749 question(s)

[Dig]

> Date: Wed, 27 Sep 2000 08:39:49 -0400
> From: Barry Tisdale <btisdale at cybersol.com>
> Subject: 749 question(s)
> 
> In the SyTy ECM, anybody know the difference between
> the DESBOOST item
> (data stream #46) and the DBSTBASE @ #51?  Seems one
> or both of these would
> reflect what boost is wanted at a particular TPS/RPM
> value from the data
> tables, but neither seems to track this.

The way I've always understood it was as follows:


DBSTBASE    EQU $00b0

Desired boost base from table, no corrections applied.

BSTPRESS    EQU $00bc

Active Boost Reading, MAP - Baro.

DESBOOST    EQU $00bd

Current desired boost, including corrections for 
knock retard boost reduction.

So, the only time the two would differ, would be
if there was knock present. In reality, for the vast
majority of the Aftermarket cals out there, it isn't
enabled, so it doesn't work.

It's a Very Good Thing(tm) to have working, once you 
get everything dialed in correctly. Set it up to pull
boost back 20% when you get over 6% of knock, and it
saves your bacon when you've forgotten to put good gas
in.

As far as the not tracking RPM/TPS goes, I suspect
it's
a matter of using the right TPS and RPM variables,
scaled properly. Note the code:

                            LDX   #F70B
e5c9 d653                   LDAB  NTPSLD
e5cb 54                     LSRB  
e5cc c900                   ADCB  #$00
e5ce 9646                   LDAA  NTRPMX
e5d0 44                     LSRA  
e5d1 8900                   ADCA  #$00
e5d3 bdf5e6                 JSR   $f5e6  ;3D table
e5d6 97b0                   STAA  DBSTBASE

Hope that helps...


Later,

Dig
turbodig at yahoo.com
<insert Pretenders bass lick.wav here>
See y'all Saturday...


__________________________________________________
Do You Yahoo!?
Yahoo! Photos - 35mm Quality Prints, Now Get 15 Free!
http://photos.yahoo.com/
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org