Dale McPeters
03-18-2007, 08:18 PM
I do not remember who sent me this, I would like to thank whoever it was...:metal:
Here are some notes on LA3 MAF Conversion >
The information contained in this document is for someone who is using the Tweecer on a LA3 EEC-IV for the 2.3 Ford Turbo and wants to do a MAF conversion. This information should only be considered a reference to a MAF conversion. I’m in no way an expert in programming the LA3 EEC-IV to do a MAF conversion. There may be a lot more things to change but this did work for me and worked very well. Hopefully people will read this and learn from it so this document can be improved upon.
Basically what I’m saying is that I’m not responsible if you use this information and screw up your engine. My engine has 186,000 miles on it and I drive it to and from work everyday and on the weekends I run the dog---- out of it. I have not had any problems relating to the MAF conversion on my engine to date. Except for a smoother idle, better throttle response, smoother power band and a cool sound when you shift gears. Give it a try; it worked for me.
Air Mass Transfer Function: (F_1010) "Y" column = 0.19611 in CalEdit; refer to A9L-AMT-LA3.xls for the Air Mass Transfer Function numbers that I used.
In order to convert a VAM (measures CFM) to MAF (measures Air Mass) we will need to bypass the Air Mass Transfer calculation in the fuel equation. Making all of the "Y" column values the same makes it impossible for variations in barometric pressure and ambient temperature to affect the EEC's fuel calculation via the BAP and VAT sensors. Since a MAF will provide a direct measurement of air mass we can leave this task up to the MAF sensor from now on.
Mass Air Multiplier: (P_1220)
If you leave this value set to 1 it will give you a max airflow of 32lbs/min. Changing this number to 1.9999 will give you a max airflow of 64lbs/min. Only change this to 1.9999 if you have a motor that can move more than 32lbs/min of air.
CLRW: (P_2F70)
REG_3A: (P_2F71)
You will need to change (P_2F70 and P_2F71) to (255) if you have a motor that can move more than 32lbs/min of air. The max airflow limit will now be 64lbs/min of airflow.
# of VAF samples to average at idle: (P_06AA)
Changing this value from 1 to 3 will improve idle quality.
VAF min continuous: (P_16EA)
The VAM will produce a voltage signal with just the key on but the motor not running. The MAF will not produce a voltage signal unless the motor is running. So we will need to change P_16EA from (0.170898) to (0).
VAF KOEO min: (P_1706)
The VAM will produce a voltage signal with just the key on but the motor not running. The MAF will not produce a voltage signal unless the motor is running. So we will need to change P_1706 from (0.170898) to (0).
VAF Transfer Function: (F_1038) I used a stock A9L MAF sensor (part# E9ZF-12B579-AA) refer to A9L-MAF-LA3.xls for the VAF Transfer Function numbers that I used.
I have a lot of time in getting the VAF Transfer Function numbers right for my application. You may need to change these numbers for your application especially if you use a different MAF sensor. I used a wideband O2 sensor to tune the VAF Transfer Function numbers. My results were 11.5.1 A/F @ WOT from 3000 rpm to 6000 rpm. My engine setup consist of: stock crank, stock rods, stock pistons, stock head, stock cam, stock intake manifold, stock exhaust manifold, stock T3 turbo, stock Thunderbird intercooler, stock throttle body, LA3 EEC-IV, Tweecer RT, A9L MAF sensor, 42lb fuel injectors, 190lph fuel pump and 3inch down pipe. The fuel pressure is set at 43psi, base timing was 13 degrees BTDC, spark plugs gapped at 0.30 and the turbo boost was 19psi. The engine has 186,000 miles on it and made 236 rwhp with this setup.
These are other changes I made to the A9L-MAF-LA3.CCF but have nothing to do with the MAF conversion:
P_141E Spark max (was 60) changed to (63) in CalEdit
P_04CF Force open loop fuel (was 0) changed to (1) in CalEdit
P_07D2 Force idle open loop (was 0) changed to (1) in CalEdit
P_1178 Injector Size (was 34.9923) changed to (37.0016) in CalEdit
P_0402 Air volume multiplier (was 0.318695) changed to (0.31868) in CalEdit
M_05E0 Base Fuel Table (completely changed using CalEdit) refer to A9L-BFT-LA3.xls for the numbers that I used.
M_OC8C Premium Ignition Table (completely changed using CalEdit) refer to A9L-PIT-LA3.xls for the numbers that I used.
M_OD47 Regular Ignition Table (completely changed using CalEdit) refer to A9L-RIT-LA3.xls for the numbers that I used.
