Jump to content

Targeted afr reads 11.35 when target table is set to 10.9


Wildt267

Recommended Posts

link 104x.  As stated around 20+ psi i'm hitting mid 11's for afr when map is set to 10.9 in the afr target table. Logs indicate targeted afr is 11.35 Checked iat table and its zero'd in most of that area.  I dug through looking for a specific correction responsible but was unable to determine what was happening.  I apologize for using afr and not lambda.  I just can't get my head around it.  So what am i missing here?v86 sti v11 knock settings and cold start settings.pclx

v86 sti v11 knock settings and cold start settings.pclx

Link to comment
Share on other sites

Do you have a log showing the target of 11.35 @ 20psi, I dont see any way that would be commanded from your map.  

You have the lambda target overlay table turned on but that only has a value at 0RPM and -20°C so that wouldn't have had any effect when the engine was running. 

Also be aware you have the stoichiometric ratio set to 14.13:1 in the ecu, so if you are viewing the target AFR of some 3rd party device that has a hard coded 14.7:1 stoich ratio then you will certainly observe different values that the ecu is commanding.   

Link to comment
Share on other sites

I did in fact set the stoich ratio to 14.13 as  i am using 10% ethanol in my fuel. I am using an Aem x-series wideband which i believe is as you describe but i thought that was a display issue only. So is the wideband then feeding incorrect information into the ecu?  Should i set stoich ratio back to 14.7? I am including the requested log. You will see the issue above 15psi of boost pressure.

I took your advice and applied the v11 knock settings to my map and selected 7khz narrow band.  Since you will be poking around the datalog anyway is the knock data what you would expect? I  Ive never had this advanced of knock control so everything looks noisy to me.  As always i greatly appreciate your help.

1135 target afr.llgx

Link to comment
Share on other sites

The gauge will see lambda and multiplier for what ever the manufactured decided and show it to you in AFR, because you are reading the signal coming from the gauge I would just tell the ecu stoich is 14.7. Because you are actually seeing the equivalent of lambda multiplier by 14.7 (guessing AEM is using 14.7), just run them as pump gas. 

Link to comment
Share on other sites

The AFR target appears to match the table from what I see.  There are a couple of small deviations just when it is starting to come on to boost quickly but these are because you have only logged the AFR target at 5Hz, so there is a bit of lag as you move through cells. 

For the knock you will need to set the retard limit to something appropriate (say -4), allocate the cyl trim tables, change frequency to 8KHz and add more of the knock data to the logging. 

kiSJ1PG.png

Link to comment
Share on other sites

Thank you for the knock setting advice, i am eager to implement it.

I am extremely confused by the screen shot however. At the spot you highlighted my software shows a lambda target of 11.23 and an actual afr of 11.8.  Am i going crazy here?  The file i'm viewing matches the 974 k file size displayed in the thread so it's got to be the same file.

I will follow the advice of the previous poster and switch the stoich ratio back to 14.7.

Link to comment
Share on other sites

1 hour ago, Wildt267 said:

I will follow the advice of the previous poster and switch the stoich ratio back to 14.7.

That will mess up your tune as you are telling the ecu it needs to inject a smaller proportion of fuel for the calculated air mass.  

 

1 hour ago, Wildt267 said:

I am extremely confused by the screen shot however. At the spot you highlighted my software shows a lambda target of 11.23 and an actual afr of 11.8.  Am i going crazy here?  The file i'm viewing matches the 974 k file size displayed in the thread so it's got to be the same file.

Do you have your map open so the ecu knows the stoichiometric ratio it needs to use to display AFR?  Those values would suggest it is using 14.7 which could be because a map is not open, or you have someone elses map open that has a stoich ratio of 14.7 set.   But then that would not fit your story that the target table did not match the log as you would need the map open at the same time to see the target table?

 

gU34OuN.png

Link to comment
Share on other sites

Correct but not a second fuel pump, my primary fuel pump has a two stage controller. The car is jerky at lower rpm so i have it set to kick up after i get into a bit of boost pressure.  That's a good catch though.  I had a feeling my aftermarket fpr was having a hard time dealing with the pump but ive prioritized sorting out my boost control so i just haven't gotten to it yet.

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...