If you are referring to the XIED's, they are not a tuner, they are a fuel enrichment device. Google XIED and got to nightrider web site for a complete explanation, Cost about $100 and you can install them yourself

 

Did pipes and air cleaner on mine and added vance and Hines fuelpak bike runs great very simple to do

 

You say changing the intake air flow has no affect? And you say intake air flow is controlled by the exhaust pipes? I don't think that's correct.

 

Total flow is controlled by the intake thru to the exhaust. If the exhaust system restricts flow you can let all the air in you want with little effect. Open both ends and now you have a pump with more flow capability. Put your hand over your mouth and blow. Now open your fingers a little, then a lot. Flow changed because you put less restriction on the output.

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Thanks. I think I'll stick to the established formulas I've been using for air flow calculations instead.They work pretty good for naturally aspirated IC engines.

 

A very good, common sense example. (that many will ignore in exchange for what they already think they know.)

 

I can see you are already way above the simple explanations. Good for you. Not everyone is.

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Closed loop fuel injection is capable of making real time adjustments based on exhaust gas composition sensed by the O2 sensors. Standard carburetors (not electrically adjusted) cannot adjust for altitude, temperature, humidity which all effect air density/mixture. It is my THEORY that the ECM can adjust fuel flow to adapt to changes in total flow up to the per-programmed adjustment limit. When that limit is exceeded it trips the engine light, most likely in this case with a "too lean" code. The ECM will increase injector dwell to maintain the factory air fuel ratio until the "that's not right" limit is reached. IF the factory tune is OK for a particular owner, why can't the air cleaner and mufflers be changed without a re-tune UNTIL the check engine light comes on. Now it really is too lean, but until that happens, the factory A/F ratio can be maintained.

 

I'm not above simple explanations. I'm above giving them out on topics I know nothing about. Not everyone feels the same. There are posts in this thread that demonstrate that very well.

 

Again you've proved my point. This is not the "internal combustion engine air pump theory" forum. Its about providing help to folks. If an explanation is too simple for the situation, in your opinion, please feel free to enhance or clarify. If you feel you are above that, or we are beneath you, then its best to not just throw jabs out there.

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