Duty cycle

[Würstchens-Turbo 810]

Hi how important is the "Duty Cycle" in the PCIIIusb Software for us ?

I dont understand this

[mankam]

it's never too late for an answer

“Duty Cycle” displays the percentage of time the injector is open during one cam revolution (fuel cycle). In advance mod, it's the percentage of time for each cylinder's duty cycle. Without the Power Commander, the Duty Cycle is controlled by the ECU


Here is a video that explains:

[Würstchens-Turbo 810]

Hi Thanks .
My (the) Power Commander3usb not shows a Duty Cycle Area.
But i use the innovate SSi-4 Box for Data recording and this Box can show Duty Cycle but i dont know how ,
i dont know which wire , out from Injektor ) is positiv and which is ground .
Pur Injektors open by ground or open by + . ?

[DEATH_INC.]

Injectors are normally controlled by the - or negative (ground) wire. The + positive one should power up when the key is turned on.
- wire is yellow on the stock bike, and + is red/white.

[Würstchens-Turbo 810]

Thank you very much

[Würstchens-Turbo 810]

hi again after a few years
Please how to show Duty cycle in my PC3 usb
i see only

throttle
upm
Fuel change
zyklus ( what is it ?)

[Würstchens-Turbo 810]

hi again after a few years
Please how to show Duty cycle in my PC3 usb
i see only

throttle
upm
Fuel change
zyklus ( what is it ?) Edit >> ITS Duty Cycle

[Charlie @ Evergreen]

Hopefully someone with experience in PC will answer soon Horst

[Lorcan]

Duty cycle is the amount of time an injector is open, as a percentage of the amount of time available. As rpm increases, and the engine spins faster, the amount of time available to inject the fuel decreases. At 10,000rpm, there is about 12m/s (milliseconds) in which to open the injector, squirt the fuel, and close the injector again, ready for the next cycle. This assumes one squirt per two crank revolutions, completing the four stroke cycle.

The time spent opening and closing the injector, where the full amount of fuel flow is not possible, is known as dead time. This also varies according to voltage supply, which jerks the injector open. Injector manufacturers usually make a table showing the effect of voltage on dead time, if you ask. On our dragbike we build a compensation table to allow for this,using the manufacturer data.

So at 10,000rpm 6 milliseconds of open injector would be 50% duty cycle. At 5000rpm 6 milliseconds would be 25% duty cycle, as there is twice as much time available but the same amount of fuel going in. Capiche?

Modern injectors can flow fuel down to around 1 millisecond of on time, older ones are more like 2m/s, and it's not a good idea to exceed around 85% duty cycle, as the dead time can cause instability above this, leading to non-linear fuel flow.