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hp limits on 255 pump
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[QUOTE]Originally posted by Jeff S: [QB] [b]Class is now in session.[/b] Take the following [b]facts[/b] and draw your own conclusion: Duty cycle is the proportion of time during which a component, device, or system is operated. The duty cycle can be expressed as a ratio or as a percentage. Duty cycle when refering to fuel injectors is the amount of time, in a percentage, that an injector is "open" relative to the amount of [b]AVAILBLE[/b] time for the injector to be "open". In a sequential system, which fires one injector after another, the injector fires once per intake valve event(1 combustion cycle or 720* of crank rotation or 360* cam rotation). At a given [b]RPM[/b] there is only a specific amount of time in which the injector can fire per intake valve event(IVE). Lets use 6000rpms for example: At 6000rpms there are 3000 IVE's per minute. So... there are 3000 IVE's in 60 seconds. Or...300 events in 6 seconds...50 events in 1 second which if you keep doing the math gets you to 1 IVE per .02 seconds which is the same as 20ms(milliseconds). This means that there are 20ms between IVE's. If the injector fires for 10ms per IVE that means that it is at 50% duty cycle. If the injector remains open the entire 20ms it is at 100% duty cycle. [b]This is what Sawson doesn't understand[/b]. If at 6000rpms there are 20ms of time bewteen IVE's you have less time for the injector to potentially fire then you do at 3000rpms. This is because at 3000rpms there is twice the amount of time for the injector to be open(40ms) between IVE's. And at 8000rpms there is less time for the injector to be open(15ms). Therefore if you have a motor that makes 400hp at 6000rpms it will not need as large of an injector flow rate as an engine makeing 400hp at 8000rpms. ANY QUESTIONS? :p [/QB][/QUOTE]
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