XB BAROMETRIC SENSOR
What is a Baro Sensor and why would I want one on my Buell XB motorcycle?
The EFI systems on Buell XB motorcycles rely on a narrow band O2 sensor signal to maintain a specific measured air fuel ratio (AFR) during cruise riding. This is necessary to meet emissions standards and provide optimum efficiency. In the cruise speed range of about 40 - 70 MPH the ECM will make adjustments based on Exhaust Gas Oxygen (EGO) data provide by the O2 sensor to maintain the optimum AFR of 14.7. This is also known as Lambda 1.0, Stoichiometric, or Stoich. If a certain number of repetitive EGO adjustments are made the ECM will make a change to the Adaptive Fuel Value (AFV) setting. The AFV setting is a global change to the ENTIRE fuel map. Therefore, if the ECM senses that the engine is running rich while cruising at 50 MPH and lowers the AFV 10% from 100 to 90 the fuel delivery at wide open throttle (WOT) will also be reduced by 10%. As these bikes age and get modified, the data provided by the O2 sensor may becomes less accurate and/or usable. The sensors get dirty, rings and seals wear allowing some oil to be burned, performance mods are made, etc, etc. Fuel calibrations, or "tunes" made for a brand new bike running on a dyno don't necessary work perfectly on a 15 year old motorcycle being driven down the highway. Additionally, a narrow band O2 sensor isn't actually measuring the AFR like a wideband sensor can. Instead, it can only tell the ECM that the gases are either richer or leaner than 14.7 AFR. Very often, the ECM begins to sense a RICH condition and reacts by LEANING out (decreasing) the fuel delivery unnecessarily. This gradual process will often go unnoticed until the bike starts to run very poorly, overheats, or when you connect and view certain settings using Ecmdroid or tuning software. If it's not resolved it can lead to serious engine damage.
Where do I get the modified EEPROM file?
It is included with the kit. Simply save your original file as explained here and email it to info@buelltooth.com. It will be returned with the necessary changes.
I have an aftermarket exhaust and K&N filter installed but I haven't had the bike tuned. Will this make it run correctly?
No. This is not a replacement for proper tuning. You must have the bike tuned or have a matched calibration installed on your ECM to benefit from this kit. You can request a matched tune here.
I still have the stock exhaust system on my bike and the muffler valve is still active. Can I still install this?
- On 2008+ models you can. Be sure to order the kit that matches your configuration.
- On 2004 - 2007 models you cannot have Active Muffler Control (AMC) and Baro sensing at the same time. You would need to have an aftermarket exhaust system without AMC installed in order to activate baro sensing.
I live in an area that is relatively flat. Will this feature help me?
Only when you travel to areas with significant elevation changes. Once your bike is tuned for your location you can safely run open loop or set a minimum AFV to prevent the ECM from leaning out the fuel delivery. Therefore, baro sensing would be good for those occasional long rides or if you do track days/racing in various locations.
The negative side effect of preventing the ECM from adjusting the AFV on an XB is noticed when the bike is ridden in areas of significantly different altitude then what the bike was tuned at. In stock form, the only way the ECM can compensate for altitude is based on data from the O2 sensor. As altitude increases, the AFV decreases and vice-versa. This is not the optimum method, but it's the way these bikes came from the factory. These changes to the AFV are not constant or necessarily accurate.