Code changes
First off, each chip we burn has 2 parts to it, the software code, which contains all the algorithms for most everything our ECM does, and the calibration tables.  This was done by GM so that they could write up a software program, change only the lookup tables for calibrating an engine. This way they could easily fine tune a motor, or use an ECM/program on multiple motors/revisions. Promgrammer, Tunercat and so on ONLY edit the tables.  Everything that is shown on Promgrammer is considered the calibration section. There is a HUGE section of code before the calibration tables that consists of Motorola assembly code.  We have disassembled that, and dissected portions of it.  Changing information in the code is tricky, and holds a lot of potential.  Already we have changed the code for 3 bar calibrations; Dig has made use of a boost code change for MPH scaling. I've done a few goofy things with it as well....

What code changes exist?

Scaling the F71 table versus MPH rather than throttle. This is much more logical, because, who cares about boost control at lower throttle percentages? Versus MPH lets us try to account for boost spikes at TC lockup and shifts.

0x03E7 F71_TABLE Initial Value Of WG Duty Cycle vs Throt. Pos. 
%mph 0 10 20 30 40 50 60 70 80 mph
| 0.0% 12.5% 25.0% 37.5% 50.0% 62.5% 75.0% 87.5% 100% 
---------------------------------------------------------------
(%) | 39.8 39.8 39.8 39.8 39.8 50.0 60.2 64.8 68.8

In a hex editor, change locations 2538-2539 to 96 4E.  That will change your F71 table to read:

         0      32    64    96    128  160  192  224  256 MPH
(%) | 39.8 39.8 39.8 39.8 39.8 50.0 60.2 64.8 68.8

I believe, if you change 2538-2539 to 96 50, that will change the F71 to read:
         20    25    30   35     40    45    50    55     60  MPH  
(%) | 39.8 39.8 39.8 39.8 39.8 50.0 60.2 64.8 68.8

Which would give us even *better* resolution.

- BG -