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      02-09-2013, 02:13 PM   #55
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Originally Posted by Mangler View Post
So with this theory the cylinder bank individual runner lengths would have to be in the algorithm for that cylinder. If any aftermarket change in runner length for that cylinder would throw off the timing of the pulse capture. Sounds legit.

Yeah it'd really be just an advanced method of fuel trimming each cylinder mainly for emissions purposes but the usefulness for performance is obvious. The point is, and you bring up runner length, there's a load of assumptions in here that one would be wise to understand before breaking out the welder.

I do not know for a fact what they are doing, the papers and patents I was looking at were older. But they seemed to imply impending CARB/EPA rules for individual cylinder emissions monitoring capability. Wideband sensor + DI and some signal processing makes that possible.

Obviously another part of the whole algorithm is individual injector modelling. I mean I read about this and said since when? But you have to ID injectors now and hand off that model to the ECU or it won't run right.

In control theory terms there's something called system identification, or system ID. Basically modeling the dynamics of part of the system being controlled so you can anticipate responses better. This can be done on line (like with coded pulses), off line and then inserted into the algorithm (like with injector ID'ing), or just part of the hard coded algorithm and not explicitly called out (like maybe runner length). It is good to know which one of these cases something you are messing with is and how it is reflected in the architecture.