How does one test the maxium injector duty cycle with OBD-2 logging software?
Thanks...

 

Injector Pulewsidth(msec) * RPM / 1200 = Duty Cycle (in percent)

 

EFILive V6 has this calculation built in, too.
But you have to select the pulse width param
to be logged, and you're probably best off
doing the calc afterward to free up resources
if your computer is slow.

 

Duty cycle %= inj.PW(mS)/(RPM/30000)

This is electrical duty cycle - remember your actual mechanical open time will be shorter. General target is not to exceed 80% DC Jason

this is from a guy at www.mototron.com i think he knows what's up. check this out too http://www.ecanfix.com/~mdhamilton/dutycycle1.html

 

Are you sure that formula is for duty cycle?
For example, if RPM=4000 and pulse width=24ms the duty cycle should be 80%
That formula gives: 24/(4000/30000) = 180%
The table that you linked to is correct though.
The correct formula for duty cycle is the one ChrisB posted.

Regards
Paul

 

you know, i tried that formula AFTER i posted it and it doesn't work out for me either. i do believe that the duty cycle/PW formula whatever it is is a constant for any injector though. if that is the case, the table i have a link to should be correct.

anybody else have any input here?

 

Question:
so is this formula correct:

inj.ms x rpm/1200 = duty cycle?

Thanks..

 

yes, or you can use the link to the table i posted above

 

i sent an e-mail to the guy at mototron that told me that. we'll see what he has to say.

 

ok, he screwed up. that was an injector timing table of some sort that he sent me. the other one is right on. he says just a shorter version of this

Duty cycle %= inj.PW(mS)/(1/(RPM/60000)2)*100

 

Right on, here's the simplification...

dc = (pw/((1/(rpm/60000))*2))*100
dc = (pw/(2/(rpm/60000)))*100
dc = (pw*((rpm/60000)/2))*100
dc = (pw*(rpm/120000))*100
dc = pw*(rpm/1200)
dc = pw*rpm/1200

(Hope that's right - been a long time since I did algebra at school.)

Paul

 

OUCH! too much information! i like the simple equasion myself.

 

Terminator:
...that is a simple equation posted by EFLive:

the last line is the same formula given to me in the first post

duty cycle = injector pulse in milliseconds x RPM/1200