lawdog
Well-known member
As we all know our bikes come lean from the factory for emissions. I mean really lean, headers sometimes glow at idle lean. So here are some options to tune your Buell for increased power.
I have a 2009 XB12R and ECMSpy does not work for it. Tried it, doesn’t work. Plus I am not of fan of tuning with ECMSpy and here is why.
Factory bikes use the narrowband O2 sensor to tune for 14.7 AFR (air fuel ratio) in closed loop. The O2 sensor switches back and forth to read rich or lean from 14.7 AFR. The problem here in lies is 14.7 AFR is not the best AFR ratio. To tune for maximum torque a tuner generally shoots for 13.5 AFR. (higher the number the richer the mixture). For WOT 12.5 – 12.8 AFR is for maximum power. 14.7 AFR is called stoich where the fuel and air burn with the least emissions. Leaner the 14.7 AFR (>14.7) produces better fuel economy for cars but is not good for air cooled bikes. Most Harley tuners shoot for the 12-14 AFR range depending on RPM and TPS for our bikes. Air cooled bikes benefit from a richer mixture to reduce engine temps and provide for increased power. So to summarize, 12-13 AFR is richer for more power, 14.7 AFR is EPA happy emissions, and 15-16 APR is leaner for better fuel economy.
So now that we know what AFR we want how do we get there? Some very smart people created ECMSpy to tune our Buells. ECMSpy allows you to tweak the fuel and timing maps. The problem I see with ECMSpy is that you are still tuning for 14.7 AFR which in my opinion is still too lean. You are leaving power on the table so to speak. While ECMSpy is a great program, it works, and many people are happy with it. But there is room to increase power by running a richer AFR. If you attempt to tune for any other AFR, the computer in learning mode will apply a global correction in an attempt to bring the AFR back to 14.7. So thus you are stuck with the stock narrowband O2 sensor.
The next option is to get a copy of the Race ECM and either install the Race ECM itself or get a copy of the maps and paste the maps to upload into your ECM. It’s a one size fits all approach and works great for some and not so great for others. If you have the same exhaust and intake as the Race ECM it should get you a decent tune. The tune can be uploaded with ECMSpy and Microsoft Excel or Ohio Sport Bike Software. The drawback with the Race ECM is you are still running 14.7 AFR with the O2 sensors which is my opinion is still too lean for an air cooled motor.
Next option is to modify the O2 sensor or fuel injectors. Basically trick the computer it thinks it is running leaner. The O2 sensor will read rich but you modify the signal so the computer will think its reading 14.7 AFR. Problem with this approach is a factory O2 sensor only switches back and forth from 14.7 AFR. Once you stray from that AFR then it no longer reads accurate. There are simple Ebay units with a high, medium, and low RPM pots to tune it or expensive Power Commanders that use this system. Some alter the O2 signal while others alter the fuel injector signal. There is a post on here recently about an individual who is happy with this system. Best approach would be to put the bike on a Dyno to tune it. Some have reported sucess using a wideband O2 sensor in place of the NB stock sensor and slowing down the signal so the sotck PCM can read it.
So the next option is Ohio Sport Bike. I have played with their program a little bit and I like it. Their approach is to turn off the O2 sensor so you can tune for the AFR you desire. A smart approach. Problem with this method is how do you tune it. Some say shut the O2 off and jog the global maps richer a few percent. While this will bump up the AFR richer you have no idea how richer. Unfortunately OSB does not have any pre-tuned maps for the XB12R so you are on your own to tune it.
In my opinion the best approach is to either get a Wideband O2 sensor and do your own logging or put the bike on a dyno with a wideband and 5 gas analyzer. With the OSB software or ECMSpy and Excel you can turn off thestock O2 and create your maps with the AFR you want and upload them to your bike. While OSB is easier it is also more expensive. ECMSpy is free but you have to use Excel to modify the maps which can be cumbersome. The most important thing to remember is that V-twins are unusual motors and you should tune each cylinder separately. This means welding a bung on the front pipe (pre 2010 models) so you can accurately tune it. A royal pain but it is the best way to tune each cylinder individually for maximum power. We all know the front cylinder runs cooler so its important to properly tune each cylinder with a wideband. Some will arbitrarily increase the front cylinder by a set amount but you are really shooting in the dark.
The best on the market is self-tuning. The idea behind self tuning is to place a wideband O2 sensor in the exhaust and have a controller that adjusts the maps. Where as before you had to drive around with a wideband, log the runs, then adjust the maps, repeat as needed till you dialed in to your AFR. Now you tell the controller what AFR you want and it tunes the maps for it. A great invention but of course costs more money then you doing the work itself. Look at Twin-tec for more information.
The last option is to find somebody who has tuned their maps and use there maps. While this will work, its not perfect. Every bike is different and every bike should be tuned individually. If I ever get motivated enough to buy a wideband and tune my bike properly I will be more then happy to share my maps. Just don’t hold your breath as I don’t plan on doing this for a while.
