Experiment - Alternate Method Tuning MAF
We can calculate the Mass Airflow in lbs/min using certain variables outside the MAF Sensor. If done right, we should be able to get the PROPER table settings to tune the MAF Table.
Logging your Fuel Pressure or having your injectors flow tested will enhance accuracy but is not a must to tune this way.
This tune method requires.....
Injector Pulsewidth, RPM, Intake Air Temps and Wideband or AFR CMD
If one doesn't have a wideband this still can be done at idle only with AFR Commanded. So as long as the Commanded AFR and Narrowband O2 agree on stoich. In that case multiply the entire MAF table by the percentage it takes to get the idle rated tables in line.
Fuel Flow lb/hr = ((( PulseWidth x RPM ) / 1200 ) x 0.01 ) x Injector Rating at 100%DC
MAF: Air Flow lb/min = ( Wideband AFR x Fuel Flow lb/hr ) / 60
TVE: Theoretical 100% VE = ( Displacement x RPM ) / 3456
VE% = ( MAF / TVE ) x 100
**Note: My Injectors meet stoich at 34.4 lb/hr @ 14.35:1 , yours will be different.
VE Insert Formula:
(((( AFR *(((( INJ PW * RPM )/1200)*0.01)* INJ lb/hr ))/60)/((491.67/(459.67+ IAT ))*0.0808))/(( Cubic Inch Displacement * RPM )/3456))*100
VE Insert for a 3100v6 with 34.4lb (36lbers from L67) injectors:
(((([SENS.121]*(((([SENS.112]*[SENS.70])/1200)*0.01)*34.4))/60)/((491.67/(459.67+[SENS.11]))*0.0808))/((191.732*[SENS.70)/3456))*100
VE Insert for a 3400v6 with 34.4lb (36lbers from L67) injectors:
(((([SENS.121]*(((([SENS.112]*[SENS.70])/1200)*0.01)*34.4))/60)/((491.67/(459.67+[SENS.11]))*0.0808))/((204.88*[SENS.70)/3456))*100
MAF lb/min Insert 34.4lb (36lbers from L67) Injectors:
([SENS.121]*(((([SENS.112]*[SENS.70])/1200)*0.01)*34.4))
The MAF Insert can be used against a MAF Freq Histogram to get the proper lb/min rating per frequency.
If this is done through idle using commanded AFR at stoich, divide actual MAF lb/min by rated MAF lb/min to obtain the number used to multiply the entire MAF table with.
This Insert will provide a number to multiply the MAF Table by: For idle tuning the MAF
([SENS.121]*(((([SENS.112]*[SENS.70])/1200)*0.01)*34.4))/[SENS.40]
Most of this stuff is new and not fully tested. Use these at your own risk as I am not responsible for any errors I may have made.
Hopefully, there could be some insightful points posted up.