k real quick stock injecters run at a certain duty cycle(95%). now add a afc. bump up the duty cycle. then add new injecters at the same duty cycle. wouldnt the fuel going in with the bigger injecters be totally different. im new to this tuning set-up and am triing to learn as much as possible before changing my mods.

 

you have alot of reading to do. yes a bigger hole at 50% will dump more fuel than a little hole at 60% for a rough answer.

 

FYI, the duty cycle changes constantly with the throttle.
Its not a set amount, It is the percentage that the injector happens to be functioning on at any give moment. Gas it & the duty cycle increases, lay off the gas it goes down. So if you are hitting 95% duty cycle @ WOT(which is not good btw) and then you get bigger injectors and run everything else the same the duty cycle will generally run lower since you have increased the ability to spray more fuel with the large injectors. You generally would want to upgrade the fuel pump and the injectors. Larger injectors to spray more fuel and a high flow pump to deliver more fuel. Get it? You cannot program in duty cycles. They are just a measurement.

 

good info i understand it now thanks guys

 

you generally dont want to go over 85% duty cycle. I read that everything over that is pretty much the same

 

Generally is right. It's not a great idea, however I was getting away with 90% and MAX on occasion @ 15psi on a purple box with stock injectors,walbro, and straight exhaust. I ran that set up for a little over a year.

 

quick question guys, I have the apex avc-r and i am always monitoring my injector duty%. THey seem to work fine but occasionaly it will spike up for a split second to 90% or even 100% when I am at very low RPM's they are not stock they are 1200cc, any ideas?