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I use the afr commanded fikter to keep the non-pe stuff
Spook 427 wrote:I cant get it to work, I started to clean up the idle table, I was using the ltft + stft table. Then multiplying by %, and hitting smooth twice. Now the car dies, it barely idles. I was running rich so i was going to clean and re cal my o2 sensor, but what am i doing wrong?
Spook 427 wrote:I cant get it to work, I started to clean up the idle table, I was using the ltft + stft table. Then multiplying by %, and hitting smooth twice. Now the car dies, it barely idles. I was running rich so i was going to clean and re cal my o2 sensor, but what am i doing wrong?
Spook 427 wrote:Should I use the afr error for my idle, and use ltft+stft on low tables
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Edit, you can't use afr error when the car is in closed loop mode.
Screaming for Mercy!! wrote:Quote:
Edit, you can't use afr error when the car is in closed loop mode.
You can't? Why not?
Leafy (Club Jeffie FEA man) wrote:
The fuel trims is perfect for idle, but you're supposed to use add not multiply, just like it was an afr error.
Screaming for Mercy!! wrote:
Leafy (Club Jeffie FEA man) wrote:
Edit, you can't use afr error when the car is in closed loop mode.
You can't? Why not?
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By that logic you would also paste special add for wideband AFR error
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Because the narrowband O2 will be trimming, making your fuel trims look bad and your AFR error look good (commanded 14.7, and the wideband reads 14.7 because the fuel trims).
Wagonwes wrote:
Screaming for Mercy!! wrote:
Leafy (Club Jeffie FEA man) wrote:
Edit, you can't use afr error when the car is in closed loop mode.
You can't? Why not?
Because the narrowband O2 will be trimming, making your fuel trims look bad and your AFR error look good (commanded 14.7, and the wideband reads 14.7 because the fuel trims).
Wagonwes wrote:Leafy (Club Jeffie FEA man) wrote:
The fuel trims is perfect for idle, but you're supposed to use add not multiply, just like it was an afr error.
I have never done this. I am quite sure you are supposed to multiply by percent. The fuel trims are a percentage difference from stoich, not the amount of volumetric efficiency that is being added or subtracted. By that logic you would also paste special add for wideband AFR error, they are essentially the same as far as I am aware. So you would multiply by percent.
See post number 6: http://www.hptuners.com/forum/showthread.php?t=18622&highlight=paste+special+add
Not trying to start anything, but I have always multiplied by percent and have never had issues. If Bill actually is wrong, I have been tuning incorrectly for some time now and had it work out fine for me.
Screaming for Mercy!! wrote:Been there, done that..... Gotta agree!Quote:
Because the narrowband O2 will be trimming, making your fuel trims look bad and your AFR error look good (commanded 14.7, and the wideband reads 14.7 because the fuel trims).
See to me if your tuning from the STFT and LTFT or from the wideband your still trying to achieve the same thing.
I realize the trims are trying to correct things themselves, but it you use the wideband, and smooth it works fine. Works better in my mind. Too many times I have tuned in open loop had everything perfect, then put the car in closed loop and fuel trims are wacked and car runs like @!#$. So since tuning in closed loop using the wideband things work soo much better.
QWK LN2 (P&P Tuning) wrote:LoL.... I'm loving this..... Some of this I even covered in the "how to" I'm working on...
Wagonwes wrote:
Screaming for Mercy!! wrote:
Leafy (Club Jeffie FEA man) wrote:
Edit, you can't use afr error when the car is in closed loop mode.
You can't? Why not?
Because the narrowband O2 will be trimming, making your fuel trims look bad and your AFR error look good (commanded 14.7, and the wideband reads 14.7 because the fuel trims).
If using a WB and the proper histograms, you CAN! I have done it this way for years...
If you are using filters, sure it can be done, didn't say you couldn't. Without filters, it would be incredibly hacked I would think.
Wagonwes wrote:Leafy (Club Jeffie FEA man) wrote:
The fuel trims is perfect for idle, but you're supposed to use add not multiply, just like it was an afr error.
I have never done this. I am quite sure you are supposed to multiply by percent. The fuel trims are a percentage difference from stoich, not the amount of volumetric efficiency that is being added or subtracted. By that logic you would also paste special add for wideband AFR error, they are essentially the same as far as I am aware. So you would multiply by percent.
See post number 6: http://www.hptuners.com/forum/showthread.php?t=18622&highlight=paste+special+add
Not trying to start anything, but I have always multiplied by percent and have never had issues. If Bill actually is wrong, I have been tuning incorrectly for some time now and had it work out fine for me.
Here is one for you guys..... Try it adding, take a screen shot, then UNDO and try it my Multiplying.... Compare and see what you get... It will be damn near identical..... Myself and Joe Rutledge came across this and had a very lenghty discussion on this about a year ago.... Technically, you are supposed to Multiply based on the % error and the Special Paste being a % also... As far as I'm concerned, its a personal choice when it comes to this topic and our sh!tty PCM.....
I was just going to comment the same thing... I was making a little excel table to illustrate (arbitrary values used):
VE.....Wideband AFR Error (percent)....Multiply by Percent ..........Add
50............................ -5............................................47.5.....................45
75........................... 10............................................82.5.....................85
100......................... 18............................................118....................118
125........................ -10............................................112.5................115
150........................ -25............................................112.5................125
You can see that they are all fairly close, especially near 100 percent VE. However in the higher VE numbers there can be a size-able gap that could be fairly problematic in some situations. I understand that I am splitting hairs, but there is a correct way to do things, and technically you are supposed to multiply.
Screaming for Mercy!! wrote:Been there, done that..... Gotta agree!Quote:
Because the narrowband O2 will be trimming, making your fuel trims look bad and your AFR error look good (commanded 14.7, and the wideband reads 14.7 because the fuel trims).
See to me if your tuning from the STFT and LTFT or from the wideband your still trying to achieve the same thing.
I realize the trims are trying to correct things themselves, but it you use the wideband, and smooth it works fine. Works better in my mind. Too many times I have tuned in open loop had everything perfect, then put the car in closed loop and fuel trims are wacked and car runs like @!#$. So since tuning in closed loop using the wideband things work soo much better.
If you are using filters it is a perfectly acceptable way of getting the job done, I agree as well.