3800 SC Knock Retard Decay and Attack Tables

[0069GTP]

These are tables that I don?t understand the logic of what the tables mean. Which makes me hesitant about making changes, especially since monitoring the effects may not be easy. And I'm not able to do any searching that seems to help.

One think I noticed when looking at a stock tune file and some others, 1) DHP tune (verified from my old DHP 1.0 PCM 2) ZZP file (unverified as ZZP) 3) Overkill file (unverified); is the KR Decay High Load table values are all lower that what is listed as the value range in HPT (256 - 62,540).
Stock - has 136 for 0 and 400 RPM cells, 23 in 800 - 2,400 RPM then 36 for the remaining RPM cells
DHP - has 136 for 0 and 400 RPM cells and 113 in the remaining RPM cells. ZZP looks the same (If it is a ZZP tune file)
Overkill - has 136 for all RPM cells

I have noticed that most tune files that I have seen have all grown from a DHP tune file as I see a lot of the same values in most parameters.
So, I was going to copy over the DHP values to my tune file in HPT, but I get the warning that the value is outside the min\max limits and even if I select yes I want to override the default parameter limits, it still populates the value with the minimum value of 256.

Anyone have any helpful insight to this issue of working with any of the KR Decay and Attack tables?

Thanks!!

[Rickisrad]

for some reason that HPT hasn't answered yet the Knock decay tables will not adjust properly. Many people have asked and they have not fixed or replied about it.

[0069GTP]

I emailed support and they created a support ticket, I emailed them a VCM info log file and a tune file. They responded today letting me know that there is a new 3.7 beta version of the software available to download from the customer page.

I will try this tonight or tomorrow and update the support ticket with the results. Maybe this will be fixed in 3.8 release.

[MMGT1]

I'm from the old days with the 6's. How I always handled these was to double the decay rate and remove half the KR until you have it under control. When you double the decay rate it does not affect the vehicles ability to react to the event, it allows a faster transition back to normal timing tables. If it detects KR coming back to normal, it'll pull timing again. You can reduce the Base a little as well as the 6s are generally insanely sensitive to Knock being a fluid based sensor. But, that is not necessary IMO. Double the decay rate and use the scanner to find any KR, remove half of what is reported in the cell right before it showed in the scan, and smooth adjacent cells. Repeat until KR is non-existent...

[ZeroBoostBuick]

Looking back at my old 3800 tunes I had....

Knock Retard Decay:
High Load = 136
Low Load = 400

Knock Retard Attack
Base Retard = 4.000

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With my tables the knock decays faster but still safe... Had it that way on 2 different 3800 cars.