ok prop fuel is at about zero and oscillation still sucks...
12-01-2005, 09:50 PM
#5
proportional fuel is a way to get the o2's to overshoot and undershoot. increase it if its undershooting too much...reduce it if its overshooting too much.......turn it to 0 if its still overshooting too much...
sometimes people think their o2 have bad switching and are not getting hot enough..reality is that they might just be getting too much overshoot causing Hang time and need to be turned down so that the switch
sometimes people think their o2 have bad switching and are not getting hot enough..reality is that they might just be getting too much overshoot causing Hang time and need to be turned down so that the switch
12-01-2005, 10:27 PM
#6
yea i understand that, but if you take out the proportional fuel you take out the control you have on fuel being added or subtracted to switch around the switch point, so you shouldnt switch at all if it is at zero? and if it switches shitty still i guess you are screwed, you cant put negative numbers in there can you lol
12-02-2005, 12:07 AM
#7
unfortunately you cant put negative numbers in there as far as I know....
there is a generic starting point built in that basically says its gonna purposely overshoot/under shoot by some amount(stft's show this)..thi samount is minimal...but it doesnt mean that 0 will not switch at all...thats all completely car dependent...some cars still have enough stuff going on to switch no matter what...especialy if they have bigger injectors that cant go down to as small of a pulse as stockers can...
anyways this table is just an adder to that small predefined unchangeable amount(I'm sure if you really wanted to you could hack a bin and change that...but thats too much work..and I dont care to do the R&D on that)
there is a generic starting point built in that basically says its gonna purposely overshoot/under shoot by some amount(stft's show this)..thi samount is minimal...but it doesnt mean that 0 will not switch at all...thats all completely car dependent...some cars still have enough stuff going on to switch no matter what...especialy if they have bigger injectors that cant go down to as small of a pulse as stockers can...
anyways this table is just an adder to that small predefined unchangeable amount(I'm sure if you really wanted to you could hack a bin and change that...but thats too much work..and I dont care to do the R&D on that)
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12-02-2005, 08:32 AM
#9
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What's the table number in HPTuners for proportional fueling? I'm just curious what it corrolates to in EFILive, as you are the only two I've ever heard talk about it. 
12-02-2005, 12:08 PM
#11
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Proportional fuel will make them oscillate even
when things are perfect (all injectors dead matched
and fueling trimmed to target).
Given any injector imbalance, you will see O2
excursions about center (especially at lower RPM
there there is no "averaging" in the pipe, you can
see individual cylinders' mixture sequentially; some
control schemes attempting per-cylinder trimming
I have seen described but don't know of any on
the road).
when things are perfect (all injectors dead matched
and fueling trimmed to target).
Given any injector imbalance, you will see O2
excursions about center (especially at lower RPM
there there is no "averaging" in the pipe, you can
see individual cylinders' mixture sequentially; some
control schemes attempting per-cylinder trimming
I have seen described but don't know of any on
the road).