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Old 01-31-2012, 09:21 PM   #45
Gnarly Adventurer
Joined: Oct 2010
Location: Bay Area, CA USA
Oddometer: 207
I'm new to this, so forgive my naive questions. As far as I can tell, the O2 sensor returns a voltage-coded signal that indicates the oxygen level in the exhaust and the ECU then uses this return voltage among other parameters to determine fuel injection timing and duration? With your programmable sensor, you are changing the transfer function between O2 and voltage such that the ECU is effectively fooled into thinking there is less/more (I'm not sure which) oxygen in the exhaust and adding more fuel than before?

If you were to take the O2 vs voltage plot of the old and new oxygen sensors and plotted them, would the shape of the lines be the same with a constant offset across the O2 range? (i.e. have you, e.g., lowered the voltage by .1 or whatever V for every O2 level?) Or is it more complicated than that?

If it's just a simple voltage change, it should be really really easy to splice a simple circuit between the O2 sensor and ECU that modifies the output of the stock sensor to match what you've programmed. Obviously, your setup allows a lot more tunability, but for those that want those benefits of a smoother bike yet need something simple, a little plugin circuit might do.

Many bikes have multi-map ECUs these days, especially sport bikes. Rather than have race/street/rain settings that aren't really that useful, I'm surprised they haven't set them up to be low octane/high octane/gas with ethanol in it maps instead. If everything is expecting 100% gasoline and you feed it 90% gasoline/10% ethanol, of course the fueling is going to go wonky.
rritterson is offline   Reply With Quote