Tuning AFM FLOW
Tuning AFM FLOW
In regards to: https://www.hondata.com/help/flashpro/i ... g_fuel.htm
Using the referenced XY graph (at the bottom) as the example, It is stated:
"In this case the AFM is reading approx 15% low, and the first tuning change would be to increase the AFM flow numbers by 15%, across the whole table, and then retest."
To me it seems as 15% high (if "0" is neutral)?
Can you confirm?
I attached a XY graph from my very first datalog. I'm not going to adjust anything until further logs but want to understand.
Thank you
Using the referenced XY graph (at the bottom) as the example, It is stated:
"In this case the AFM is reading approx 15% low, and the first tuning change would be to increase the AFM flow numbers by 15%, across the whole table, and then retest."
To me it seems as 15% high (if "0" is neutral)?
Can you confirm?
I attached a XY graph from my very first datalog. I'm not going to adjust anything until further logs but want to understand.
Thank you
 Attachments

 JJCivic AFM XY graph  very 1st run.PNG (24.93 KiB) Viewed 840 times
Re: Tuning AFM FLOW
And 30 min drive home:
 Attachments

 JJCivic AFM XY graph  2nd run  30 minute city drive.PNG (29.78 KiB) Viewed 837 times
Re: Tuning AFM FLOW
Hi JJ!
Based in what I researched about Short Trim last month, I think I can answer this one for you!
First, you need to know basically that S. Trim is a "corrector" of your AFR. Based in the readings of your lambda sensor, It indicates If mixture is reach or lean.
Let us supose that your car is running LEAN 5% in all rev range. This information will be sent to the ECU, and the S.Trim Will INCREASE AFR by 5%, by putting a little bit more fuel.
S.Trim will correct your AFR by a +5%.
That is why lean AFR shows a positive S.Trim, and rich AFR shows a negative S.Trim. Got It?
With that information, and looking in your graphs, It is easy to see that your 2.5 k rpm has a perfect AFR.
From 1k to 2.2k you are running reach by 5 to 7 %.
And from 3k and above you get richer too...
I think that this is the point. Understanding Short Trim.
But shortly somebody will correct me, If I am wrong.
Based in what I researched about Short Trim last month, I think I can answer this one for you!
First, you need to know basically that S. Trim is a "corrector" of your AFR. Based in the readings of your lambda sensor, It indicates If mixture is reach or lean.
Let us supose that your car is running LEAN 5% in all rev range. This information will be sent to the ECU, and the S.Trim Will INCREASE AFR by 5%, by putting a little bit more fuel.
S.Trim will correct your AFR by a +5%.
That is why lean AFR shows a positive S.Trim, and rich AFR shows a negative S.Trim. Got It?
With that information, and looking in your graphs, It is easy to see that your 2.5 k rpm has a perfect AFR.
From 1k to 2.2k you are running reach by 5 to 7 %.
And from 3k and above you get richer too...
I think that this is the point. Understanding Short Trim.
But shortly somebody will correct me, If I am wrong.
Re: Tuning AFM FLOW
Sorry!!!
Where you read "k rpm", change It by "Volt". Like, 2.5 k rpm is 2.5 V.
My bad.
Where you read "k rpm", change It by "Volt". Like, 2.5 k rpm is 2.5 V.
My bad.
Re: Tuning AFM FLOW
And just to confirm :)
Using the above info, "From 1k to 2.2k you are running reach by 5 to 7 %."
I could adjust the highlighted Mass flow #'s in the example here:
Re: Tuning AFM FLOW
Hi JJ!
Listen, first of all I want you to know that I still don't have a FlasPro, ok! But I really like Graphs.
The answer to you question above is yes, in my point of view. This would be my starting point, if your car was mine.
But, I realized that your second graph is really better and smoother then the first one. It tells me that you took more time running the car to build that graph. So, for me, it is a very nice start. Much better than the first one. And it is much easier to see the gaps.
So, I took some time here, and build up to you a full scale that, in my opinion, you could be using on your AFM tunning. I took a ruler, and rebuild your graph, putting points every 0,1 V.
Therefore, If I were you, and your car was mine, I would start with this adjustments.
. . Voltage . . . Mass flow
1,05 up to 1,60 = 5%
1,68 up to 1,99 = 7%
2,03 up to 2,15 = 5%
2,19 up to 2,23 = 4%
2,30 up to 2,38 = 2%
2,46 up to 2,77 = 0%
2,85 up to 3,71 = 2%
3,79 up to 4,34 = 3%
First observation: It is remarkable that the graph has A LOT of points from 1,10 to 2,6 Volts. So, it is much more precise to tell the corrections.
Second observation: from 3 volts and above, there are not so much points. So I was a bit more conservative on the corrections.
Please save all your starting numbers before the change!!!!!
Finally, I want to reinforce to you that this corrections that I proposed to you is what I would start doing, if your car was mine.
I would upload this new numbers, and take another 30 minutes ride again. And in the end build another graph. Warm up your car before starting datalog. Let the ECU get used to the new numbers.
If you get a little afraid doing all this changes at once, you can start doing only one or two lines of the table above. Make a shorter ride, like, 15 minutes, and take a look on the new graph... It is better to change the part that you use more on a ride, the low voltage part.
I am really excited to see this new graph!!!
And I hope that it helps putting a better AF in your car!!!!
Listen, first of all I want you to know that I still don't have a FlasPro, ok! But I really like Graphs.
The answer to you question above is yes, in my point of view. This would be my starting point, if your car was mine.
But, I realized that your second graph is really better and smoother then the first one. It tells me that you took more time running the car to build that graph. So, for me, it is a very nice start. Much better than the first one. And it is much easier to see the gaps.
So, I took some time here, and build up to you a full scale that, in my opinion, you could be using on your AFM tunning. I took a ruler, and rebuild your graph, putting points every 0,1 V.
Therefore, If I were you, and your car was mine, I would start with this adjustments.
. . Voltage . . . Mass flow
1,05 up to 1,60 = 5%
1,68 up to 1,99 = 7%
2,03 up to 2,15 = 5%
2,19 up to 2,23 = 4%
2,30 up to 2,38 = 2%
2,46 up to 2,77 = 0%
2,85 up to 3,71 = 2%
3,79 up to 4,34 = 3%
First observation: It is remarkable that the graph has A LOT of points from 1,10 to 2,6 Volts. So, it is much more precise to tell the corrections.
Second observation: from 3 volts and above, there are not so much points. So I was a bit more conservative on the corrections.
Please save all your starting numbers before the change!!!!!
Finally, I want to reinforce to you that this corrections that I proposed to you is what I would start doing, if your car was mine.
I would upload this new numbers, and take another 30 minutes ride again. And in the end build another graph. Warm up your car before starting datalog. Let the ECU get used to the new numbers.
If you get a little afraid doing all this changes at once, you can start doing only one or two lines of the table above. Make a shorter ride, like, 15 minutes, and take a look on the new graph... It is better to change the part that you use more on a ride, the low voltage part.
I am really excited to see this new graph!!!
And I hope that it helps putting a better AF in your car!!!!
Re: Tuning AFM FLOW
DarkCiv,
Very much appreciated. Thanks for taking the time to look at this.
Thank you.
Very much appreciated. Thanks for taking the time to look at this.
Thank you.