The 2014+ tunes I have seen have a closed loop range of 14.2 - 15.0. The 2014 + models have heated O2 sensors.
Ya... Sounds about right from what I've seen. Don't know why they would be setting things above 14.6. But, if memory serves, I saw a few cells in a stock (2014+) AFR table that did just that. My only interest would be how much richer could they go and maintain closed loop. That's why I didn't mention the other end.
I've noticed if I load a tune with 14.6 AFR cells and then load a tune to compare, it seems the compare tune also gets the circles around the AFR values that are not 14.6 at least where the originally loaded tune has AFR of 14.6
The top AFR table is from a 2014+ tune that is lambda based, hence the "Show as AFR for gasoline at 14.7" for lambda of 1.0.
If you have the early Sportster (2007-2013) ECM / Software level 176 and you want to run closed loop but want a richer AFR look at the closed loop bias tables Front / rear.
The PowerVision Auto Tune with narrow band O2 sensors sets these tables to .700 during Auto Tune with the entire AFR table set to 14.6 (it also pulls 4 degrees of spark timing)
The stock tune has these set to .440 (.450 would actually be 14.68)
to get 14.5 use a bias of ~.768 with the AFR table set to 14.6
to get 14.4 use a bias of ~.785
to get 14.3 use a bias of ~.794
Since your AFR table still has 14.6 you should still be in closed loop (as long as you also have closed loop enabled in the limits and settings)
The HD Pro Super tuner software shows you can use a max of .798 and a min of .409 if you want to run leaner for gas mileage.
These settings would only apply to ethanol free gasoline, if you are running E10 with the AFR set to 14.6 you would actually be closer to 14.0 - 14.1 AFR at .450 closed loop bias.
I consider 14.6 to be like a lambda value of 1.0
Staying in closed loop with Adaptive control allows the use of different gas blends with different Stoich ratios.
The tune I got from Fuelmoto has the CLB set to 700 and a stock AFR map and after reading your post it has been driving me nuts. I was told 700 is about 14.3. Did some reading and your are pretty well spot on. The tune I got from Dyno jet had me running in open loop all the time with basically all the stock AFR 14.6 settings set to 14.5. Then seeing some of these dyno tuned maps that seems to me are kinda nuts especially the one set to 13.8 across the board. I looked all over the net trying to find some reading to help me understand the CLB. I am a little OCD I have to have a least a basic to good understanding of what I am doing. I cant just load a tune and go especially when I see the different approaches that DJ and FM went with the tunes and both are supposed to be dyno'd sportys with my setup. I am still try to get a good understanding of:
1. running open loop all the time, what this does to the O2 sensors, and the effects of different gas blends etc.
2. how the CLB actually works (I am getting there albeit slowly).
I searched all over the web and I finally downloaded a Master tune users manual that had some good stuff. I will post it maybe it will help someone else with the same questions I have.
The Closed Loop Bias Table
The actual AFR that is maintained in closed-loop mode is set by the Closed Loop Bias table. The closed loop bias table is used to adjust the closed loop AFR, typically to run the mixture a bit richer than the table value of 14.6 would indicate. Setting the value in this table to 450 mV will result in a closed loop AFR of 14.68; increasing the value will give a richer mixture and decreasing the value will give a leaner mixture. In the following example, the offset of 645 mV will target a AFR of approximately 14.64.
Note: When a value other than 450 mV is entered into the CLB table it will create an offset in any table controlling AFR. The AFR offset is determined using the O2 calculator. For example, at 780 mV the AFR offset is (14.68 – 14.43) = 0.25 (richer) . For all tables that show AFR, the actual value is 0.25 less than what is displayed on the table. This assumes that the VE table has been correctly calibrated.
Key Point: Closed-loop operation attempts to keep the O2 voltage at an average value determined by the CLB table, Figure 3-16. This equates to keeping the free oxygen in the exhaust at some particular value. What the actual AFR is at this point depends on the fuel blend being burned!
When adjusting the CLB table, the minimum resolution is 20 mV. For this reason, along with the shape of the lambda curve, it is not possible to accurately control the AFR outside of a narrow region, from about 250 to 800 mV sensor voltage.
