MAF curve adjusting - need help to understand the formula

[Prozento]

Hello pals

I want to adjust my MAF section to get a better AFR rating (goes as rich as 8.3-9.8 on WOT while the target is 11.2) and normal LTFT in summer is 9-7%.
I used this video to understand the concept:


Now, I understand how he does it, but I don't understand the formula In his excel sheet - as you can see on the picture is =B7*(C7*0.01)+B7.
After collecting data from logging I need to make an average for example for 0.66 MAF.v and copy-paste the average of all the data into column C.
The slots numbers change but the idea stays the same for all the sheet. Can anyone please explain the logic behind it?

Best regards
Prozento

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[Gruber]

Well, your name is Prozento....
In this case you just put in columc C by how many percentage points you want to increase the corresponding value in column B. Then column D will show the result: B increased by C percent. This formua is just a trivial percentage increase calculation having nothing to do with any MAF intricacies or engine control knowledge.

 

[Prozento]

Well, your name is Prozento....
In this case you just put in columc C by how many percentage points you want to increase the corresponding value in column B. Then column D will show the result: B increased by C percent. This formua is just a trivial percentage increase calculation having nothing to do with any MAF intricacies or engine control knowledge.

The gap in my understanding was that the information I put in column C is Percentage too. Now it make sense.

Thanks for the reply

 

[kadireren]

The gap in my understanding was that the information I put in column C is Percentage too. Now it make sense.

Thanks for the reply

The video that you posted is mostly used for calibrating the fuel trims not the afr at wot especially if your car runs open loop at wot like me. With the help of the video you can adjust your short term and long term trims and if your can runs open loop at wot and your afr is 9s then if i were you i would decrease ten percent from 3.8 to 5v from your current maf table.
İf you don’t know it runs open or closed loop you can understand it from the short term trims or fuel stat. İf short trims are 0 at wot and fuel stat is 4 then it runs open loop

 

[Prozento]

The video that you posted is mostly used for calibrating the fuel trims not the afr at wot especially if your car runs open loop at wot like me. With the help of the video you can adjust your short term and long term trims and if your can runs open loop at wot and your afr is 9s then if i were you i would decrease ten percent from 3.8 to 5v from your current maf table.
İf you don’t know it runs open or closed loop you can understand it from the short term trims or fuel stat. İf short trims are 0 at wot and fuel stat is 4 then it runs open loop

Thanks for the reply
I am aware that the video focus on fuel trims. On other hand I need some point to begin from to try to fix this issue. Hope this will help, and if not, you will see a new post here soon hehe

 

[CIVICUK]

The video that you posted is mostly used for calibrating the fuel trims not the afr at wot especially if your car runs open loop at wot like me. With the help of the video you can adjust your short term and long term trims and if your can runs open loop at wot and your afr is 9s then if i were you i would decrease ten percent from 3.8 to 5v from your current maf table.
İf you don’t know it runs open or closed loop you can understand it from the short term trims or fuel stat. İf short trims are 0 at wot and fuel stat is 4 then it runs open loop

My car runs in fuel stat 4 at w.o.t which is were mine needs adjusting when i run basemaps. But my question is, if you want to adjust the " fuel trims" would that mean adjusting the rest of the maf scale under 3.8v ? Never really ubderstood this part. ?

 

[kadireren]

My car runs in fuel stat 4 at w.o.t which is were mine needs adjusting when i run basemaps. But my question is, if you want to adjust the " fuel trims" would that mean adjusting the rest of the maf scale under 3.8v ? Never really ubderstood this part. ?

for short term and long term trims --under 3.8v

for afr at WOT above 3.8

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