sct dataloging knock sensor

[esp3500]

I just raised the boost on my mustang and I want to datalog the knock sensors for detonation. which of the pids do I use from the list and what exactly am I looking for?

I have tried all the ones I see and none of them do anything.

 

[BruceH]

Are you using livelink to datalog?

 

[Swarzkopf]

I monitor SPK_ADD_KS. This displays the amount of timing added, or subtracted in the case of a knock event, by the PCM based on input from your knock sensors.

This PID will be effective IF your tuner left your knock sensors enabled. From what I understand, a lot of 3V tuners turn off the knock sensors. I have mine at factory sensitivity and actually made them more aggressive at removing timing vs stock.

While scanning for this value, a negative number indicates a knock event. A positive number indicates that the engine isn't close to knocking, and the knock sensors input is resulting in added timing as per the KS_SPARK_ADD tables in the PCM.

Alternatively, you can monitor the raw output of each knock sensor by scanning ks1_volts and ks2_volts. These will display the actual output of each knock sensor. My understanding is that the ~5000 range is where you normally need to start worrying, though please don't take that as gospel, it's my understanding. I will say that my 3V with a 3.33 pulley on a Novi 1200 often spikes 3000-3900 range right before shifting (6300 RPM), but hasn't even gotten past this.

Hope this helps...

 

[BruceH]

I keep it a little simpler. Using livelink I monitor spark source and spark. Spark source will tell you what is controlling spark.

 

[esp3500]

Thanks Guys.
That is perfect.
I should be ok becaues I am running a can tune
Thats set for 9.8 to 1 compression but when I forged the internals I went with 8.6 forged pistons like the roush 540r mustang has I figure the lower compression and the conservative tune Bama gave me I should be ok.

 

[Swarzkopf]

Bruce- I've never tried that route. What if multiple modifiers at are work at once? IE, your spark is being modified by both the IAT modifier table and the KS spark table at the same time- which shows in spark soure? Also, does it differentiate between spark added via the knock sensor and spark subtracted by it?

I also like the 'keep it simple' approach...I have had good luck monitoring SPK_ADD_KS as the primary livelink "gauge" while recording the KS volts for review when the pull is done. I always figured that if I see a negative value appear on SPK_ADD_KS while making a pull I can back out of it fast.

 

[Swarzkopf]

I should be ok becaues I am running a can tune

Just to be clear- you do mean the canned Paxton tune they ship with their kits? I'm pretty sure that it does leave the KS sensors intact. If it's from somewhere else, it may not have them active.

 

[BruceH]

Bruce- I've never tried that route. What if multiple modifiers at are work at once? IE, your spark is being modified by both the IAT modifier table and the KS spark table at the same time- which shows in spark soure? Also, does it differentiate between spark added via the knock sensor and spark subtracted by it?

I also like the 'keep it simple' approach...I have had good luck monitoring SPK_ADD_KS as the primary livelink "gauge" while recording the KS volts for review when the pull is done. I always figured that if I see a negative value appear on SPK_ADD_KS while making a pull I can back out of it fast.

Spark source 4 is pre-ignition. I also keep the knock sensors at stock levels and turned on. All of my adders are turned off.

I'm sure you know this but I'll repeat it anyway. Livelink has a help link. Click on help then source values. A nice popup will have all the codes. I always datalog spark source, torque source, and fuel source. This was suggested by someone smarter than myself and it's been a good suggestion.

 

[Swarzkopf]

Spark source 4 is pre-ignition. I also keep the knock sensors at stock levels and turned on. All of my adders are turned off.

Makes sense- this wouldn't work for my setup, as my IAT spark modifier table is pretty important in my file.

 

[BruceH]

Makes sense- this wouldn't work for my setup, as my IAT spark modifier table is pretty important in my file.

Mine is still set up to pull spark, just not add.

 

[GTGHOST]

i will have to check what mine is, i know with my tuning software (pro racer) i edit table values, its not just adding spark to the whole car, depends on load and RPM in a table. But i want to say in my data log i watch spark, RPM, and just assume load based of those values, with knock sensors on i can tell if its tickling them if it bumps it and backs off the stock 5 degree's it pulls (most tuners if they leave spark on i notice they edit the 5 degree pull to about 2 - 3 degree's)

 

[eighty6gt]

Does anyone know if the PID "SPARK ADDER KNK SENSOR ARRAY[0]" can have positive or negative values? I bet just positive values, and the value is degrees removed.