Factory Sierra Program

[12secSS]

I did a log of my 1999 Sierra to get an idea of what I need to adjust using HPTuners, prior to changing anything on the OE tune. Very interesting to say the least. The OE BIN file needs some serious attention to get it to perform decently, man what was GM thinking? Here are a couple of screen shots of the AF, LTFT and Advance table histograms from my morning commute. Not very good IMHO. I will be dynoing very soon to get a baseline, then I will try an work some 'magic' and redyno it to see the results. I may track test it as well, just for the heck of it.

 

Air Fuel Table Histogram

 

Advance Table Histogram

 

LTFT Table Histogram

[mjgjr72]

what was GM thinking?

probably emissions, and fuel economy

[12secSS]

what was GM thinking?

probably emissions, and fuel economy

 

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and being on the conservative side.

[dannyukonxl]

htats good and bad, at least their motors have a lot of potential to unlock, too bad they dont unlock it from the start, how about a 400 hp 5.3 450 hp 6 and a 500 hp 8.1 just like the old days