LTFT on stock car

[Hondanickx]

Here's one from when the engine was cold ,the lower rpms are much worse.
These where all done on the highway cruising .The previous one had 1 short WOT pull in 5th gear which i marked in red.
I'll try to do some more logs tomorrow and also include The TPS%.

 

[PowerPerLiter]

If the lower rpms are any worse than what I am seeing then I retract my previous statement.

And if you are actually seeing anything near 12.0 afr then I would 100% return it to stock. There was likely nothing wrong before the si lid was installed.

The air flow meter calibration is more than just important for maintaining proper air fuel ratios. Its referenced for timing changes, cam angle changes, boost control etc. The car uses that signal to approximate actual cylinder fill as well.

Much more critcal component than people are used to with these cars.

And to add more emphasis....even the bellmouth angle and surface type of the material used drastically affects the calibration....breathe on the thing wrong and its off basically.....lol

 

[Hondanickx]

If the lower rpms are any worse than what I am seeing then I retract my previous statement.

And if you are actually seeing anything near 12.0 afr then I would 100% return it to stock. There was likely nothing wrong before the si lid was installed.

The air flow meter calibration is more than just important for maintaining proper air fuel ratios. Its referenced for timing changes, cam angle changes, boost control etc. The car uses that signal to approximate actual cylinder fill as well.

Much more critcal component than people are used to with these cars.

And to add more emphasis....even the bellmouth angle and surface type of the material used drastically affects the calibration....breathe on the thing wrong and its off basically.....lol

No the worst lower rpm is what i just posted. I'm more concerned about the WOT run and those AFR which are lean (to me atleast).
According to Drob the stock calibration targets 14.7AFR for a period of time in WOT .So that can explain the 13-14AFR between 2660rpm and 3427rpm.But the 13:1 afr at 5026rpm is scary ...

 

[fenix-silver]

No the worst lower rpm is what i just posted. I'm more concerned about the WOT run and those AFR which are lean (to me atleast).
According to Drob the stock calibration targets 14.7AFR for a period of time in WOT .So that can explain the 13-14AFR between 2660rpm and 3427rpm.But the 13:1 afr at 5026rpm is scary ...

Don't forget that the AFR target is also dependent on load, so you can be at higher RPMs and lower load values where the target AFR is leaner than what it would be under full load, like so:

 

[Hondanickx]

Don't forget that the AFR target is also dependent on load, so you can be at higher RPMs and lower load values where the target AFR is leaner than what it would be under full load, like so:

Thx didn't thought about that .
I will do some more logs tomorrow and post them here .
I'm used to the older civic's and their tuning but the newer cars and their engine mangement are so much more advanced these days.
I knew the MAF housing was sensitive ,but didn"t knew it was THIS sensitive.
At least i'm learning something new here

 

[PowerPerLiter]

Don't forget that the AFR target is also dependent on load, so you can be at higher RPMs and lower load values where the target AFR is leaner than what it would be under full load, like so:

And that is the kicker right there. The load factoring could be all over the place in those cells that are 15-20 units of adjustment on the s.trim.

According to Drob the stock calibration targets 14.7AFR for a period of time in WOT .

Yes they can and do. I have heard audible strong pinging because of this on my last Si ('18)

 

[Hondanickx]

Did a few more logs today .This time added tps%.From left to right
STFT, TPS% ,AFR ,RPM.
Wot is 78% tps.

1 wot run and some general driving.
All in all it seems to be ok ?
What do you guys think?
The higher fluctating STFT seems to only happen when i'm backing off throttle.So i think that's normal?
The initial lean AFR in wot runs seems also to be normal ,Because the OEM calibration does this?

 

[PowerPerLiter]

Really does look good/normal! Maybe that can be a new "mod" for the non-si guys.

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