NoPistons -Mazda Rx7 & Rx8 Rotary Forum - What Exactly Happens When.injector Duty =100%

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- - What Exactly Happens When.injector Duty =100% (https://www.nopistons.com/3rd-generation-specific-18/what-exactly-happens-when-injector-duty-%3D100%25-10979/)

my injector duty had risen as high as 96%(well that was the 297hp dyno) but still what happens when the injector duty gets to 100%. i know they lock up either open (where they will be spraying constantly) or they will lock up closed and u will run dry. or at least thats what i was told. i dont know like lets say it does to 100 whats gonna happen. will they definatly lock up or what?

also will getting bigger injectors help b/c it ust seems like they will be able to inject more fuel on each spray. not be able to spray faster. i dont know im talking jibberish cause im tiard and rambling. ]

just looking for some more info i have pretty much learned everything i know from forums and askin questions so feel free to go crazy and explain as much as u can. fuel systems are still very hazy for me, im working on that though. https://www.nopistons.com/forums/pub...IR#>/smile.png

i dont even wanna get started with ignition phew

anyway thanks id appreciate any and all info i can get.

-Mike

what size injectors do you have now?

i got th3e stockers what is it 550cc's and 850cc's

i wanna upgrade to the 1300cc's as soon as i have the money(oh well after i get caback https://www.nopistons.com/forums/pub...)

Duty cycle is the percent of the time the injector is spraying fuel. Over 85% is not recommended for reliability reasons. If you run to 100%, besides being bad for the injectors, your engine will not be getting enough fuel. (BAD)

Upgraded (i.e. larger) injectors will flow more fuel, PROVIDED that your fuel pump can suppy it.

If you are running at 96% duty cycle, the time to upgrade your fuel system is yesterday.

If I'm wrong anywhere here, please correct me!

They won't open and close correctly at 90% and over, you'll end up getting about the same fuel as around 60-70%...

you will lean out............

the factory ecu runs 85-90% duty

mike

1988RedT2,

Curious to know what the stock duty cycle (%) is? How is that measured?

the stock ecu will run about 85-90%, you can hook it up to an oscilloscope

mike