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Question about Closed Loop Lambda Range

Started by les, November 03, 2020, 06:17:15 AM

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les

I have a 2020 Electra Glide Standard and I'm going to put in an SE 131" Stage IV crate engine.  I just got the Power Vision with the Target Tune Kit.  I plan to install the wide band O2's in the Billet Cat 2-into-1.  I've already received a starter map for the 131" configuration from Dynojet.  I plan to use TT during my 500 mile breakin, before I take it to the local Indy for a full-out tuning session.  They are handy with tuning using the PV.

Unless they tell me otherwise, I'd like to leave the TT and wide bands installed and run closed loop after the tuning session.

The starter map that was provided by Dynojet has the "Closed Loop Lambda Range" attribute set (if I click "Show as Air-Fuel Ratio") to a range of 14.9 (top cell) and 14.4 (bottom cell).  This range seems a bit narrow.  Heck, even narrow band sensors would work in closed loop in this range.  Wouldn't it make more sense to expand this range since I'm planning to leave the wide band O2's in the pipe after the tuning session?

Jamie Long

Target Tune calibrations do not use the Closed Loop Lambda range table, they use the Fuel/Lambda table as absolute.

les

Quote from: Jamie Long on November 03, 2020, 07:28:53 AM
Target Tune calibrations do not use the Closed Loop Lambda range table, they use the Fuel/Lambda table as absolute.

What uses the Closed Loop Lambda Range table?

Coyote


les

Quote from: Coyote on November 03, 2020, 09:48:38 AM
None TT enabled tunes.

Ok, so neither the Power Vision nor the TT uses the Closed Loop Lambda Range table.  I wonder what it's function is.

Coyote

I already told you. It's for non TT enabled tunes. Different settings used for narrow band vs the wide bands.

rbabos

Quote from: les on November 03, 2020, 09:52:39 AM
Quote from: Coyote on November 03, 2020, 09:48:38 AM
None TT enabled tunes.

Ok, so neither the Power Vision nor the TT uses the Closed Loop Lambda Range table.  I wonder what it's function is.
Powervison will use either clb or lambda tables for closed loop stock sensors. For WB sensors, the cal is enabled for TT. AFR or Lambda fuel tables are now used instead. Both NB and WB are closed loop. It just depends on the cal used and the appropriate sensors used for that cal.
Ron

b0fh

that range is for narrowbands, tt uses widebands. apples and coconuts  :bike:

les

Quote from: b0fh on November 03, 2020, 09:22:22 PM
that range is for narrowbands, tt uses widebands. apples and coconuts  :bike:

Ok.  I'm getting closer to understanding.  It's kind of stupid though to have that table because the narrow bands have an inherent range.  So, why confuse the user by putting in a useless table?  Just hard code that range in the software, since "it is what it is".

And thanks to all for your patience.  A lot to learn for me about tuning.

Coyote

Quote from: les on November 04, 2020, 06:38:16 AM

Ok.  I'm getting closer to understanding.  It's kind of stupid though to have that table because the narrow bands have an inherent range.  So, why confuse the user by putting in a useless table?  Just hard code that range in the software, since "it is what it is".


Because you might not want to use all that range. It's never wrong to make software more versatile. You can always leave it alone.

rbabos

Quote from: les on November 04, 2020, 06:38:16 AM
Quote from: b0fh on November 03, 2020, 09:22:22 PM
that range is for narrowbands, tt uses widebands. apples and coconuts  :bike:

Ok.  I'm getting closer to understanding.  It's kind of stupid though to have that table because the narrow bands have an inherent range.  So, why confuse the user by putting in a useless table?  Just hard code that range in the software, since "it is what it is".

And thanks to all for your patience.  A lot to learn for me about tuning.
Range yes but it can be tweaked. For example, even a .2 change in AFR, well within the NB range is a substantial difference.
Ron

les

Quote from: Coyote on November 04, 2020, 07:01:14 AM
Quote from: les on November 04, 2020, 06:38:16 AM

Ok.  I'm getting closer to understanding.  It's kind of stupid though to have that table because the narrow bands have an inherent range.  So, why confuse the user by putting in a useless table?  Just hard code that range in the software, since "it is what it is".


Because you might not want to use all that range. It's never wrong to make software more versatile. You can always leave it alone.

I understand the theoretical flexibility of making everything a editable table, but not understanding what real-life scenario a tuner could show cause for changing that table.  In other words, what performance or runability gain is a tuner trying to achieve by editing that table?  Has any tuner out there actually changed that table?

