Sharktuning experience
Nordschleife Master
Joined: Apr 2003
Posts: 9,601
Likes: 39
From: Abbotsford B.C.
Hello Marti,
In some versions of the software you can control where the NBO2 sensor is active and being used.
Otherwise, the system auto disables that feature when the MAF rate exceeds a set point, or when the WOT switch is engaged.
In some versions of the software you can control where the NBO2 sensor is active and being used.
Otherwise, the system auto disables that feature when the MAF rate exceeds a set point, or when the WOT switch is engaged.
Nordschleife Master
Joined: Jan 2009
Posts: 5,609
Likes: 84
From: MA
The real-time adjustment is the "O2-adjust" value shown in Sharktuner, and the long-term average is saved as an "O2-adaptation" value. (Two values, actually). For example, if the real-time O2-adjust is moving around between say +6 and +14% (i.e. adding an average of 10% more fuel), then the O2-adaptation values will gradually change to +10% and the real-time O2-adjust will then be moving between -4% and +4%. As the MAF ages over time then it tends to read less airflow, and the O2-adaptation value will trend more positive, to the max of +20%.
Outside that shaded area the O2/fuel loop is shut off (i.e. the LH is running open-loop), with the fueling determined by the map values alone (plus O2-adaptation).
Outside that shaded area the O2/fuel loop is shut off (i.e. the LH is running open-loop), with the fueling determined by the map values alone (plus O2-adaptation).
Rennlist Member
Joined: Jan 2008
Posts: 4,076
Likes: 331
From: Friday Harbor, WA
They are global and applied everywhere. The primary purpose is to compensate for aging MAFs which would contribute an error everywhere.
Nordschleife Master
Joined: Jan 2009
Posts: 5,609
Likes: 84
From: MA
They are global and applied everywhere. The primary purpose is to compensate for aging MAFs which would contribute an error everywhere.
It can, yes. The NBo2 sensor only knows stoich (14.7 AFR or whatever), so that's where the cells in the "O2-adjust area" are are going to wind up (with O2-sensor enabled in Sharktuner). And if it takes a big fuel adjustment to get there, then that adjustment-- over time-- becomes part of the adaptation value. In reality this is only an issue for cells where the engine spends time. I excluded the lower-left (high-load/low-RPM) cells but that's not really a concern, because those are transitional (starting off in first gear for example). What's important is that the cruising-down-the-highway cells are all tuned to match the 14.7 AFR that the NBo2 sensor reads.
It can, yes. The NBo2 sensor only knows stoich (14.7 AFR or whatever), so that's where the cells in the "O2-adjust area" are are going to wind up (with O2-sensor enabled in Sharktuner). And if it takes a big fuel adjustment to get there, then that adjustment-- over time-- becomes part of the adaptation value. In reality this is only an issue for cells where the engine spends time. I excluded the lower-left (high-load/low-RPM) cells but that's not really a concern, because those are transitional (starting off in first gear for example). What's important is that the cruising-down-the-highway cells are all tuned to match the 14.7 AFR that the NBo2 sensor reads.
In any case, I think it's underappreciated by the tuning public that the "cruise" map must be tuned to lambda = 1 in the cells in which the o2-loop is ever allowed to operate if one wants to run the o2-adaptation.
Thread Starter
Pro
Joined: May 2011
Posts: 638
Likes: 23
From: Edinburgh, Scotland
I seem to have a fault with the WB02 sensor which I am hoping someone can identify.
It has started to read maximum lean after a short time from start up without changing the map.
Literally the A/F mixture on the ST will look a little subdued around the stoic number, then start fluctuating between rich and stoic before just shooting straight to full lean 18.99.
I observed yesterday that it did this for the first few minutes until the engine had warmed up and then seemed to work fine but today it just registers full lean even after the engine is warmed up. If I stop the engine and restart I get it registering 9 while the engine if off and then with the engine started I get a small fluctuation for a few seconds around stoic before shooting to full lean
Does anyone know what this is?
It has started to read maximum lean after a short time from start up without changing the map.
Literally the A/F mixture on the ST will look a little subdued around the stoic number, then start fluctuating between rich and stoic before just shooting straight to full lean 18.99.
I observed yesterday that it did this for the first few minutes until the engine had warmed up and then seemed to work fine but today it just registers full lean even after the engine is warmed up. If I stop the engine and restart I get it registering 9 while the engine if off and then with the engine started I get a small fluctuation for a few seconds around stoic before shooting to full lean
Does anyone know what this is?
Rennlist Member
Joined: Jun 2005
Posts: 10,569
Likes: 1,027
From: Oman
Marti,
Did you ever run the motor with the WBO2 sensor installed but not powered up by any chance?- I understand they do not like that at all- a shot to nothing as it were [however unlikely].
Did you ever run the motor with the WBO2 sensor installed but not powered up by any chance?- I understand they do not like that at all- a shot to nothing as it were [however unlikely].
Thread Starter
Pro
Joined: May 2011
Posts: 638
Likes: 23
From: Edinburgh, Scotland
I am going to go for a change in the sensor as per Colin's suggestion. If feels electrical to me as there is no change in engine note when the sensor goes to full lean which does not correlate.
Strangely it was working yesterday after revving it a few times so I will see if it clears, maybe clogged or something.
I also took the time to run a CR check while changing the plug leads (they were deteriorating) just to check for any anomalies - all cylinders were 150 psi within about 2 psi of each other so all normal.
Strangely it was working yesterday after revving it a few times so I will see if it clears, maybe clogged or something.
I also took the time to run a CR check while changing the plug leads (they were deteriorating) just to check for any anomalies - all cylinders were 150 psi within about 2 psi of each other so all normal.
Rennlist Member
Joined: Feb 2006
Posts: 3,847
Likes: 558
From: Chicago Bears
Is the engine modified?
Thread Starter
Pro
Joined: May 2011
Posts: 638
Likes: 23
From: Edinburgh, Scotland