Page 1 of 2

AF Corrected value seems off

Posted: Thu Dec 10, 2009 10:36 am
by Gernby
Would you please add another item to the "wish list" for enhancements in FlashPro Manager to alter the AF correction? I don't think my AFR values are nearly as lean as the FlashPro Manager says. I plan to have another O2 sensor bung installed in my exhaust so I can log it with my LM-1, but I'd like to be able to adjust the correction when I do.

Posted: Thu Dec 10, 2009 2:18 pm
by nunoctr
many users of FP have wideband sensors and say that the afr correct is almost the same as the wideband (0.1/0.2 error). So probably it's your stock sensor that is not good.

Posted: Thu Dec 10, 2009 3:12 pm
by Gernby
nunoctr wrote:many users of FP have wideband sensors and say that the afr correct is almost the same as the wideband (0.1/0.2 error). So probably it's your stock sensor that is not good.
I agree that is a possibility, but my AF corrected is reading low 14's at WOT with the stock tune and a nearly stock car (CAI). If it was really that lean, I would expect some knock counts, but I'm not getting any.

My S2000 only has 9500 miles on it, so I wouldn't see any reason for it to be bad.

Posted: Thu Dec 10, 2009 3:35 pm
by Spunkster
Knock is mostly from ignition timing and not fueling.

Posted: Thu Dec 10, 2009 5:59 pm
by Gernby
Spunkster wrote:Knock is mostly from ignition timing and not fueling.
Lean conditions don't cause knock?

Posted: Fri Dec 11, 2009 10:19 am
by soxfan143
Gernby wrote:
Spunkster wrote:Knock is mostly from ignition timing and not fueling.
Lean conditions don't cause knock?
He is assuming that your AFRs are where they need to be. But yes, a lean condition will cause knock. But if your AFRs are good then ignition is the cause of your knock.

Posted: Fri Dec 11, 2009 6:57 pm
by Gernby
soxfan143 wrote:
Gernby wrote:
Spunkster wrote:Knock is mostly from ignition timing and not fueling.
Lean conditions don't cause knock?
He is assuming that your AFRs are where they need to be. But yes, a lean condition will cause knock. But if your AFRs are good then ignition is the cause of your knock.
That would be a poor assumption. I've tuned my fuel maps to have an AF Corrected value at 14.3:1 at WOT throughout the whole RPM range, and am getting better power with no knock count than when I tuned it for 13.5:1.

Re: AF Corrected value seems off

Posted: Fri Dec 11, 2009 9:06 pm
by civicRSA
Gernby wrote:Would you please add another item to the "wish list" for enhancements in FlashPro Manager to alter the AF correction? I don't think my AFR values are nearly as lean as the FlashPro Manager says. I plan to have another O2 sensor bung installed in my exhaust so I can log it with my LM-1, but I'd like to be able to adjust the correction when I do.
I have a similar problem. I'm using my stock wideband to tune. My AF will not go lower than 13.6 no matter how much fuel I add. On the dyno flashpro will say the AF is 14:1 but dyno will say 12:1 my vehicle also has low mileage but I suspect it is my O2 sensor so I have ordered a new one.

Posted: Mon Jan 25, 2010 12:55 pm
by Gernby
I installed my wideband O2 over the weekend (Innovate Motorsports LM-1) in a bung just inches away from the stock primary sensor in the header. As I suspected it would, the AF reading that I'm getting from the LM-1 is very close to the uncorrected AF value in the datalog. The "corrected" value is reading very lean.

Image

Image

Posted: Tue Jan 26, 2010 8:12 am
by Hondata
The correction we use was consistent over several vehicles using a wideband next to the stock primary o2 sensor.

Posted: Tue Jan 26, 2010 9:14 am
by Gernby
Hondata wrote:The correction we use was consistent over several vehicles using a wideband next to the stock primary o2 sensor.
I don't understand your point. Are you saying my results are invalid? My wideband sensor has very few miles on it, since I only use it to tune, and I did a free air calibration before installing it. I can't think of any reason to ignore these results.

What were the vehicles you used? Were any of them '08 AP2's? I really think the correction needs to be adjustable in the software.

Posted: Tue Jan 26, 2010 10:27 am
by Hondata
My point is that there are three vehicles, two are which produce the same results. A larger sample size needs to be made.

We'll add the correction to the software at some point.

Posted: Sat Jan 30, 2010 8:04 pm
by thesilverbullet
Hondata wrote:My point is that there are three vehicles, two are which produce the same results. A larger sample size needs to be made.

We'll add the correction to the software at some point.

were these three cars civics or s2000s? according to your help files the civic was used to determine the af corr. did you also test af on s2k or just assumed it would have the same results as civics...

Posted: Sun Jan 31, 2010 6:56 pm
by Hondata
S2000s of course. The Civic has a different correction.

Re: AF Corrected value seems off

Posted: Wed Dec 10, 2014 1:30 am
by shind3
So it's been 4 years. Has a larger sample size been analyzed? Can I rely on my stock sensor if using 'AF corrected' to tune? I installed a new OEM sensor a couple thousand miles ago.