'747 and Proportional Stuff

[Scott Lundahl]

There is a God.  Thank you - send more . .

I had a question about the "stoich" byte.  You say that it must match the 
O2 threshold settings which I assume means the very steep mV vs. AFR Lambda 
curve.  I have always theorized that it was used as in calculations where 
things are expressed in therms of AFR (such WOT fueling, cold enrichment, 
etc).  This byte tells the ECU what AFR the stored and/or derived values 
(and their associated bpw's) are supposed to represent (in a CL system this 
is almost always 14.7, but could be other values in an open loop 
system).  In this way a meaningful, dynamic bpw's can be calculated for 
other parameters expressed as AFRs.  Can you you explain more about it?

_scott

PS - I had to squeak the idle Prop gain up to 5, but other than that, the 
scaled Prop & Duration param's seem to be working much better.  BLMs are 
rock stabile, INT is a happy 128.  O2 cycle frequency much more 
respectable.   No surging.  It's Closed Loop Nirvana.

At 06:02 PM 7/10/00 -0400, you wrote:

>So, your cruising around in your newly setup gm-ecm system, smile
>on your face, tunes filling the interior, girl at your side, life
>doesn't get
>better. But wait, what's this? Engine seems to be running a little
>lean, even surging a little, hmm, I know that VE table is dead on,
>the 128 INT/BLM tells me so!
>
>Ah, grasshopper, there is much to learn.
>
>Need to control the closed loop AFR? Like to reduce the drastic
>swinging of that O2 sensor reading? Read on. . .
>
>On incoming: 747Prop.txt, describes the 'internals' (roughly), the
>inner proportional fortitude of a gm ecm. Yes grasshopper, someday,
>you too, will see.
>
>Having fun <g>,
>
>BobR.
>
>Coming soon to an ftp site near you, make your 'dumb', 747, 'smart'.
>Increased resolution of your VE% tables, rpm & mph limiters, MAP
>filters for that smooooth idle, more. . .
>
>
>
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