injection duty cycle
11-04-08, 01:35 AM
#2
Yes and no!
Injector Duty Cycle is a factor which is on the end of a lot of other factors and their calculation.
When you talk about your duty cycle, I bet you have a PFC.
So your duty cycle results from all the calculation in the PFC .
From base map (how long will the injectors stay open) over the correction map.
Injector setups, like lag time etc. At the end the duty cylce is your actuating variable.
So when you change a factor like fuel pressure to manipulate the counterpart of one of the functions Parts in the PFC .
When you enlarge the fuel pressure and (I donīt think so, but to complete the example) this would be the factor that the injectors let pass more fuel in the same time, you have to manipulate ... the counterpart would be the base map.
So to compensate the higher flow rate, you have to lower the numbers in the fuel maps (either base or correction map).
In the end you will have a smaller duty cycle.
BUT: First the example tells you that you donīt get smaller duty cycles just by having a higher fuel pressure. You have to retune the maps again!
AND the most important thing is: Injectors are a valve with a small hole. So they are simply pressure reducing valves.
When you enlarge the pressure on the inlet side of the "valve" you donīt enlarge the pressure on the outlet!
So, in my opinion, the only way to get your duty cycles down enough is getting bigger injectors and retune the maps in the PFC.
I hope that helped!
Kind regards
Marc
Injector Duty Cycle is a factor which is on the end of a lot of other factors and their calculation.
When you talk about your duty cycle, I bet you have a PFC.
So your duty cycle results from all the calculation in the PFC .
From base map (how long will the injectors stay open) over the correction map.
Injector setups, like lag time etc. At the end the duty cylce is your actuating variable.
So when you change a factor like fuel pressure to manipulate the counterpart of one of the functions Parts in the PFC .
When you enlarge the fuel pressure and (I donīt think so, but to complete the example) this would be the factor that the injectors let pass more fuel in the same time, you have to manipulate ... the counterpart would be the base map.
So to compensate the higher flow rate, you have to lower the numbers in the fuel maps (either base or correction map).
In the end you will have a smaller duty cycle.
BUT: First the example tells you that you donīt get smaller duty cycles just by having a higher fuel pressure. You have to retune the maps again!
AND the most important thing is: Injectors are a valve with a small hole. So they are simply pressure reducing valves.
When you enlarge the pressure on the inlet side of the "valve" you donīt enlarge the pressure on the outlet!
So, in my opinion, the only way to get your duty cycles down enough is getting bigger injectors and retune the maps in the PFC.
I hope that helped!
Kind regards
Marc
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