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View Full Version : Something for the MAF guys to ponder



Dirk Diggler
May 19th, 2005, 04:33 AM
I would try this myself but dont have a maf anymore but here is my idea.


I propose instead of ve tuning do maf tuning instead. Make a frequency map with rpm=8000 and plot freq against AFR or Base numerator efficiecy factor and increase/decrease your maf as needed. What are your general thoguhts on that...

My reasoning behind this is. With ve tuning all we are doing is calculating a new ve table based on AFR's. After most are finished with this they then plug their maf back up and fail it so they can retain frequency. Then log dynamic air against the frequency and enter the values plotted in g/sec straight into the maf table. Dynair and maf air should now be dead on or close in value.

Well my idea would eliminate the ve tuning step and can be used to just come up with a new maf table and calling it quits.

Few questions i have about this

1. If the ve table is left alone what would happend when the pcm sees unstead map values and blends say 50/50 maf and ve.

2. Would this even work?

3. What FTC cells have more maf bias, map bias and what cells are completely maf or map?

Steve Bryant
May 19th, 2005, 08:20 AM
Dirk,
I believe that your thoughts have merit. However, it is my understanding from the research plus the tuning and experimentation that I've done that the measured dynamic mass air flow data (when used) works in conjunction with the predicted speed density values for dynamic mass air flow based upon the Main VE cell values (MA versus RPM), IAT, displacement and ECT. Therefore, if you just try to set up the AFR based on logged MAF dynamic air flow data, you will be in fact compensating for any errors in the Main VE Table that do not reflect your engine.

Regards,

Steve