trying to get a hold of the timing stuff. Im looking for some resolution of these 2 tables versus KR. From my understanding the computer interpolates between them. So if at WOT im showing 16*, ignoring for now all modifiers, and i get a 4 degree of KR, I know have 12 at WOT. I dont understand when the low octane table comes in. Does it step in after the max of 8 degrees is pulled? It also seems to me the computer is in between them all of the time, if you have FI high low octane talbe set up, should u just add timing based off of AFR or what, if wanting to add at WOT. Thanks for any links and or help.

 

 

The PCM will use the high octane table exclusively until KR is detected. It will interpolate between the two tables (high/low) based on the amount of KR it receives. The KR only directly pulls timing when the PCM detects knock through the sensors, it will reduce the timing and bring timing back using a decay rate which you can modify. When tuning for timing set the high and low octane tables the same until everything is happy, then pull 4 degrees or more out of the entire low octane table to leave the pcm with somewhere to go if you get a bad tank of gas and a lot of KR.

 

So KR is only from the knock sensors readings, so to speak. Once KR is cleared, or stepped out, were back to High octane. Ive been trying to tune a friends while mine is on jack stands and i get random spikes with big KR degrees, but i think its from misunderstanding more than anything.

 

The PCM uses the KNOCK Learn parameter to bias between High and Low table. Knock learn can be between 0 and 1. At 1 it uses High table exclusively and anything lower it will bias toward the low octane table. I don't know the math.

I have done hours of logging Knock Learn and its effects. Every instance of knock will lower the Knock learn value instantly. It takes miles and miles of driving with 0 knock before it will begin to increase the Knock learn value.

I keep the routine working as the truck is mostly a driver and it is a good safeguard against bad tanks of gas or whatever. Its also a good indication of how much knock is going on if you don't log every minute. Just connect and log Knock learn. If its a very low value chances are you are seeing a lot of knock while driving. If it's near 1 then you haven't been seeing a lot of KR. When I go to the track I will reload a tune which will reset the Knock learn factor to 1. The other fix for not having any timing pulled long term for knock is to copy high octane table to low octane table.

 

Adaptive Spark Scaler is the EFILive term for HPT's "Knock Learn Factor".

By modifying the Octane Scaler Threshold (B6223) above the knock retard limit, you can effectively disable the knock adaptability.