Air Charge Limit ignored?

[Caustic Gnostic]

I am getting 250-272% AIRC from around 4500-5100 RPM. My Calibration is set for a maximum air charge limit of 235% so this is maxing out my fuel pump to 100% sometimes. I am not sure what settings can override those limits. Does anybody have any idea? Thanks!

[Caustic Gnostic]

PRL p600 tune.fpcal

datalog0008.fpdl

[Hondata]

First try using the boost by ethanol limit (change for all ethanol values).

If that does not work then reduce the air charge limit table until you see airc decrease. That information will probably tell us why it is not looking at the table, or is applying another multiplier.

[Caustic Gnostic]

Thanks will do, as a side note this started happening after I installed the hondata MAF 500 sensor.

[jeffx]

your fuel trims are crazy out of whack (-12% LTFT), not sure what's going on there but that could be a good reason for the too-high AirC calcs

[Caustic Gnostic]

Yeah good point, that started with the new MAF as well. I figured it was because the intake still needed to be mapped properly but not sure why it is so rich...

[Caustic Gnostic]

Screenshot 2025-04-23 202422.png

Ok the boost by ethanol does not seem to be the culprit. I still hit 268% on a short pull after I limited that table to 235%. This run was also much better as far as LTFT I mapped the intake a little better and it is now at -4% LTFT so I don't believe that is the issue either. I will still need to lower the limit table even more and see when it starts to lower the boost, but that may take a while to test...

datalog4_23_25.fpdl

[Fkay8]

First try using the boost by ethanol limit (change for all ethanol values).

If that does not work then reduce the air charge limit table until you see airc decrease. That information will probably tell us why it is not looking at the table, or is applying another multiplier.

Hondata just a question why the boost by ethanol should be changed since the calibration have the ethanol input disable?

[Hondata]

Right, ethanol would have to be enabled. Skip that part then.

[Caustic Gnostic]

I am at a loss. I have lowered the AIRC limit to around 225% but I got a spike of 312% last run. Also from tuning the intake, the flow rates seem impossible now (but my AFM.v to STFT doesn't look too horrible) since based on my g/s rates I would be making ~460HP and 490FtLbs with a stock fuel pump and stock internals :'(

Is it possible that the AIRC calc is incorrect for some reason (it goes from 209% to 312% in an instant somehow)

I must be doing something wrong with the new MAF but I am not sure what...

Screenshot 2025-04-28 192826.png

Screenshot 2025-04-28 193040.png

datalog4_28.fpdl

Thanks for the help

[Rares]

First, try to uncheck "Increase air charge limit from 250" mod if you don't need this

Screenshot 2025-04-29 at 11.25.09.png

Another thing you can do is to tune the Turbo max air charge (IAT) table.

Screenshot 2025-04-29 at 11.26.40.png

Based on your log I don't think the Aircharge value is real, it has nothing to do with any other relevant parameters. It seems more like a bug or a sensor problem. The rest are just consequences: rich mixture, negative trims, high fuel pump duty.

[jeffx]

I am at a loss. I have lowered the AIRC limit to around 225% but I got a spike of 312% last run. Also from tuning the intake, the flow rates seem impossible now (but my AFM.v to STFT doesn't look too horrible) since based on my g/s rates I would be making ~460HP and 490FtLbs with a stock fuel pump and stock internals :'(

Is it possible that the AIRC calc is incorrect for some reason (it goes from 209% to 312% in an instant somehow)

I must be doing something wrong with the new MAF but I am not sure what...
Screenshot 2025-04-28 192826.png
Screenshot 2025-04-28 193040.png

datalog4_28.fpdl
Thanks for the help

can you post your latest calibration with the updated AFM table?

[jeffx]

also, which exact intake are you using?

[Caustic Gnostic]

Here is the calibration I used for the last data log. I had already unchecked the mod to allow greater than 250% AIRC.

4_28 calibration.fpcal

You can see I increased the flow on the MAF for >4V a pretty large amount.

Screenshot 2025-04-29 174814.png

Next I will work on decreasing values for the Turbo max air charge (IAT), thanks for that!

I am using the K&N typhoon intake.

[jeffx]

Here is the calibration I used for the last data log. I had already unchecked the mod to allow greater than 250% AIRC.
4_28 calibration.fpcal

You can see I increased the flow on the MAF for >4V a pretty large amount.
Screenshot 2025-04-29 174814.png
I am using the K&N typhoon intake.

I think this curve shape is quite very possibly contributing to your crazy airC readings and the ECU going into open loop right around that 3.9V AFM range. it should be a smooth curve more like this

kn_gnostic_afm.png