I had found a post over on the EFILive board about a instant mpg pid calculation, cant find it now. Anyone else see it and remember it or have a copy of it?
instant mpg pid??
- Thread starter Cobra#3747
- Start date
Mileage PID's are only effective if the main injector table is unmolested?
I would want to take:
Timestamp
MPH
Pilot microseconds
Main microseconds
Then you need to come up with a "general" formula that approximates the injector table.
I would want to take:
Timestamp
MPH
Pilot microseconds
Main microseconds
Then you need to come up with a "general" formula that approximates the injector table.
wow
that would be kinda handy,But ive never seen it?
Does it work off the same calc as the DIC uses?
that would be kinda handy,But ive never seen it?
Does it work off the same calc as the DIC uses?
I will give it a try this weekend (making a fairly accurate formula) BUT it cannot replace:
Known weight
Known speed
Fixed round trip loop (no one-ways due to wind and elevation)
Map mileage
Fuel receipts.
That is the only way to check mileage.
Known weight
Known speed
Fixed round trip loop (no one-ways due to wind and elevation)
Map mileage
Fuel receipts.
That is the only way to check mileage.
Unfortunately they eliminated the instant read in the LBZ, plus like you say it changes anyway as soon as we mess with injector pulse.
Only really would like to have it to have a quick look at how changes are effecting the mpg. Plus that way I think there would have to be some way that it wouldnt be effected by the changes we make with the pulse width. Although not sure how pressure change will be calculated.
I will look more to see if I can find the thread again over on the EFILive forum.
Only really would like to have it to have a quick look at how changes are effecting the mpg. Plus that way I think there would have to be some way that it wouldnt be effected by the changes we make with the pulse width. Although not sure how pressure change will be calculated.
I will look more to see if I can find the thread again over on the EFILive forum.
You might be looking for this post.
http://forum.efilive.com/showpost.php?p=46300&postcount=85
Just got EFILive myself and wondered the same for LMM. I think the calculation for LBZ and LMM differ. Maybe someone has one close for LMMs. But like mention many variables change depending acceleration from what I am seeing.
Brian
http://forum.efilive.com/showpost.php?p=46300&postcount=85
Just got EFILive myself and wondered the same for LMM. I think the calculation for LBZ and LMM differ. Maybe someone has one close for LMMs. But like mention many variables change depending acceleration from what I am seeing.
Brian
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Might not work on performance tunes.
We "lie" to the Main Inj Table so that mm3 of fuel is reported wrong. This is how we can pump 200+ mm3 of fuel when the table limit is 120mm3.
GM also lies to this table. I'm not sure why, but they do. They had to make a DIC Mileage table to adjust out their tweaks to the main injection table.
But if all you are adjusting is timing and boost, it doesn't matter if the reading is right or wrong, as you are using it for a benchmark: "Did the fuel demand go up or down at 70mph?"
We "lie" to the Main Inj Table so that mm3 of fuel is reported wrong. This is how we can pump 200+ mm3 of fuel when the table limit is 120mm3.
GM also lies to this table. I'm not sure why, but they do. They had to make a DIC Mileage table to adjust out their tweaks to the main injection table.
But if all you are adjusting is timing and boost, it doesn't matter if the reading is right or wrong, as you are using it for a benchmark: "Did the fuel demand go up or down at 70mph?"
(Some Constant*MPH) / ((Pilot Pulse Width + Main Pulse Width) * sqrt(Rail Pressure))
Would work regardless of table tweeking. I have a similar Calc-PID for equivalence Ratio (A/F mix).
Would work regardless of table tweeking. I have a similar Calc-PID for equivalence Ratio (A/F mix).
Pardon my ignorance but what figure should be used in place of "some constant" in your equation???
Thanks for sharing!