Feature Request: Ford Injector Slope method

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seijirou
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Feature Request: Ford Injector Slope method

Post by seijirou »

Looking at injector dynamics explanation of the way Ford characterizes their injectors I this could be recreated in a small footprint for better low pulsewidth behavior.

http://injectordynamics.com/articles/fo ... erization/

The chart here can be pretty easily understood as the injectors behaving "larger" on the Low Slope up to the break point, and then "smaller" on the High Slope above the break point.
To represent this you would need.

Low Slope Injector Size
Break Point (ms)
High Slope (nominal) Injector Size

This data will come from Ford or Siemens Deka data sheet, like seen here: http://siemensdeka.com/specsheets/FI114992cs.jpg

Low Slope Injector Size is ALOSL * 3600, so for the above it's .028183lb/s * 3600 = 101.46lb/hr
High Slope Injector Size is AHISL * 3600, so for the above it's .020877 * 3600 = 75.15lb/hr
Break Point (ms) is FUEL_BKPT(lb) / (ALOSL / 1000), so for the above it's .00002421 / (.028183 / 1000) = .859ms

So for any nominal PW up to and including .859ms, re-calculate a new PW based on the Low Slope injector size. For any nominal PW greater than .859ms, continue.

This doesn't do anything about a PW that falls below the MinPW on the charts but it should expand appropriate behavior down to the MinPW instead of only down to the Break Point.
pete20r2
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Re: Feature Request: Ford Injector Slope method

Post by pete20r2 »

I'm also very interested in implementing this functionality. I'll give it ago myself over the next few weeks.
Any core developers able to give some pointers/guidance on the simplest implementation pathway?

I've had a look at the MS3 smallpw function to see if it's portable but it works on a table and is tied up in a larger fucntion.
Blown88GT
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Re: Feature Request: Ford Injector Slope method

Post by Blown88GT »

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seijirou
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Re: Feature Request: Ford Injector Slope method

Post by seijirou »

pete20r2 wrote:I'm also very interested in implementing this functionality. I'll give it ago myself over the next few weeks.
Any core developers able to give some pointers/guidance on the simplest implementation pathway?

I've had a look at the MS3 smallpw function to see if it's portable but it works on a table and is tied up in a larger fucntion.
Do update if you decide to give this a try. My approximation of this approach within the small pulsewidth implementation definitely suffers around the breakpoint since there's no way to do it without using 2 points to transition rather than a single breakpoint.
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