Boog

At WOT the logs show some massively negative numbers in the 'knock strength', sometimes down to -1500. I'm not sure exactly what units this represents, but the only thing close that I can find while searching for negative numbers is knock correction for retarding timing. I thought it might just be a negative scale, but I occasionally get a +13 on the logged channel, and it says it's not switching to the high det map when it goes negative.

Thoughts?
-Boog

djamps

iTrader: (1)

Since when does cipher log knock??

If it does now, you can assume safely it's another undocumented 'feature'.

Boog

Cipher doesn't, but I found 'knock strength' and 'HI DET' in the ROM editor logging options.

I did notice that every time knock strength becomes sharply more negative, I lose a couple of degrees of timing.

PunKidd

We are working on adding the knock parameters to the ROM editor. We have only added them for the a SMALL handfull of ROMs at this point, which is why it's not a released thing.
You just got lucky that your car was one of the ROMs we've done.

The "knock strength" is the knock counter. It jumps more negative every time the ECU detects a knock event and then it degrades over time. If there are too many events, the ECU will set the "high det" flag, and the ECU will switch to "weak sauce" mode where the ECU runs off of the high detonation timing map. The ECU is PROBABLY also reducing ignition advance when the counter goes negative, but we have not done much testing with it yet.

We're still playing with these and looking for some adjustable parameters in the algorithm, so expect to see more this summer.

Jared@UpRev.com

XChacalX

iTrader: (7)

I wish it was done on my ROM !!!! 1EA4A
since I'm still working on the MAF Table/AFR/Timing with the whole custom intake system and exhaust!
having knock sensor reading would be a nice tool to have !

I'm still waiting on the Knock listen device parts by the mail.

Boog

Thanks for taking the time to explain. Your efforts are much appreciated.
-Boog

PunKidd

I recall responding to someone in the last few days about getting the parts for the knock amp from Digikey or Mouser. I'm behind (as always) on emails at the moment, so if you were waiting for another response, sorry, not until tomorrow at the earliest.

XChacalX

iTrader: (7)

yeah that was probably me !
but no I didn't send another email

djamps

iTrader: (1)

I built the knock amps thing and use some bose noise canceler phones...very affective. I trust it 100x more than the knock reading for tuning purposes, but it would be REALLY nice to know what the ECU is doing...

Boog

What makes you not want to rely on the ECU's knock count? Does it not pick up all knock events?

PunKidd

I've personally never trusted factory knock counters 100%. I've always used headphones for big power cars at least. Human ears are just better at picking things up before the ECU.
This may not be the case on the newer VVEL vehicles like the 370Z/G37 which seem to have VERY advanced closed loop ignition control. I'm very interested to dig into it on these cars myself.

Jared@UpRev.com

Vince@R/TTuning

iTrader: (7)

When ya get this Knock sensor all figured out it will be nice if we can log, knock count, knock voltage, as well as adjust knock threshold per RPM that way we can lower the threshold, and pull timing with less knock noise when needed....

djamps

iTrader: (1)

For starters, I have no way of even knowing if it works (no logging, indicators, ect). I also have a feeling it's pretty lenient... I loaded a bad timing map once and it was knocking like crazy but the ECU never went to the hi-det map and I didn't see any obvious pull in timing in the logs.

Second, according to uprev there is no knock detection above 5krpm, so the headphones are critical to make sure nothing funny is happening up top when tuning.

Boog

For what its worth, I can confirm that at ~5200 RPM the knock count appears to reset (not to 0, but around 50% of what it was at 5100) and timing is no longer pulled.

Any idea how bad it would need to be before it kicks over to the high det map?

rcdash

iTrader: (18)

UPRev, thanks for publishing the DIY to hook up knock headphones. I implemented a while ago and I can hear a gentle buzzing at a frequency related to rpm, but no knock yet (only tried with dyno once and didn't push it). It is very nice to be able to listen in and ensure no pinging going on...

PunKidd

The knock window does stop between 5000 and 5800 depending on the ROM. Expect to see a new knock window adjustment in the ROM editor very soon. Probably within a couple of weeks. I'm surprised the counter doesn't actually drop to 0, but like I said before, we haven't been able to make time to do the needed testing on these yet.

djamps

iTrader: (1)

So is this official now for all roms? I heard uprev tuners were notified of the new knock setting and logging abilities.

PunKidd

The knock window is our there for all ROMs. Parameters still yet to come.

djamps

iTrader: (1)

Quick question -- is the knock logging only available in Rom Editor? And is there a way to log to CSV in rom editor?

PunKidd

Yes, the knock parameters are only available in the ROM editor. They are not Nissan standard parameters so we have to find them for every ROM we support and add them to the ECU definitions so the ROM editor knows where to log them from.
I JUST found out that you can only log with the ROM editor if you have an Osiris Tuner or Pro cable. The developers are working on fixing is so anyone with a Cipher cable can log from the ROM editor. We still only have the knock parameters in there for ROMs that share code with CF41A and CD003, but we'll work on getting the other ECUs added ASAP. Right now there are 3 cars here that our developers need to do testing on before they leave, so they can't work on this stuff at the moment.

You can already save the ROM editor logs to CSV. Just stop logging and click File >> Save in the upper left corner of the logging window.

-Jared@UpRev.com