OK thank you for a useful response.


Everyone else, why don't you just go back to sucking dicks.

 

FTFY. If you have noise problems through 4500-5500, the solution is frequency/RPM based filtration, not ignoring the damn sensor.

Call me when you grenade your motor after ignoring your knock sensor through the torque peak.

 

Agreed. This is why for example TI makes very nice DSP ICs for knock sensing that the OEMs use in their ECUs and tune for a specific engine.

 

I believe one of the planned features of the next full number release of the megasquirt 3 firmware is the ability to window and bandpass the knock input. I'm not sure what the plans are for sensitivity versus RPM curves, but the windowing and filtering alone should make a significant difference compared to a simple noise threshold.

 

I know on my evo8 and early evos the knock sensor was to sensitive. The tuner that tuned my car in some cases would change values to "de-sensitize" the knock sensor. Can that not be done in this case?

 

It is literally what they just talked about in the posts before yours

 

Eventually it won't matter as much as companies will develop spark plug associated pressure tranducers that will allow direct detection of the pressure spikes associated with knock not just the vibrations. I think NGK is working on this but I don't know what the time frame for commercial introduction is(edit they have a picture on their website that says in development). But for now filters and signal processing are all that is available.
If you are really worried about this buy a more sophisticated knock detection system like Phormula or Gizzmo Kmon or sometehing like that.

 

Knock sensing spark plugs? hot damn I haven't heard of that yet lol.

And sav you keep referring to the stock NB knock sensor as crap, what do you suggest is NOT crap for our cars and what are you using on your race car? IIRC you're using the same stock sensor that we are.

Do you know of anyone on here (or anyone with a turbo miata for that matter) using something like this?
I'm curious how it compares to the stocker.
Feedback from someone using them would be great.

 

I know someone (not at NGK) who is working on it. It is a completely different way of sensing knock; it is pretty cool. I am not sure how much I can repeat (proprietary) so I will keep my mouth shut on the details. But if you google it I'll bet something will turn up. AFAIK it is still developmental technology and is not mainstream yet.

 

I used some of the Phormula products when my car was tuned on the dyno, they do everything that they claim they do. Anytime they are mentioned on this forum, people run away because they aren't cheap or free.

 

Not quite mainstream. There are several companies like optrand and Kistler that make these kind of sensors mostly for engineers
http://www.optrand.com/products.htm
this is the NGK picture which indicates it is probably similar to the optrand products http://www.ngkntk.co.jp/english/prod...thers/gps.html

there is a company that I know of that has taken these sensors and made commercial packages for test bench(read professional dyno) or in car set ups
http://www.tfxengine.com/. This would be the ultimate knock detection setup

 

I did not mean the pressure sensors, though that works too. I meant something more like this (from Delphi):
http://delphi.com/manufacturers/auto...gnsys/ionized/
Ion Sense knock detection eliminates vibration-based knock sensors for lower system cost and improved knock sensitivity and detection. Knock detection is robust to valve train and other mechanical noises.

Looks like it is more mainstream than I thought.

 

Yeah I forget about that. Don't some Harley-davidson motorcycles use some form of that method?
Very cool in any case.

 

Saturn sensor with on-board frequency filtering (thanks J_Man for the setup info), connected to an AEM with RPM and timing window filtering.

For all the swooning done over MS3, I kind of assumed it had good knock control - really sad to hear they still haven't done it. The new AEM boxes combine the RPM filtering they had before with on-board user-adjustable frequency filtering. Super bitchin'.

 

The MS3 is still relatively new. They only released the 1.0 firmware on Jan 12 of this year.

Knock windowing (unsure on freq based filters) is due for 2.0 along with 4-cam VVT and who knows what else.

But you're right. As of this moment, it essentially has zero knock control beyond "some box says there is knock so I will do X".

 

my bad...

 

no worries. I'm kinda sad that the ms2 doesn't have windowed/filtered knock sensing.
that's so far the 1st thing since switching from the adaptronic that I don't like about it.

 

18psi sorry for grave digging but why did you decide to go from adaptronic to ms2?

 

is this natural knock sound something thats more common with the 99+ motors?
my 1.6 is smooth through out the whole power band.

 

couple reasons, many of which were addressed with teh adap 440.
fully pnp (didn't require a big *** adapter harness)
internal map sensor
easier to set up
better startup
better idle
overall much easier to work with and user friendly
tons and tons of info and writeups and faq's
MUCH more user support.
Travis was great and helped us a ton, but when there was something he didnt know, we were pretty much fucked. had to figure it out on our own.
few other reasons, all of which were minor, but all that **** added up and I got tired of it. decided to try the diypnp and LOVE it.
as far as I know yes. 99-00.