I have a 2009 XB12R and ECMSpy does not work for it. Tried it, doesn’t work. Plus I am not of fan of tuning with ECMSpy and here is why.
Factory bikes use the narrowband O2 sensor to tune for 14.7 AFR (air fuel ratio) in closed loop. The O2 sensor switches back and forth to read rich or lean from 14.7 AFR. The problem here in lies is 14.7 AFR is not the best AFR ratio. To tune for maximum torque a tuner generally shoots for 13.5 AFR. (higher the number the richer the mixture). For WOT 12.5 – 12.8 AFR is for maximum power. 14.7 AFR is called stoich where the fuel and air burn with the least emissions. Leaner the 14.7 AFR (>14.7) produces better fuel economy for cars but is not good for air cooled bikes. Most Harley tuners shoot for the 12-14 AFR range depending on RPM and TPS for our bikes. Air cooled bikes benefit from a richer mixture to reduce engine temps and provide for increased power. So to summarize, 12-13 AFR is richer for more power, 14.7 AFR is EPA happy emissions, and 15-16 APR is leaner for better fuel economy.
So now that we know what AFR we want how do we get there? Some very smart people created ECMSpy to tune our Buells. ECMSpy allows you to tweak the fuel and timing maps. The problem I see with ECMSpy is that you are still tuning for 14.7 AFR which in my opinion is still too lean. You are leaving power on the table so to speak. While ECMSpy is a great program, it works, and many people are happy with it. But there is room to increase power by running a richer AFR. If you attempt to tune for any other AFR, the computer in learning mode will apply a global correction in an attempt to bring the AFR back to 14.7. So thus you are stuck with the stock narrowband O2 sensor.
The next option is to get a copy of the Race ECM and either install the Race ECM itself or get a copy of the maps and paste the maps to upload into your ECM. It’s a one size fits all approach and works great for some and not so great for others. If you have the same exhaust and intake as the Race ECM it should get you a decent tune. The tune can be uploaded with ECMSpy and Microsoft Excel or Ohio Sport Bike Software. The drawback with the Race ECM is you are still running 14.7 AFR with the O2 sensors which is my opinion is still too lean for an air cooled motor.
Next option is to modify the O2 sensor or fuel injectors. Basically trick the computer it thinks it is running leaner. The O2 sensor will read rich but you modify the signal so the computer will think its reading 14.7 AFR. Problem with this approach is a factory O2 sensor only switches back and forth from 14.7 AFR. Once you stray from that AFR then it no longer reads accurate. There are simple Ebay units with a high, medium, and low RPM pots to tune it or expensive Power Commanders that use this system. Some alter the O2 signal while others alter the fuel injector signal. There is a post on here recently about an individual who is happy with this system. Best approach would be to put the bike on a Dyno to tune it. Some have reported sucess using a wideband O2 sensor in place of the NB stock sensor and slowing down the signal so the sotck PCM can read it.
So the next option is Ohio Sport Bike. I have played with their program a little bit and I like it. Their approach is to turn off the O2 sensor so you can tune for the AFR you desire. A smart approach. Problem with this method is how do you tune it. Some say shut the O2 off and jog the global maps richer a few percent. While this will bump up the AFR richer you have no idea how richer. Unfortunately OSB does not have any pre-tuned maps for the XB12R so you are on your own to tune it.
In my opinion the best approach is to either get a Wideband O2 sensor and do your own logging or put the bike on a dyno with a wideband and 5 gas analyzer. With the OSB software or ECMSpy and Excel you can turn off thestock O2 and create your maps with the AFR you want and upload them to your bike. While OSB is easier it is also more expensive. ECMSpy is free but you have to use Excel to modify the maps which can be cumbersome. The most important thing to remember is that V-twins are unusual motors and you should tune each cylinder separately. This means welding a bung on the front pipe (pre 2010 models) so you can accurately tune it. A royal pain but it is the best way to tune each cylinder individually for maximum power. We all know the front cylinder runs cooler so its important to properly tune each cylinder with a wideband. Some will arbitrarily increase the front cylinder by a set amount but you are really shooting in the dark.
The best on the market is self-tuning. The idea behind self tuning is to place a wideband O2 sensor in the exhaust and have a controller that adjusts the maps. Where as before you had to drive around with a wideband, log the runs, then adjust the maps, repeat as needed till you dialed in to your AFR. Now you tell the controller what AFR you want and it tunes the maps for it. A great invention but of course costs more money then you doing the work itself. Look at Twin-tec for more information.
The last option is to find somebody who has tuned their maps and use there maps. While this will work, its not perfect. Every bike is different and every bike should be tuned individually. If I ever get motivated enough to buy a wideband and tune my bike properly I will be more then happy to share my maps. Just don’t hold your breath as I don’t plan on doing this for a while.