Here are some notes on LA3 MAF Conversion >
The information contained in this document is for someone who is using the Tweecer on a LA3 EEC-IV for the 2.3 Ford Turbo and wants to do a MAF conversion. This information should only be considered a reference to a MAF conversion. I’m in no way an expert in programming the LA3 EEC-IV to do a MAF conversion. There may be a lot more things to change but this did work for me and worked very well. Hopefully people will read this and learn from it so this document can be improved upon.
Basically what I’m saying is that I’m not responsible if you use this information and screw up your engine. My engine has 186,000 miles on it and I drive it to and from work everyday and on the weekends I run the dog---- out of it. I have not had any problems relating to the MAF conversion on my engine to date. Except for a smoother idle, better throttle response, smoother power band and a cool sound when you shift gears. Give it a try; it worked for me.
Air Mass Transfer Function: (F_1010) "Y" column = 0.19611 in CalEdit; refer to A9L-AMT-LA3.xls for the Air Mass Transfer Function numbers that I used.
In order to convert a VAM (measures CFM) to MAF (measures Air Mass) we will need to bypass the Air Mass Transfer calculation in the fuel equation. Making all of the "Y" column values the same makes it impossible for variations in barometric pressure and ambient temperature to affect the EEC's fuel calculation via the BAP and VAT sensors. Since a MAF will provide a direct measurement of air mass we can leave this task up to the MAF sensor from now on.
Mass Air Multiplier: (P_1220)
If you leave this value set to 1 it will give you a max airflow of 32lbs/min. Changing this number to 1.9999 will give you a max airflow of 64lbs/min. Only change this to 1.9999 if you have a motor that can move more than 32lbs/min of air.
CLRW: (P_2F70)
REG_3A: (P_2F71)
You will need to change (P_2F70 and P_2F71) to (255) if you have a motor that can move more than 32lbs/min of air. The max airflow limit will now be 64lbs/min of airflow.
# of VAF samples to average at idle: (P_06AA)
Changing this value from 1 to 3 will improve idle quality.
VAF min continuous: (P_16EA)
The VAM will produce a voltage signal with just the key on but the motor not running. The MAF will not produce a voltage signal unless the motor is running. So we will need to change P_16EA from (0.170898) to (0).
VAF KOEO min: (P_1706)
The VAM will produce a voltage signal with just the key on but the motor not running. The MAF will not produce a voltage signal unless the motor is running. So we will need to change P_1706 from (0.170898) to (0).
VAF Transfer Function: (F_1038) I used a stock A9L MAF sensor (part# E9ZF-12B579-AA) refer to A9L-MAF-LA3.xls for the VAF Transfer Function numbers that I used.
I have a lot of time in getting the VAF Transfer Function numbers right for my application. You may need to change these numbers for your application especially if you use a different MAF sensor. I used a wideband O2 sensor to tune the VAF Transfer Function numbers. My results were 11.5.1 A/F @ WOT from 3000 rpm to 6000 rpm. My engine setup consist of: stock crank, stock rods, stock pistons, stock head, stock cam, stock intake manifold, stock exhaust manifold, stock T3 turbo, stock Thunderbird intercooler, stock throttle body, LA3 EEC-IV, Tweecer RT, A9L MAF sensor, 42lb fuel injectors, 190lph fuel pump and 3inch down pipe. The fuel pressure is set at 43psi, base timing was 13 degrees BTDC, spark plugs gapped at 0.30 and the turbo boost was 19psi. The engine has 186,000 miles on it and made 236 rwhp with this setup.
These are other changes I made to the A9L-MAF-LA3.CCF but have nothing to do with the MAF conversion:
P_141E Spark max (was 60) changed to (63) in CalEdit
P_04CF Force open loop fuel (was 0) changed to (1) in CalEdit
P_07D2 Force idle open loop (was 0) changed to (1) in CalEdit
P_1178 Injector Size (was 34.9923) changed to (37.0016) in CalEdit
P_0402 Air volume multiplier (was 0.318695) changed to (0.31868) in CalEdit
M_05E0 Base Fuel Table (completely changed using CalEdit) refer to A9L-BFT-LA3.xls for the numbers that I used.
M_OC8C Premium Ignition Table (completely changed using CalEdit) refer to A9L-PIT-LA3.xls for the numbers that I used.
M_OD47 Regular Ignition Table (completely changed using CalEdit) refer to A9L-RIT-LA3.xls for the numbers that I used.