Jamie, Is there any real advantage to running a bike in "closed-loop" other than EPA compliance/fuel mileage? Are the other sensors pretty good at keeping the running AFR at the AFR set in the table when the O2 sensors are turned off? My biks sure seems to run better in open-loop with the O2 sensors turned off. Do you recommend 14.5 AFR in all areas that were previously 14.6? Thanks.

 

You're at 14.4 which is richer than 14.5, so you're good.

 

Your 2010 Touring uses a Lambda based calibration, the software simply lets you convert it to AFR. To enable closed loop on Lambda based calibrations it is required that you have Lambda .98-1.02 in your Fuel table (an AFR equivelent of 14.4-15.0) Lambda based calibrations are easy to work with as this value is absolute regardless of fuel

"AFR based" calibrations use 14.6 as the switch for closed loop and you then use the Bias table to choose the O2 sensor reference voltage the integrator uses as it toggles from rich/lean. The image below is a chart that references O2 voltage vs. AFR

 

That is is pretty broad question, it really comes down to the bike model, engine/exhaust/intake modifications, and the specific calibration you are using. On your Sportster we find many times the bike run better with an open loop calibration as the O2 integration is constantly hunting and overshooting it requirements. On the other hand many Twin Cam models run very well with closed loop calibrations, especially Level 9 and Level 44 cals that are RPM X MAP based

 

Yes...my Lambda setting (2010 SE Ultra) is .98 (AFR 14.4) so I'm able to tune in closed loop at .98 which I assume is allowing slightly richer tuning using the stock O2 sensors.

BTW what is the point of narrow band O2 sensors anyways? Is it just a cost savings issue? Even from the factory the stock NB sensors can't accomodate higher loads/RPMs, so why wouldn't a company like HD properly equip their bikes with an O2 sensor that can accomodate the full operating range of the engine it's measuring, even in stock form?

 

A narrowband sensor allows the system to accurately control the mixture when set at/near stoich which includes all of the lower load and cruise areas. The higher load, upper RPM and WOT areas are calibrated to a richer mixture as needed. The Delphi ECM is actually a very basic design by todays standards, a simple answer to your question would be that with the factory components in place the fuel delivery is accurate enough to control with a NBO2 sensor, that is all they really need

 

Is there any chance that in future software these changes will be taken care of automatically in the software? Maybe with logging options?

Michael

 

As Jamie was saying, Harley is trying to hit EPA Mandated 14.6 and the narrow band sensors do an excellent job at 14.6 so nothing else is needed.

 

You can make these changes in the software now but open loop vs closed loop or 14.6 versus some other value is a choice to be made by the tuner. The software allows you to make the changes and data collection and log tuner give you the tools and data to make those choices.

 

Thanks for your input Jamie. My sportster does do a lot of hunting/surging in closed-loop and has since it was new/stock. I really prefer an open-loop only map, but just want to make sure the bike will still be able to hit its AFR targets wtihout the O2 sensors in the loop.

Another question. Is the relationship between VE and AFR a linear relationship? For example, if I increase my VE vlaues in a given area by a value of 5, approximately what will the increase in AFR be in these areas?