The new Ecuflash V 1.27 includes tunable parameters on the so called

"Knock Filters"

DO NOT touch those unless you have a specific reason to do so

The # 1 best thing about the oem tune is its bullet proof knock protection

Unless you can specifically identify some area that is mis adjusted due to exmaple a built bottom end and have a specific need to mess with these functions . . .

Don't

Danger

 

I second that.. These filters are set up to do an AMAZING job on the ECU, don't alter them unless you specifically understand what they impact, or are instructed to do so after talking to an experienced tuner.

 

I would say don't touch them unless you are an experienced tuner.

Knock Protections is priceless.

 

From looking at the table, I assume they map the 'acceptable' and expected noise level from the knock sensor. Is this correct?

d

 

Yep, its basically a threshold where below that point it ignores the noise.. The fact that there are several filters is what stumps me.. I think varying loads, and conditions, determine which knock filter is used, but I have no data on that yet, I'm not even 100% sure what the units in the table represent..

Worse comes to worse, you can ask the guy who's disecting the roms (Jason at Mynes Performance) but Ive been trying to help out so he can focus on finding us more goodies..

 

The only way I can figure a bad BOV causing eng damage is it sticking shut.

 

Does the knock sensor microphone output a 0-5V signal? Or does it actually report frequencies (Hz)?

Actually if the tables do represent frequencies (i.e. octaves), then the number of tables (12) almost makes sense, since they could represent the following octaves:

6.875 Hz
13.75 Hz
27.50 Hz
55.00 Hz
110.0 Hz
220.0 Hz
440.0 Hz
880.0 Hz
1760 Hz
3520 Hz
7040 Hz
14080 Hz

The attached PDF has some info on engine exhaust tones; e.g. which frequencies an engine generates as it is turning over.

l8r)

 

Anybody have the info on what units the knock sensor filter are in yet? Pls share.

 

Well I do know that the Knock Filters in the 03's are more sensitive. I changed over to an 05 Knock Filter Map and raise everything 2points and I show less knock. and Im still running 11.0 A/F. Also Trapped 2MPH with same tune, trap 4MPH with my leaning the A/F out to around 11.5-7.

 

The Evo uses a flat response knock sensor. The voltage is very low that it puts out. The knock sensors work on frequency. Every engine has its own frequency range so the sensor has to be made for a certain frequency range.

 

So the ECU responds to what kind of sensor output when a "knock" frequency is detected

 

fwiw
guessing from what I have seen on my hydra maps, the voltage is likely 0-5 volts, Where 1.x volt gets you some retard(?)

Cams and S&R install would have an effect on your knock detection too.

Headphones may be the best way through this maze.

It is very interesting that there are so many knock maps in the stock system. How could they be used? I wonder if they were developed for different mechanicals and were not discarded so they might be used in future motors with different profiles.

 

Ok the I misread the original question on the knock sensor. The knosk sensor does produce voltage when knock is present. The higher the knock the higher the voltage. I know this because I checked it with a volt meter.

I use the PLX Devices R-500 which you tap into your stock knock sensor and can use headphones. I also bought another knock sensor and added it on the head where people mount the sensor for Knock Link and I log that voltage.

 

I think each map represents a different frequency range.. Within each map's range, probably represents an intensity value that has to be exceeded in order to create a valid "Knock Count"

You put the maps together and it creates a signature for different loads and RPM's.. I think the signature of frequencies is what determines what is knock..

I'm extrapolating this information logically, since its not really documented ANYWHERE, but it makes sense since a clunk could be the same intensity and volume as a knock, but its signature (combination of frequencies) would be different..

The easy way to test this theory is to build a 4d map (what someone would use for a spectrum) and compare two otherwise identical ECU's, the Standard Evo map, and the same P0300 fix map.. since the mitsubishi tech bulletin acknowledges that its probably driveline noise being transmitted to the crank... In comparing the two, you should see the low RPM low load, and cruise RPM low to medium load areas have different values between the two. (FWIW I haven't looked closely at this yet because I have not experienced any P0300 codes that couldn't be attributed to either my ECU+ or changes I had made to the car)

 

I just wanted to bring this back to life to see if there is any interest. Some also has mentioned to me that iron blocks are more "noisy"... any truth to this?