what duty cycle are injectors at their best?
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what duty cycle are injectors at their best?
Question: What duty cycle does an injector work at it's optimum? 70%?80%
The reason I am asking is if your have a programmable computer does it matter if your injector is only working at 50%? For example: would 550cc primaries running at 70% duty cycle be very much different than 850cc primaries running at 60% duty cycle? Are the spray patterns that different between the two?
The reason I am asking is if your have a programmable computer does it matter if your injector is only working at 50%? For example: would 550cc primaries running at 70% duty cycle be very much different than 850cc primaries running at 60% duty cycle? Are the spray patterns that different between the two?
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I guess I should ask if there will be a noticable difference running 550cc primaries vs 850cc primaries given that I have a programmable computer?
#3
They work great up to 80-85%, at which point they are reported to just stay open. They probably don't work too well at like 1% either, but I don't think that is your concern.
I don't think duty cycle is the relevant issue, but smaller injectors like 550s (still huge compared to most automotive injectors) are said to have a better spray pattern than larger injectors. The spray pattern is important for a good idle and low speed drivability. Of course that does lead us to the possibility that a larger injector might butt up against the low end of the duty cycle scale, but I am not sure if that is the case or not.
So, 550 primaries give a good idle and low speed drivability, regardless of their duty cycle. 850s are probably worse in these regards, but I am not sure how significant the difference is. It might be imperceptable, or it might make the car idle like crap, I'm just not sure.
-Max
I don't think duty cycle is the relevant issue, but smaller injectors like 550s (still huge compared to most automotive injectors) are said to have a better spray pattern than larger injectors. The spray pattern is important for a good idle and low speed drivability. Of course that does lead us to the possibility that a larger injector might butt up against the low end of the duty cycle scale, but I am not sure if that is the case or not.
So, 550 primaries give a good idle and low speed drivability, regardless of their duty cycle. 850s are probably worse in these regards, but I am not sure how significant the difference is. It might be imperceptable, or it might make the car idle like crap, I'm just not sure.
-Max
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The problem is not the upper duty cycles, but the lower duty cycles. Injectors work fine down to 5% (that is what most people say), but below that they start to become inconsistant and that will give you a rough idle.
4% duty cycle is fine on a few cars I have tuned, but anythign below that you start to run into problems and have to bump the idle up.
4% duty cycle is fine on a few cars I have tuned, but anythign below that you start to run into problems and have to bump the idle up.
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