Trying to get rid of last of knock, making it worse!

[weith1111]

So the tuning is going smooth, picking up around 5-8 counts of knock from 4500rpm to redline.
So I bump the AFC from -12 on 4k-7k to:
-8 for 5k
-7 for 6k
-6 for 7k

Log again and now I'm getting around the same knock for 5k, but around 20 counts for 6k and even more for 7k. What's going on? I'm getting RICH knock? Should I have picked up o2 on these logs to see if it's super rich (I keep hearing you can't trust the o2)?

log1
rpm knock timing airflow
3063 0 29 510
3125 0 28 555
3344 0 27 599
3375 0 26 668
3438 0 25 756
3594 0 23 876
3750 0 20 1021
3875 0 17 1235
4031 0 17 1500
4250 0 17 1594
4469 4 15 1601
4688 4 16 1607
4906 4 16 1607
5094 4 17 1607
5250 4 19 1607
5406 3 20 1607
5563 3 21 1607
5688 3 21 1607
5875 7 22 1607
6031 20 15 1607
6219 19 18 1607
6313 19 15 1607
6469 19 19 1607
6594 19 17 1607
6688 19 15 1607
6844 18 15 1607
6938 18 15 1544
6938 18 30 359
6500 9 43 239
6094 0 45 227

log 2
4656 0 25 1052
4750 0 20 1361
4781 0 18 1607
4813 0 15 1607
4906 13 13 1607
5000 13 13 1607
5063 13 13 1607
5125 13 14 1607
5188 12 15 1607
5219 12 16 1607
5250 12 16 1607
5313 12 16 1607
5438 14 15 1607
5500 13 15 1607
5563 13 15 1607
5594 13 16 1607
5656 13 16 1607
5719 13 16 1607
5844 12 17 1607
5781 12 17 1607
5969 12 17 1607
5938 12 18 1607
5969 19 15 1607
6094 18 16 1607
6156 18 15 1607
6188 18 15 1607
6250 18 15 1607
6250 18 15 1607
6344 18 15 1607
6281 24 12 1607
6438 24 15 1607
6438 31 12 1607
6500 31 12 1607
6531 31 14 1607
6563 31 10 1607
6656 30 10 1588
6625 35 9 1607
6719 35 11 1607
6781 35 9 1601
6781 35 9 1607
6906 35 8 1607
6875 35 8 1538
6969 35 8 1607
7000 35 8 1569
7000 34 22 498
6625 27 37 233

[spyderturbo007]

The only thing the O2 is good for is a rough estimate as to where your AFR is at. With 550cc injectors you settings of -6 to -8 are way too rich. You should be somewhere around -18% or so when you reach your final tune. Where did you end up with your FT's on the low throttle table?

[weith1111]

FT's on the LT table are like +3 ish I believe. Brought me pretty much spot on 100%

I figured I was headed in the wrong direction, but it's counterintuitive to see knock and reduce fuel.

[spyderturbo007]

FT's sound good, what are your Lo-throttle correction values at 1k, 2k, and 3k?

Originally Posted by weith1111

I figured I was headed in the wrong direction, but it's counterintuitive to see knock and reduce fuel.

Exactly and it's also dangerous!

That is why we want to take this slow and make sure "all of your ducks are in line" before you start making pulls again.

[weith1111]

Correction values? As in what is the AFC set at? I'm 99% sure they are:

1k 6%
2k 4%
3k-7k 3%

[1LE]

Originally Posted by weith1111

FT's on the LT table are like +3 ish I believe. Brought me pretty much spot on 100%

I figured I was headed in the wrong direction, but it's counterintuitive to see knock and reduce fuel.

Well, knock can result from being wrong either direction. It's just normal that people are too lean (throw go fast goodies on the car, start with old baseline which is too lean now). Just like EGT. It only tells you "something is wrong", does not tell you what exactly

[andymoraitis]

I agree with 1LE's asessment 1000% It appears from the logs that what's being encountered is rich knock. Pulled timing in either direction can tell you that it's either too rich or too lean, but based on the AFC values, I'd bet on it being rich and drowing in fuel. What points to it being rich know beyond the AFC values, is that knock starts at the onset of boost, which would indicate she's overloaded on fuel. Looking at your changes from log 1 to log 2, making it rich killed even more timing and brought about more knock.

Just for kicks, pull your plugs and read them. That'll tell you which way to go with your tune. You may also want to invest in a wideband since that's the best way to discover your true A/F ratio.

Let us know what you find,

Andy

[weith1111]

Don't want to have 2 threads open on this, please see:

First log ever, looks good?, but feels weak!