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Old 09-06-2011, 01:16 AM   #1
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Default Knock-window...it is time

Will this ever happen?
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Old 09-06-2011, 07:52 AM   #2
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In MSIII yes 100% definitely, I think it's scheduled for the code 2.xx release on MSIII. The coders are writing a new clock angle algorithm thingy (way over my head) which will allow this to happen.

in MS1/2 no never ever ever.
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Old 09-06-2011, 08:00 AM   #3
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I believe it has something to do with your sig quote.
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Old 09-06-2011, 09:25 AM   #4
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MS3 alpha code has some awesome knock stuff going on. When Ken gets his angle clock code done, it should get even better.
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Old 09-06-2011, 11:49 AM   #5
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How about 2D rpm filtering and user-adjustable frequency filtering?
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Old 09-06-2011, 12:10 PM   #6
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What is knock window?
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Old 09-06-2011, 12:17 PM   #7
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Quote:
Originally Posted by Savington View Post

How about 2D rpm filtering
There is already a sensitivity vs RPM function.

Quote:
and user-adjustable frequency filtering?
That would be a hardware function of the knock conditioner. Keep in mind current MegaSquirt hardware does not include an onboard conditioner--You have to use an external box such as KnockSenseMS or a GM ESC module.

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What is knock window?
Looking for knock only at specific crank angles when it can occur. It helps to eliminate false knock signals. It can also be used to determine exactly which cylinder is knocking.
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Old 09-06-2011, 04:03 PM   #8
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Quote:
Originally Posted by hustler View Post
Will this ever happen?
I plan to offer this on my next generation of Megasquirt II ECUs.

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Originally Posted by richyvrlimited View Post
in MS1/2 no never ever ever.
Unless of course, I have say in this.

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Originally Posted by Savington View Post
How about 2D rpm filtering and user-adjustable frequency filtering?
Most definitely. The frequency will be fixed based on whether this is a 1.6 or a 1.8, and there weill user-adjustable RPM filtering.
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Old 09-06-2011, 06:06 PM   #9
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Quote:
Originally Posted by Reverant View Post
I plan to offer this on my next generation of Megasquirt II ECUs.



Unless of course, I have say in this.



Most definitely. The frequency will be fixed based on whether this is a 1.6 or a 1.8, and there weill user-adjustable RPM filtering.
Just



Quote:
That would be a hardware function of the knock conditioner. Keep in mind current MegaSquirt hardware does not include an onboard conditioner--You have to use an external box such as KnockSenseMS or a GM ESC module.
Now that's disappointing. I was under the assumption one of the spare analogue MS3X inputs would be able to be used to analyse the knock signal.

Relying on a KnockSenseMS is pointless, it doesn't rpm filter so you just get noise induced knock BTDT. No amount of MS trickery will stop a poor input signal.

Shame.
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Old 09-06-2011, 07:31 PM   #10
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Quote:
Originally Posted by Ben View Post
Looking for knock only at specific crank angles when it can occur. It helps to eliminate false knock signals. It can also be used to determine exactly which cylinder is knocking.
That's pretty darn cool. Does this exist in any EMS's out there, factory or aftermarket?
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Old 09-06-2011, 08:48 PM   #11
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6.5 kHz bandpass filter is appropriate for the miata. And then said knock window.

I have a schematic for a simple bandpass filter somewhere. One could maybe add it on board a MS.
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Old 09-06-2011, 09:02 PM   #12
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EDIT: Realized this is for MS

ProEFI has this...
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Old 09-06-2011, 11:21 PM   #13
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Quote:
Originally Posted by Faeflora View Post
That's pretty darn cool. Does this exist in any EMS's out there, factory or aftermarket?
yeah a good amount of the more expensive EMS solutions have support for knock windowing.
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Old 09-07-2011, 12:26 AM   #14
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AEM has it and AEM is fairly inexpensive.
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Old 09-07-2011, 12:31 AM   #15
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Quote:
Originally Posted by hustler View Post
AEM has it and AEM is fairly inexpensive.
I meant more than megasquirt costs, which I paid about 300 after I did mine up

I use a J&S safeguard on my miata for knock detection and retarding per cylinder
Got it for a good price so I jumped on it.
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Old 09-07-2011, 12:50 AM   #16
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This thread has made my upgrade to MS3 worth it. Thank You!
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Old 09-07-2011, 01:05 AM   #17
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For people who don't know how knock-window works:
Attached Thumbnails
Knock-window...it is time-knockwindow.jpg  
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Old 09-07-2011, 12:08 PM   #18
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Quote:
Originally Posted by richyvrlimited View Post
Now that's disappointing. I was under the assumption one of the spare analogue MS3X inputs would be able to be used to analyse the knock signal.

Relying on a KnockSenseMS is pointless, it doesn't rpm filter so you just get noise induced knock BTDT. No amount of MS trickery will stop a poor input signal.

Shame.
An analog input reading the knock signal won't work. It doesn't have enough sampling speed to use an analog input for knock processing.

The knock sensing will use some more sophisticated hardware - I wouldn't count out user specified frequency ranges or other features.
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Old 09-07-2011, 01:33 PM   #19
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The windowing not only ID's which cylinder is knocking, it filters out noise that occurs outside said window.
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Old 09-07-2011, 03:30 PM   #20
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Quote:
Originally Posted by Matt Cramer View Post
An analog input reading the knock signal won't work. It doesn't have enough sampling speed to use an analog input for knock processing.

The knock sensing will use some more sophisticated hardware - I wouldn't count out user specified frequency ranges or other features.

? So how do other EMS's analyze the signal? Does the analog voltage signal go through an A/D converter and then through a DSP chip before feeding into a closed loop "burned in" timing trim?

I'm not trying to derail the discussion from MS; I'm just curious about how this stuff works.
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