Power Vision Information Thread
Cruiser
Joined: Mar 2009
Posts: 228
Likes: 0
From: Texas
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.
Thread Starter
|
Extreme HDF Member
Joined: Sep 2005
Posts: 11,615
Likes: 50
From: Baton Rouge, LA
You're at 14.4 which is richer than 14.5, so you're good.
"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
__________________
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
Jamie Long / Fuel Moto USA
The USA's Leader V-Twin EFI & Performance www.fuelmotousa.com
Contact 920-423-3309
Email jamie@fuelmotousa.com
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.
Member
Joined: Jul 2009
Posts: 4,310
Likes: 1,079
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
"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
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?
Last edited by Heatwave; Sep 19, 2011 at 10:17 PM.
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?
Last edited by fuelmoto; Sep 19, 2011 at 11:46 PM.
Road Captain
Joined: Mar 2011
Posts: 627
Likes: 1
From: Oklahoma
Michael
Road Warrior
Joined: Jan 2008
Posts: 1,549
Likes: 18
From: Upstate SC
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?
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
6 Weirdest Harley-Davidsons Ever Sold to the Public
Verdad Gallardo
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
Road Warrior
Joined: Jan 2008
Posts: 1,549
Likes: 18
From: Upstate SC
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.
Cruiser
Joined: Mar 2009
Posts: 228
Likes: 0
From: Texas
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
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?