Scanning E99 and get weird KR

I'm just scanning but not tuning right now.
It's a '19 ZR1 auto.

I've been trying to learn how much octane booster or 100-oct racing gas to mix with 91-oct pump gas to keep the LT5 out of KR.

I get some strange scan data.

In fourth gear runs uphill from 1500RPM to the rev limiter, I see a fairly significant KR "hit" but, in the spark reading, I don't see the same about of spark pulled. This problem is consistent.

For example, on one run, I had a KR spike to 4.9? at 6270RPM which stepped down to 4? at the 6600RPM rev limiter then to zero yet, the spark stayed almost the same the whole time between 19.0? and 19.8?

Seems to me with 4-4.9? KR it should have been at 14.9?-15? during that KR incident.

Any ideas?

I wouldn’t worry about it honestly... pretty normal for gen 5s to do This.

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Originally Posted by Ben Charles

I wouldn?t worry about it honestly... pretty normal for gen 5s to do This.

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It's normal for the E99 to report KR but not show that KR in the regular spark data?

Then, which is the correct data? The KR or the spark?

I was just able to track down the source of some similar phantom knock I was seeing on my C7Z, with the help of some guys on here. Look at the static retard table. On mine the cylinder labeled #1 was pulling up to 5 deg. This was showing up as KR in the logs. I've just recently zero'd that table out and am working on dialing in the timing now. Others, much more experienced than I, suggested cutting those values in half. I'm logging advance and retard on each individual cylinder while I try to figure this thing out.

Quote:

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Originally Posted by Prop Job

I was just able to track down the source of some similar phantom knock I was seeing on my C7Z, with the help of some guys on here. Look at the static retard table. On mine the cylinder labeled #1 was pulling up to 5 deg. This was showing up as KR in the logs. I've just recently zero'd that table out and am working on dialing in the timing now. Others, much more experienced than I, suggested cutting those values in half. I'm logging advance and retard on each individual cylinder while I try to figure this thing out.

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I'm not trying to change the calibration. At this point in time I cannot afford the hardware modification, the credits nor the loss in warranty coverage.

What I'm trying to do is simply understand what I'm seeing in data logs, ie: nearly 5-deg. of KR but no practical change in the delivered spark timing.

Mine was happening above .4 g/cyl up to 5200 rpm, the exact location of the static retard on cyl #1. Look at Spark-Retard-Static Retard-vs Cylinder. Log advance on each cyl and I bet you'll see one cyl dropping off in that range, if its anything like the C7Z.

I'll check that.
Thanks.

I've decided that the problem is that the E99 does not report "total" spark timing, ie: SAE spark or base spark less any KR.