ECM Selection

[Bruce Plecan]

Before thinking about which one you need, might stop, to think though what
your doing.

In general.
There is lots of info. on the following:
1227148
1227165
1227730
1227747
1227749
1227808

The 148,  6cyl  SEFI  MAF  DIS  Turbo  (jury out about NA tables lining up)
165/808   4-6-8 cyl  MAF/MAP  Dist/DIS
730  4-6-8 cyl MAP/MAF Dist DIS
747  6-8 cyl MAP Dist
749  4-6 cyl MAP Dist  Turbo

 On the 148, I haven't seen or heard of anyone using that other than on a Bk
v-6
   pretty much as is.  C-3
The 165 as the ARAP v-8 has info. floating about, in the 808 version there
are
  supposedly 2-3 bar MAP versions in Oz.  P4/C-3  (808 C-3 ALDL)
The 730 as AHNT v-8 MAP has info floating around.  P-4
The 749 as v-6 turbo has a fully documented editor available for $15.  P-4
The 747 is a C-3 that has some info floating around.

There are some tools for using the 148, and getting some data from the ecm
or
from inside the ecm.
C-3 using diacom, are lacking in info, available from the ALDL
P-4 using diacom, give you a pretty good handle on what the ecm is thinking.

MAF or MAP just infer how much air the engine is using, both get converted
to grams/second, so the "direct reading advantage" is mute, IMHO
MAFs are more expensive than MAPs.
MAFs suffer from reversion, and delays in foil/wire changing temps, slight
but there.
MAPs have to have the filtering closer to right.
GM makes it decision based on millions of cars and federal mandates, so
using their example for selection is fine, if your going to build a couple
million cars.

The 730 (256K prom) has 2x the room for PID.
The 747 allows for an open loop idle.
No one has cross trained an ecm from DIS to Dist without external hardware
The 749 can do Peak+Hold for four injectors, in oem form.
You can run 749 code (with appropriate changes) in a 730, but lose wastegate
control..
What ever you do you will be right..  If you think it won't work it won't.
If you make an uninformed decision, your results will suffer.
Beleive dam little of what anyone tells ya, getting the knack for doing ecms
right takes alot of work.  Key word is right.

All you have to have is a DVM, a timer, a notebook, a ecm+car, and
promburning/erasing equipment.  An emulator/editor is nice but not a have to
have.
Simplicity is the key to design.
Being resourceful can save $$$$..
To make a better informed decision you ought to read the entire archives 2
or more times, IMHO
Bruce