ITT we discuss knock windowing - Miata Turbo Forum - Boost cars, acquire cats.

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Old 03-04-2013, 09:08 AM   #1
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Default ITT we discuss knock windowing

And when I say 'we' I mean other people much smarter than me.

Seriously though, has anyone figured out MS3's knock windowing and got good settings that work well?

Failing that can someone explain how I would go about tuning it, as I haven't the first clue where to start.
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Old 03-04-2013, 12:37 PM   #2
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Google source information A suggests peak cylinder pressures are somewhere between 20 BTDC and 60 ATDC (fig 1) depending on spark advance. The anecdotal google sourced reference (fig 2) below suggests that knock occurs in the latter 2/3 of that. It was a VEMS isntallation page I think.

they used 12-60 ATDC.


FIGURE 1



FIGURE 2
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ITT we discuss knock windowing-pressure4.jpg   ITT we discuss knock windowing-cylinderpressurecurve.png  
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Old 03-06-2013, 05:19 AM   #3
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Thanks Y8s.

This is what my knock output looks like with the settings from a non tuned basemap:


Yesterday I created this based on Reverants guidelines, (take the timing at 75kpa as the knock window start)


Which resulted in this rather surprising result..... I was hoping for less on the graph, but literally nothing is very surprising, surely there must be some noise during these windows?
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ITT we discuss knock windowing-knock.png   ITT we discuss knock windowing-knock%2520window%2520settings.png   ITT we discuss knock windowing-knock2.png  
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Old 03-06-2013, 10:08 AM   #4
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Old 02-26-2015, 09:58 PM   #5
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Bump.

What is everyone using now? I just started up my engine on Rev's BASIC MS3 base map today. I noticed the Knock window start's later (further after TDC) as RPM increases. I guess that makes sense because max cylinder pressure shifts the same way as you retard timing towards TDC. It just seem's to be a fairly large change. At redline the window doesn't start till 30* AFTER TDC.

So now that a lot of you are playing with knock windowing, what are your results?
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