I am tuning my 2007 Kraftwerks supercharged S using KTuner. My ECU pulls about 0.5-1 degree of timing from what is specified in the corresponding High Cam Ignition Table cell above 1750 mBar. On a WOT pull, the timing matches my table EXACTLY through 1750, but is a little short at 1875 and 2000 mBar.

The motor is not knocking, my Knock Retard table is completely zeroed out, so KR should not be the cause. My IAT is about 86 degrees, well below the threshold at which the IAT compensation table should be pulling spark. Same thing with ECT compensation. Anyone have a clue why it could be pulling timing?

 

I found that my Knock Limit tables were not set properly. This could be the cause, I will test it tomorrow morning and report back.

 

Setting the Knock Limit table high seemed to help in the 1875mBar range, but it still drops a degree around 1900 mBar and up. I tried everything; KL tables set high with KR set low, both set high, I removed my IAT compensation (even though temps were too low to trigger it), and in every datalog it drops 1 degree from commanded at 1900. KTuner does not export Knock Retard, but watching it in the log in KTuner, the value remains 0 through all of the runs. I can always just add a degree at 2000 mBar, but I don't want whatever is causing that degree to be AWOL to resolve in some situation and then I have a more aggressive tune than I desire without knowing it.

 

So, to summarize, I have any high-temp ECT compensation set to 0, IAT compensation set to 0, Knock Retard tables at 0, Knock Limit tables set to 60, Knock Sensitivity unchanged from the Base tune, 0 observed knock retard, and I have exactly the timing commanded in my Ignition tables from idle to 1900, then it drops ~1 degree to redline.

 

Here is a screenshot showing the discontinuity. It is right at 1925 mBar, it drops 1 degree from commanded and never gets it back.