The normal range for the CLB setting is between 250 and 675 mV. TTS does not recommend setting the CLB voltage above 800 mV, as over time O2 sensors degrade and loose the ability to respond at their voltage extremes.
Note: Today’s fuel blends have a stoichiometric AFR varying from 14.28 to 14.68! Closed loop operation helps compensate for this variation.
The limitation of the 2007-2013 Sportster ECM/Maps of having to have 14.6 to 1 AFR to run in closed loop makes things strange if you are actually running a gasoline with 10% ethanol. 10% ethanol adds about 4% additional oxygen in the fuel.
If you have the AFR set to 14.6, with the ECU in closed loop, the ECU will use the O2 voltages to compensate for the additional 4% O2 and add fuel, with 10% ethanol you will actually running at about 14.1 to 1.
If you change the AFR to 14.5 or 14.4 you take the ECU OUT of closed loop and if you are running E10 you would now be running about 0.4 or 0.3 lean.
The 2014+ Sportsters use a Lambda based tune, heated O2 sensors to give a little wider range of control (especially at low engine speeds). The ECU with the updated software level will run in closed loop in Lambda range of 0.964 to 1.023 which is equal to an AFR of about 14.2 to 15.0.
At Idle and cruise at low loads the engine will run fine at 15.0 to 1 (Lambda 1.023).
I have run my 2013 Sportster with the idle AFR set at 15.0 to 1 (both 30 and 40 kPa map columns)
Here is the technical info for Sunoco GT100 100 octane unleaded race gas-
Another interesting SAE article I found, max engine temp is at 14.6 to 1, leaner actually decreases the engine temp-
http://papers.sae.org/1999-01-0284/ In-cylinder heat flux and temperature measurements were obtained in an air-cooled four-stroke utility engine for a range of air-fuel ratios. For these measurements, the magnitude of the integrated heat flux peaked at the stoichiometric air-fuel ratio, with an approximately linear decrease on either side of stoichiometric. Advancing the spark generally increased the magnitude of the integrated heat flux.
Burn speed and AFR- http://www.innovatemotorsports.com/resources/myths.php
The burning speed is also dependent on the air-fuel-ratio. At about 12.5 to 13 air-fuel-ratio the mixture burns fastest. A leaner mixture than that burns slower. A richer mixture also burns slower
The limitation of the 2007-2013 Sportster ECM/Maps of having to have 14.6 to 1 AFR to run in closed loop makes things strange if you are actually running a gasoline with 10% ethanol. 10% ethanol adds about 4% additional oxygen in the fuel.
If you have the AFR set to 14.6, with the ECU in closed loop, the ECU will use the O2 voltages to compensate for the additional 4% O2 and add fuel, with 10% ethanol you will actually running at about 14.1 to 1.
If you change the AFR to 14.5 or 14.4 you take the ECU OUT of closed loop and if you are running E10 you would now be running about 0.4 or 0.3 lean.
Yeah thats why I am running closed loop.
The 2014+ Sportsters use a Lambda based tune, heated O2 sensors to give a little wider range of control (especially at low engine speeds). The ECU with the updated software level will run in closed loop in Lambda range of 0.964 to 1.023 which is equal to an AFR of about 14.2 to 15.0.
At Idle and cruise at low loads the engine will run fine at 15.0 to 1 (Lambda 1.023).
I have run my 2013 Sportster with the idle AFR set at 15.0 to 1 (both 30 and 40 kPa map columns)
I have been looking at that strategy on the 2014+. Lots of difference especially at low load and idle. Its got me thinking.
Here is the technical info for Sunoco GT100 100 octane unleaded race gas-
Another interesting SAE article I found, max engine temp is at 14.6 to 1, leaner actually decreases the engine temp-
http://papers.sae.org/1999-01-0284/ In-cylinder heat flux and temperature measurements were obtained in an air-cooled four-stroke utility engine for a range of air-fuel ratios. For these measurements, the magnitude of the integrated heat flux peaked at the stoichiometric air-fuel ratio, with an approximately linear decrease on either side of stoichiometric. Advancing the spark generally increased the magnitude of the integrated heat flux.
