So I am poking around my Motec Software and discover I can adjust how much fuel comes from the primary and seconday injectors at any given time.



It is setup right now for 100% primary at low load low RPM and eventually rises to a 50/50 ratio at full load high RPM.



550 primaries and 1300 secondaries.



It does not seem I would want a 50/50 ratio as the secondaries are so much bigger.



Am I right on this?? Would I want more of the secondaries at high boost high RPM??





I mean the max output of my primaries at 80% duty cycle would be 440cc



So that means the most my secondaries will pump is 440 to match the primaries or would they pump 80% of 1300 being 1040??



O.K. now my brain hurts.

 

your primaries are ~30 %(29.729) of your total fuel delivery (100% = 1850)



so it should be 30/70

 

They could just mean the amount of time they're open is 50/50. Therefore you second statement should be correct.



I think from your description it works like most have their Haltech setup. Up to a certain point the primaries do all the work (100%). After that point (staging bar) each injector opens exactly the same amount of time (50/50).



So on one bar the primaries might be open 6ms, then the next one they drop to 2.5ms and the secondaries come on for 2.5ms as well.



The other way of doing it would have the primaries increase towards 90% of their capacity and stay there (say 5.5ms). The secondaries then come on to provide additional fuel in the next bar (starting from 1ms)

 

yah tyson is right, the ecu doesnt know how big the injectors are, just the open time, so 80% is 80%, so you'll get 550x .80 + 1300*.80 for a total of 1480*cc's of fuel



mike



*this is of course not taking in acount fuel pressure, injector tolerances, the phase of the moon and oprah's wieght



mike

 

I remember inputing in another place a number to let the Motec know that the secondaries are a percentage bigger then the primaries.



Let me look. I might contact a friend of mine that has a motec in a FC putting down 360RWHP and has been for over 3 years now without a problem.

 

hmm yeah i would do that, he knows more than i do about the motec



mike