Also, if that table was hard coded to be from 10.0 - 20.0, it would have the exact same affect.  The narrow bands can't adjust outside of their 14.2 - 15.2 and the same with the wide bands not being able to adjust outside of 10.0 - 20.0.

I guess I'm accustom to software giving the user control of a setting because if a useful functional purpose.  Having a no-op button, so to speak, makes me scratch my head wondering why.

rbabos

Quote from: les on November 05, 2020, 09:48:05 AM
Quote from: Coyote on November 04, 2020, 07:01:14 AM
Quote from: les on November 04, 2020, 06:38:16 AM

Ok.  I'm getting closer to understanding.  It's kind of stupid though to have that table because the narrow bands have an inherent range.  So, why confuse the user by putting in a useless table?  Just hard code that range in the software, since "it is what it is".


Because you might not want to use all that range. It's never wrong to make software more versatile. You can always leave it alone.

I understand the theoretical flexibility of making everything a editable table, but not understanding what real-life scenario a tuner could show cause for changing that table.  In other words, what performance or runability gain is a tuner trying to achieve by editing that table?  Has any tuner out there actually changed that table?

Also, if that table was hard coded to be from 10.0 - 20.0, it would have the exact same affect.  The narrow bands can't adjust outside of their 14.2 - 15.2 and the same with the wide bands not being able to adjust outside of 10.0 - 20.0.

I guess I'm accustom to software giving the user control of a setting because if a useful functional purpose.  Having a no-op button, so to speak, makes me scratch my head wondering why.
Gives you the ability to change the targeted fuel you would desire for conditions. Less so with NB but like I said .2 afr change is very noticeable if there area drivability issues. Example. Most v rod stock cals are mostly 14.7+ afr and run like "Potty mouth" in the low end and run hot. 14.4, it will purr and run cooler in those specific areas of idle and low end reversion areas. Then again, no need to run a richer 14.4 at cruise so 14.68 -14.7 gives a better economy for cruising. This is just an example but you get the point.
Ron

les

Ron, I agree with what you said and how you explained it and how it relates to AFR and VE tables.  However, I'm still not seeing the relation to the Closed loop range table.  For example, let's say a tuner did a dyno tuning and the setup is NB.  The owner of the bike gets the bike home and goes in and changes the values in the closed loop range table to 10.0 - 18.0.  The end result will be no difference.  The owner of the bike could muck with the closed loop table every day of his life and the result will be nothing.

To me it would be like putting a button on the menu bar of Microsoft Word that has no function.  It's just a button to push, and does nothing.  Doesn't change the document, doesn't result in any noticeable function.

Jamie Long

Quote from: les on November 06, 2020, 06:53:19 AM
Ron, I agree with what you said and how you explained it and how it relates to AFR and VE tables.  However, I'm still not seeing the relation to the Closed loop range table.  For example, let's say a tuner did a dyno tuning and the setup is NB.  The owner of the bike gets the bike home and goes in and changes the values in the closed loop range table to 10.0 - 18.0.  The end result will be no difference.  The owner of the bike could muck with the closed loop table every day of his life and the result will be nothing.

To me it would be like putting a button on the menu bar of Microsoft Word that has no function.  It's just a button to push, and does nothing.  Doesn't change the document, doesn't result in any noticeable function.

This is absolutely not correct; assuming the bike has factory narrowband sensors if you switched the closed loop lambda range to .68 - 1.20 that would certainly make a difference, like a huge messed up difference as you would be telling the ECU to look for closed loop far outside where the O2 sensors are linear. The ECU would try to swing the integrator back and forth from way rich to way lean. It would be trying to provide closed loop fuel control at an AF the sensors cannot accurately sample, this is exactly what this table is there to prevent!

The only time this table is NOT used is with a Target Tune or Smart Tune Pro calibration, as these tunes have a patch when you enable the 0-5v wideband sensors that ignores this table.

Jamie Long

Let me explain it this way; the Closed Loop Lambda Range table is there to set the allowable lambda range for O2 feedback. This is typically set about .97 - 1.01 Lambda which is the range the narrowband sensors can accurately sample. If this table diddn't exist the ECM would try to control the AF to whichever value was in the base Air/Fuel - Lambda table regardless of it value even if it was a value the sensor couldn't measure, the ECM would swing the mixture wildly and most cases very quickly set O2 codes.   

les

Thanks for that, Jamie.  Do you know of anyone, ever, who has changed the values in the closed loop range table?