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Old 12-24-2009, 09:00 AM   #9 (permalink)
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How do you tune individual cylinders? How do you get your feedback for individual cylinders? I guess you do this on your del sol.

On TDI engines, each power stroke is sensed by the crank sensor and fuel trims for individual injectors are adjusted to compensate for variations between cylinders and injector bodies and make the engine run smoother.

On a gas engine with perfectly matched injectors and cylinders I can see how you could compute individual cylinders AF ratio from the power they generate given an equal quantity of fuel injected in each cylinder. But as soon as there are mechanical variations between cylinders, say uneven compression for example, or something that throws an injector's flow off, that all goes out the window.

I think it would be easiest for manufacturers to ensure their intake manifolds evenly distribute air between cylinders, or just go with an o2 sensor per cylinder.
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