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-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   Knock-window...it is time (https://www.miataturbo.net/megasquirt-18/knock-window-time-60243/)

hustler 09-06-2011 12:16 AM

Knock-window...it is time
 
Will this ever happen?

richyvrlimited 09-06-2011 06:52 AM

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.

curly 09-06-2011 07:00 AM

I believe it has something to do with your sig quote.

Ben 09-06-2011 08:25 AM

MS3 alpha code has some awesome knock stuff going on. When Ken gets his angle clock code done, it should get even better.

Savington 09-06-2011 10:49 AM



How about 2D rpm filtering and user-adjustable frequency filtering?

Faeflora 09-06-2011 11:10 AM

What is knock window?

Ben 09-06-2011 11:17 AM


Originally Posted by Savington (Post 768079)

How about 2D rpm filtering

There is already a sensitivity vs RPM function.


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.


Originally Posted by Faeflora (Post 768088)
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.

Reverant 09-06-2011 03:03 PM


Originally Posted by hustler (Post 767986)
Will this ever happen?

I plan to offer this on my next generation of Megasquirt II ECUs.


Originally Posted by richyvrlimited (Post 768041)
in MS1/2 no never ever ever.

Unless of course, I have say in this. ;)


Originally Posted by Savington (Post 768079)
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.

richyvrlimited 09-06-2011 05:06 PM


Originally Posted by Reverant (Post 768188)
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

:bowdown: :bowdown:


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.

Faeflora 09-06-2011 06:31 PM


Originally Posted by Ben (Post 768092)
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?

JasonC SBB 09-06-2011 07:48 PM

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.

jtothawhat 09-06-2011 08:02 PM

EDIT: Realized this is for MS

ProEFI has this...

Techsalvager 09-06-2011 10:21 PM


Originally Posted by Faeflora (Post 768273)
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.

hustler 09-06-2011 11:26 PM

AEM has it and AEM is fairly inexpensive.

Techsalvager 09-06-2011 11:31 PM


Originally Posted by hustler (Post 768374)
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.

miatauser884 09-06-2011 11:50 PM

This thread has made my upgrade to MS3 worth it. Thank You!

hustler 09-07-2011 12:05 AM

1 Attachment(s)
For people who don't know how knock-window works:
https://www.miataturbo.net/attachmen...ine=1315368354

Matt Cramer 09-07-2011 11:08 AM


Originally Posted by richyvrlimited (Post 768240)
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.

JasonC SBB 09-07-2011 12:33 PM

The windowing not only ID's which cylinder is knocking, it filters out noise that occurs outside said window.

Faeflora 09-07-2011 02:30 PM


Originally Posted by Matt Cramer (Post 768514)
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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