Modelled Fuel - Target AFR Table AFTER

[AlexSavv]

Hey guys.

I wanted to ask if there is a way that you can change the Target AFR Table AFTER the main fuel table has been turned, without it having an impact on the mail fuel table.

 

For example, when actually tuning a new engine you may not know the exact targets you want to use, after a tuning session is complete you might have found how the car likes to run.

From there, could you update the Target AFR Table to match what you have tuned to WITHOUT it having the open loop effect on the main fuel you have just tuned.

 

Thanks

[Electredge]

I think if you tuned in traditional fuel equation mode then it would work the way you are asking about 

[Adamw]

You're meant to tune the VE table so that the measured AFR matches the AFR target - it doesnt matter if that target is the actual target you will finally use as you can easily change it afterwards.  After calibrating the VE table if you want to try different AFR's you just adjust the AFR target.  So, if you have calibrated the VE table by targeting a different AFR than was in the AFR target table at the time, then your VE is now wrong.

If the load axis breakpoints on your AFR target table match your fuel table then you should be able to correct the VE table by multiplying a whole row by the same factor that you have changed the target table row by.  So if for instance you adjusted a row in the target table by say 3% leaner, then you want to increase any rows in the VE table that reference that part of the target table by 3% also.  This should end up with the target table corrected with little change to the final AFR. 

[AlexSavv]

9 hours ago, Adamw said:

You're meant to tune the VE table so that the measured AFR matches the AFR target - it doesnt matter if that target is the actual target you will finally use as you can easily change it afterwards.  After calibrating the VE table if you want to try different AFR's you just adjust the AFR target.  So, if you have calibrated the VE table by targeting a different AFR than was in the AFR target table at the time, then your VE is now wrong.

If the load axis breakpoints on your AFR target table match your fuel table then you should be able to correct the VE table by multiplying a whole row by the same factor that you have changed the target table row by.  So if for instance you adjusted a row in the target table by say 3% leaner, then you want to increase any rows in the VE table that reference that part of the target table by 3% also.  This should end up with the target table corrected with little change to the final AFR. 

This is exactly what i wanted to know! Thank you,

 

So my understanding now is, if I had my car tuned on VE, I could update the Target AFR table to MATCH the actual tune after (based on logs).

To do this I would workout the % difference in Target vs Actual AFR, apply the change in the target table (say +10% for example) and apply the opposite of this to the main table in-order (-10%) to equal it out.

Slight tweak from there to confirm.

Thanks Adam.

[Adamw]

correct.  it will unlikely be prefect in some areas as you will be interpolating between cells etc but you should be able to get it pretty close.

[dx4picco]

Not exactly, actualy if you want your afr table (namely AFR target in your log) to match the measured AFR you must modify your VE table, according to the error there is.

Once your measure AFR are in line with AFR target (what is in Target AFR table) THEN you can modify your target afr, lets say you want to run richer on pumpgas than on e85, you don't need to touch the VE table because its already correct and you only need to change values in the target Table.

In case you have the correct AFR you want, let's say 12.0 and in your trget AFR say 11.0 then you would would put your target table to 12.0 and at the same time increase the VE table from 9% in that region, and you would end up again with 12.0 AFR and a matching VE table

[Adamw]

13 minutes ago, dx4picco said:

In case you have the correct AFR you want, let's say 12.0 and in your trget AFR say 11.0 then you would would put your target table to 12.0 and at the same time increase the VE table from 9% in that region, and you would end up again with 12.0 AFR and a matching VE table

Thats exactly what he said he was going to do isnt it?

[dx4picco]

then it not being my mother tongue fooled me and didn't understand it that way. Sorry

[Adamw]

yeah, its definitely worded a bit different than how you say it, but I think they are both effectively the same technical statement.

Stupid english...

[AlexSavv]

Haha, thanks for the input guys.