Custom Program for a factory computer

[Roger Heflin]

On Fri, 22 Oct 1999, Eric Aos wrote:

> Has anyone written a complete program for the factory hardware?  It
> seems that the registers are pretty well figured out for some of them.
> How hard could it be to convert say the program for EFI332 to run on the
> GM Processor? is there a C compiler available? It would give all the
> benefits of proven hardware, and complete flexibility for those that
> just need to control Injectors, and Ignition. Perhaps the best of both
> worlds, would be to run a multi-chip, with a tweaked stock program for
> daily driving, and full race code for Sunday?
>  
> 

There is really no point to doing this.   The code will really work
for both as it is.  There are a few adjustemnts that I made to mine to
do things the stock program code was not designed to do, but figuring
out what GM's code is doing and adding small patches to improve things
is much easier than writing one from scratch.  The stock computer
already changes how it acts when you go wot, so you can already call
that "race".

C code would really not work.   Until you get to the later computers
(94+ or even later) there is really not enough address space to even
attempt to use a compilter for the job.  My car as a total of 32KB for
the eprom, and 8KB of that is the data (VE,WOT fuel,timing...).

The things I added to mine are:

Multiple fuel tables (one per gear-unknown if it buys me anything).

Added extra code to improve the way block learn/integrators interact
that speed up the computer getting the mixture when the VE numbers are
off.

Change a instruction to make the computer completely ignore block
learns at WOT (it would run things richer at wot if the BLM's said to)

Added code to lockup the TCC in 2nd gear at WOT (this gave me about 3
more mph in 2nd gear).

Really within what the limits of the stock computer system I really
cannot see what one of the aftermarket computer would even buy me over
the stock after you figure out everything you can adjust.

My car is a 93 Z28 LT1, and the computer is used in the 92-93 LT1
engined cars (camaro/firebird(93) and vette (92-93)).

			Roger