miatauser884

iTrader: (11)

Give me a picture with your cursor of the region the knock is occurring.

Reverant

iTrader: (10)

I need to find that datalog again first. I have like 100 datalogs for the new version of the Enhanced MS2.

miatauser884

iTrader: (11)

Ok, I know I am asking for a lot, but...........Y8s, Reverent,

Would you two mind posting a bunch of knock scenario datalogs? I'm going to post what I see when I get home. I'm having a tough time deciding what is knock, and what is just noise.

y8s

iTrader: (8)

These are both lean tip in knock.



You can see in this one that the noise bled over into the next cylinder (or it also knocked maybe)



I would say you shouldn't rely purely on level. You have to use a sort of "know it when you see it" evaluation.

Of course if you HEAR the knock (like my lean tip in knock) then you know. I could hear it.

miatauser884

iTrader: (11)

Did you guys take logs with the knock retard turned off, then slowly dial back timing until spikes disappeared? I'm surprised by the amount of timing I am pulling, but it does seem to make a difference

Reverant

iTrader: (10)

y8s, you have too much timing for that particular rpm/load cell.

y8s

iTrader: (8)

That's an old log but I think it is off.

is that to say I'm probably past MBT and/or slowing down my spool?

what does your midrange timing look like?

Reverant

iTrader: (10)

25-27. I was knocking around 29-30.

miatauser884

iTrader: (11)

I looked a t a log this morning, and the timing I have pulled is making an impact. I'm surprised by the number of knock events I was seeing below 100kpa. I was also seeing some when transitioning from higher kpa to lower kpa. I don't think the timing change was fast enough to avoid a knock spike.

The next question is.....Does one lone knock spike matter all that much when it happens over a fraction of a second.

y8's I'm noticing at high rpm and high boost that my knock signal is approaching what appears to be the max level 102.1% It doesn't look like knock, just an increase in signal strength. If I lower the gain in my settings, will it keep it from maxing out?

Oh, and I have turned off the knock retard so i can log the knock and try to tune it out.

Reverant

iTrader: (10)

Yes, decreasing the gain will allow you to not max out just by noise alone.

miatauser884

iTrader: (11)

I am seeing this as well. I 2200rpm to 3100rpm at 68-80 kpa I'm down to 25 to 27. I was over 30. 42-50 kpa I'm right at 30 degrees

This seemed to be a big area where I ws getting knock, but I'm slowly tuning it out. I have a feeling I will end up lower than it currently is. Once I feel like I've tuned out the knock I will post a before and after of my ignition table.

y8s

iTrader: (8)

I was knocking originally but after correcting the leanness it went away.

miatauser884

iTrader: (11)

Is there a way to estimate mbt. My original tune didnt have audible knock. I checked the pistons when i pulled the head, and i had no signs of det. Yet the knock sensor is definitely detecting something. If u back off the timing until the sensor stops detecting knock. Wheredoes this put you with respect to mbt? It appears to be an uber safe tune that you can flog without fear of blowing up. It probably also builds in a margin of safety if you go a little lean

Reverant

iTrader: (10)

You should be able to run ~14.7 at 70-80kPa at < 3000rpm without knocking at all. The fact that you were knocking at that load with a 13.2 AFR says a lot.

y8s

iTrader: (8)

does this give you warm fuzzies?

the map you don't like:




one you might like more:



Honestly I haven't messed with my spark map much in the last... 5 years. The original map I had was from FM for the hydra and was ridiculous.

miatauser884

iTrader: (11)

The area u changed is the same place im finding that i have to pull some timing.

y8s

iTrader: (8)

Here is running the second map. It's interesting to note that the noise level does not increase with RPM while I'm in boost

This is about 3700 to 5600 rpm. So a little higher RPM starting point, but the initial knock noise is much lower.

I take a lot of datalogs.

Faeflora

iTrader: (2)

You may take a lot of datalogs but you must not look at them. If you did, you would see that noise does indeed increase with both load and RPM.

Stop datalogging on arlington blvd or whatever that road is that has 25mph speed limit.

3rdCarMX5

iTrader: (1)

I have my sensor installed and have been logging. I'm at work so I can't attach anything. I had a pretty nasty lean tip in knock, that went away- but I find that I am having to go very rich with the resolution I have in my AE chart. I will have to look at what others have.

I also notice a noise spike when I let off the gas and AE enters into the negative TPSdot. Anyone else see this? It will go from 20 to 40 when I let off the gas and then settle back down to 20, but not if I pulse the throttle.

cyotani

iTrader: (8)

I'm working on setting up my knock setting on an NB running and MS3X (stock knock sensor)
This is on a mostly stock naturally aspirated engine.

I tried to systematically set up knock. I set the bandpass to the theoretical frequency of the miata bore size.
Then did two WOT sweeps at -5 and -7 degrees timing pulled from the stock MSPNPpro base map.



I assumed that these two pulls were very safe in timing and detestation free so I set my knock threshold slightly above the knock signal of those lines.

I then ran a pull with 8 degrees added at 3000 rpm to try and induce knock. The knock input was slightly over the first two pulls but not the magnitude I had hoped (no audible knock was detected).



I then tried 10 and 20 degrees added at 4000 rpm. Here, you can see a pretty sizable change in the knock signal but still not the magnitude that I had hoped to see.




After, I ran more pulls at of the basemap spark. These pulls seemed to be knock free, however, some points lie slightly above the knock threshold I set from the -5deg and -7 deg pulls...





I'm not sure If I should accept these as tiny knock events or if I should increase the threshold slightly that the baseline knock lines are below the KNK threshold?


Here is my current settings: