Knock retard per cylinder - testing

Testing and development of Megasquirt 3

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jsmcortina
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Knock retard per cylinder - testing

Post by jsmcortina »

I've been working on my next TODO item - respond to knock per cylinder.

Would anyone like to test this out?

My test regime would be to put my car on stands and load the engine up with the footbrake to put it in the low RPM, high load areas of the table. Then use spark trim to artificially advance one cylinder and confirm that the knock control system pulls the timing back on that cylinder. There's a debug option to see retard per cylinder. You'd need to be watching that for all cylinders and the knock level per cylinder. (Don't break your engine!!!!)

This will only work on installs that can detect knock per cylinder. e.g. sequential installs using the internal knock module or MS3-Pro.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

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elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

James,

I'd be happy to give it a try!
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
jsmcortina
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Re: Knock retard per cylinder - testing

Post by jsmcortina »

elaw wrote:I'd be happy to give it a try!
Sent by email.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

Got it... thanks!

We've got both a major snowstorm and a major holiday coming up, so it's possible I won't get a chance to test until Friday or Saturday. But I'll do it as soon as I can and report back.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
tpsretard2
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Re: Knock retard per cylinder - testing

Post by tpsretard2 »

I am willing to test james.
jsmcortina
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Re: Knock retard per cylinder - testing

Post by jsmcortina »

tpsretard2 wrote:I am willing to test james.
Sent.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

I loaded up the firmware a couple of hours ago and have been fooling around with it... things seem good but I'm not sure how to tell if it's working?

I'm attaching an .msq and a zipped log. One note: I started the trip out with additional advance applied via the spark trim table only to cylinder #1. About halfway through, I made the same change to the #3 trim table.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
jsmcortina
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Re: Knock retard per cylinder - testing

Post by jsmcortina »

The log doesn't show any retard on cyl#3,4,5. I can't tell what's happening on cyl#1,2 because you are actually using the Sensor01, 02 inputs for something. That's where the retard per cylinder is stored when debug=on.

The knock volume for cyl#1 and cyl#3 doesn't stand out as being much different from the others.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
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elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

Okay, I may have to be a little more aggressive with the timing. It's been pretty cold out, and the timing was tuned when it was warm so there's probably quite a bit of headroom. And I think I can turn off the two generic sensors... they're not important.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

And... I think we have success! Although being able to log spark advance per cylinder would be nice to be really sure.

Since the number of allowed attachments is limited, I'll break this up into 3 posts.

First: the baseline. This .msq and log are from a run with normal timing settings - no knock was expected or seen.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

Next: this run is with the timing advanced considerably in the main table, and with advance added to #2 and #3 and taken away from #4 and #5 in order to increase knock tendency in cylinders #2 and #3. This is with per-cylinder knock retard *off*.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
elaw
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Re: Knock retard per cylinder - testing

Post by elaw »

And lastly, a run with per-cylinder knock retard on... all other settings remain the same. In both this and the last log, you can see #3 tends to knock more than the others, and in this log #3 is the one with the most knock retard applied.
Eric Law
1990 Audi 80 quattro with AAN turbo engine: happily running on MS3+MS3X
2012 Audi A4 quattro, desperately in need of tweaking

Be alert! America needs more lerts.
jsmcortina
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Re: Knock retard per cylinder - testing

Post by jsmcortina »

Yes, that looks to be working as it should.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
tpsretard2
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Re: Knock retard per cylinder - testing

Post by tpsretard2 »

have done a lot of testing the last few days.

I always had a cylinder that was louder than others, #4 i can easily get that one cylinder to retard and not the others.
I had to disable the Generic sensors, but other than that, i can not find any problems with the implimentation or how it is working.
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