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I did go through and compare some XDFs, in the three values we are concerned with here, max advance/retard and reference angle. And the forumulas were the same between them, the only difference being signed/unsigned for a couple of the values, and I did change those settings in the XDFs I had.
I can not vouch for the XDF's other than the max advance / retard settings. The formula that's typically wrong is max retard at 2.0000 * X + 0. The early $59 xdf is where I first discovered it. And it's no surprise since no one was altering those values significantly.
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The one thing that strikes me as odd, is the F28 in one of the XDFs you posted shows very different values, due to the conversion. It shows very small values, of less than one (decimal values) where other XDFs shows complete values, usually in the 130 and up range.
Is the F28 table showing low numbers in the RR definition? The F28 table has always had low numbers in TC software as well. I was surprised to learn most xdf's use a conversion which displays higher values. Here's a thread on thirdgen that shows low values in that table: http://www.thirdgen.org/techboard/di...-bpw-58-a.html Regardless, if you scale the values based on engine displacement and injector size you'll get the correct constant.
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Well, 1project2many says he had $58 running his DIS Sunbird years ago, so unless there was another change that he's forgot to mention, I'd think it should work. I can't imagine him driving around with locked timing.
I usually adjust the time correction to match DIS but that value has nothing to do with locked timing. The engine I used $58 on was actually a 2.2 powered Cavalier and I drove it for almost 5 years before it rusted out.
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i tested some of these codes years ago and a lot wernt good when changing reference settings for dis it would just lock timing due to hard coding in the bins not allowing changes if i remember right $59 had changes to allow dis changes
The timing code between $58 and $59 is the same. The only gotcha in the code is if your limit is greater than 90 degrees or less than -90 deg. There have been several issues with incorrect conversions, limits treated as 8 bit values, and limits being treated as unsigned integers. For many years I advented calculating the value by hand and using a hex editor to enter it manually but that method never caught on. Maybe for the same reason very few people use scientific view on Winnows calculator.
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think a lot of it was how the xdf's were setup back then and displaying different figures in different xdf's the joys of the diy community and multiple people making xdf's for different code bases.
Much good has come from open definition file development. Unfortunately, with no controls or no "authority" there are unknown number of incomplete, wrong, or just plain different files out there. Maybe you guys have an advantage in that respect with the limited number of Delco boxes available. I wouldn't be surprised if bad definitions for $58 are still surfacing in 2023.
