switching to the Delta Cams will make a difference. I really doubt you will need to worry about adding more fuel unless you get really crazy with modifications. Start with the Cams and perhaps some exhaust work and leave the fuel system stock for now would be my suggestion.

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Switching to the Delta Cams will make a difference. I really doubt you will need to worry about adding more fuel unless you get really crazy with modifications. Start with the Cams and perhaps some exhaust work and leave the fuel system stock for now would be my suggestion.

 

 

Yeah I was thinking the same, I was testing the waters on injectors as they are a quick swap, but then again, so are cams for the most part.

 

I am running an UEL Header which has given me more low end torque, whether its hurt my higher power-band, I'm not sure. I do feel the power-band come to life around 3500-5000rpm (Which is basic for any Subaru) I suppose the key to still having Low and high end power is to leave the 1-7/8" size pipe for the header (Don't exceed 2") then bump it up to 2.25" stright pipe all the way back.

 

Again, thanks for the advice :)

 

-Tom

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