MAF-based VE Calculation

[Monty]

Useful Histogram Formulae

MAF-based Dym_Air Calculation

- Dym_Air_Calc = (MAF X 120) / (#_Cyl X RPM)

MAF-based VE Calculation

- VE_Calc= (Dym_Air_Calc X IAT'in k' X 0.28705) / (Vol_Cyl X MAP)

This is on the calibrated success dvd 2 and he says "I can use this, if im really slick, i can plug this in to a histogram and make this the formula and plot the VE against the manifold pressure and RPM scales to use the mass air flow sensor to help me build a volumetric efficiency table from scratch"

well obviously im not slick lol.. been trying for hours to figure this out, though im able to do the math, just unable to be as slick as one needs to be to make a histogram out of it.. please someone rescue me

[Wnts2Go10O]

why would you do that with a sensor that is calibrated? if the calibration is off even a little, it will mess up your new table.

try this: http://redhardsupra.blogspot.com/200...ss-models.html


GMVE= IFR*IPW*AFRwb*(IAT+(ECT-IAT)*BIAS)/MAP

this can be used to do what u are trying to do minus the headache.

[Monty]

why would you do that with a sensor that is calibrated? if the calibration is off even a little, it will mess up your new table.

try this: http://redhardsupra.blogspot.com/200...ss-models.html


GMVE= IFR*IPW*AFRwb*(IAT+(ECT-IAT)*BIAS)/MAP

this can be used to do what u are trying to do minus the headache.

Anything is better than the table i have now. i don't have gmve

i am trying to tune my Main VE so that my truck will run

banish said it can be done that way with out a wideband

i quoted him in the first post.

So Gen3's have GMVE, im sorry i did not know this, thought the GMVE wasn't tell Gen4. opps. i should have been more clear with what i have .. here is my logs and tune

[Jabbott]

Interesting, if you ran your low speed air at 800 rpm and then calibrated your MAF, this table should turn out right. However the key is the data can only come from steady state running. You can't collect any data with a transient throttle going on. You set up a filter maybe to only start reporting cells with 500 plus hits.

[Monty]

Interesting, if you ran your low speed air at 800 rpm and then calibrated your MAF, this table should turn out right. However the key is the data can only come from steady state running. You can't collect any data with a transient throttle going on. You set up a filter maybe to only start reporting cells with 500 plus hits.

Well not for me, lol, i still cant figure out the histogram

[Jabbott]

It takes some time to get used to.

[Monty]

It takes some time to get used to.

Just can't figure out the math for the filter in-order for the histogram to work correctly as Banish describes it should ..

[schpenxel]

why would you do that with a sensor that is calibrated? if the calibration is off even a little, it will mess up your new table.

try this: http://redhardsupra.blogspot.com/200...ss-models.html


GMVE= IFR*IPW*AFRwb*(IAT+(ECT-IAT)*BIAS)/MAP

this can be used to do what u are trying to do minus the headache.

What units do all of these need to be in? I assume IFR/IPW need to work out to a unit of fuel mass. What about IAT/ECS? *K? What about MAP?

[redhardsupra]

IFR is in g/sec
IPW is in msec
IAT and ECT is in K
MAP is in kPA
the rest are dimensionless

[redhardsupra]

IFR is in g/sec
IPW is in msec
IAT and ECT is in K
MAP is in kPA
the rest are dimensionless

[mowton]

IFR is in g/sec
IPW is in msec
IAT and ECT is in K
MAP is in kPA
the rest are dimensionless

and BIAS is.......the keys to the crypt, the holy grail etc. etc. etc. :-)

Ed M

[schpenxel]

IFR is in g/sec
IPW is in msec
IAT and ECT is in K
MAP is in kPA
the rest are dimensionless

Thanks

and BIAS is.......the keys to the crypt, the holy grail etc. etc. etc. :-)

Ed M

That seems to be what I keep running into. Gah.