In a car, a performance tune (or chip) adjusts both the mixture and the timing advance. How about in a Harley? Fuel only or ignition timing too??? And is it the same for pre-07 injected engines with no oxygen sensor and post-07 engines with oxygen sensors???


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Depends on the tuner. Mine (ThunderMax) does both.

 

Yes.
Yes.
And yes.

 

Ed, what you'll find with Harleys that is different from cars is that with Harleys, there are a number of different ways to "tune" them. You have resistors that plug in between your O2 sensors and main harnes that will send a different voltage to the ECM to trick it into thinking the engine is running lean and thus richen mixture. You then have piggy back devices that also spoof the ECM into doing different things depending on the device. Some are "set" to a generic map and others you can tweak the settings. Last is probably what you're more use to in the car world where you can actually re-write the ECM tables and this last option has the most control over what you can change.

I have the last option in the form of the PowerVision and I know that lets you tweak almsot everything just like my PowerTuner did for my 99 Grand Prix. I believe some piggy back devices will let you do both fuel and timing as well.