Burn speed and AFR- http://www.innovatemotorsports.com/resources/myths.php
The burning speed is also dependent on the air-fuel-ratio. At about 12.5 to 13 air-fuel-ratio the mixture burns fastest. A leaner mixture than that burns slower. A richer mixture also burns slower
Interesting. In the areas of my AFR (low rpm, low-high map) I set my AFR to 13.8-14.1 and when I drop to these areas my temp drops 10-20 deg. I'm running closed loop 80-90% of the time with a CLB of 750. With the PV I ran my gauges at rpm, eng. temp, map KPa, and AFR. So I pretty much know where I am on the AFR table. The hottest I got in closed loop was 384 deg and droped to the lowest of 358 when I dropped to low rpm (off throttle) that surprised the hell out of me. I am really pleased now.
But I am thinking of making a AFR table for cooler weather just for the fun of it. I only run my gauges for 30 mi or so then put the PV up and just enjoy the ride. I caught my self looking at it to damn much.
The limitation of the 2007-2013 Sportster ECM/Maps of having to have 14.6 to 1 AFR to run in closed loop makes things strange if you are actually running a gasoline with 10% ethanol. 10% ethanol adds about 4% additional oxygen in the fuel.
If you have the AFR set to 14.6, with the ECU in closed loop, the ECU will use the O2 voltages to compensate for the additional 4% O2 and add fuel, with 10% ethanol you will actually running at about 14.1 to 1.
If you change the AFR to 14.5 or 14.4 you take the ECU OUT of closed loop and if you are running E10 you would now be running about 0.4 or 0.3 lean.
The 2014+ Sportsters use a Lambda based tune, heated O2 sensors to give a little wider range of control (especially at low engine speeds). The ECU with the updated software level will run in closed loop in Lambda range of 0.964 to 1.023 which is equal to an AFR of about 14.2 to 15.0.
At Idle and cruise at low loads the engine will run fine at 15.0 to 1 (Lambda 1.023).
I have run my 2013 Sportster with the idle AFR set at 15.0 to 1 (both 30 and 40 kPa map columns)
Here is the technical info for Sunoco GT100 100 octane unleaded race gas-
Another interesting SAE article I found, max engine temp is at 14.6 to 1, leaner actually decreases the engine temp-
http://papers.sae.org/1999-01-0284/ In-cylinder heat flux and temperature measurements were obtained in an air-cooled four-stroke utility engine for a range of air-fuel ratios. For these measurements, the magnitude of the integrated heat flux peaked at the stoichiometric air-fuel ratio, with an approximately linear decrease on either side of stoichiometric. Advancing the spark generally increased the magnitude of the integrated heat flux.
Burn speed and AFR- http://www.innovatemotorsports.com/resources/myths.php
The burning speed is also dependent on the air-fuel-ratio. At about 12.5 to 13 air-fuel-ratio the mixture burns fastest. A leaner mixture than that burns slower. A richer mixture also burns slower
Very interesting info, would you mind posting your AFR table?
Thanks
Air/Fuel (A/F) Ratios of Common Fuels
Fuel A/F Lambda (λ)
Pure Gasoline Stoichiometric 14.7 1.000
Pure Gasoline Max Power Rich 12.5 0.8503
Pure Gasoline Max Power Lean 13.2 0.900
E10 Stoichiometric 14.1 1.000
E10 Max Power Rich 12.0 0.8523
E10 Max Power Lean 12.7 0.9020
AFR Table: (the 12.7 and 12.0 at 90 and 100 kPa are because I usually run E10) The stock 12.5 doesn't seem to make much difference to me, I seldom get to 100 kPa
Closed Loop Bias Table: (the 100 MAP column will not really be used since I will be in "open loop")
I've noticed if I load a tune with 14.6 AFR cells and then load a tune to compare, it seems the compare tune also gets the circles around the AFR values that are not 14.6 at least where the originally loaded tune has AFR of 14.6
The top AFR table is from a 2014+ tune that is lambda based, hence the "Show as AFR for gasoline at 14.7" for lambda of 1.0.
With software 374 it will circle any value between 14.2 and 15.0.
The values circled are closed loop values to make it easier to see them when comparing tunes.
08-21-2017, 08:11 AM
