Dual TBI units - How To Handle Twin IAC's?

[Walter Sherwin]

Perfect timing for this discussion thread..........

Just days ago I ordered a brand new 454SS TBI unit from GM (17112570 aka
17091047),  to feed the second of two screw-chargers that will live together
atop my 454.    I'll be converting both TBI units for 30psig fuel pressure
operation (17113079 regulator),  in order to feed the peak airflow
requirements, and I intend to control both TBI's simultaneously via the
stock 16147060/BAMY PCM  together with an external  2-to-4  4/1 amp P&H
current driver box.

At this point everything regarding the project has been planned out in great
detail,  EXCEPT for the twin IAC issue.  I am still in the midst of "head
scratching" as to what I will do about this.  I could cheat, and just drive
one IAC via the PCM, but,  I would prefer to drive both IAC's via the PCM
for mixture and pressure balance reasons.  Here's what I am
wondering............

1) Can I physically drive two IAC's from the single PCM IAC driver?
2) If so, should I wire the two IAC's in parallel?
3) For a first blush at the cal, can I simply cut the commanded IAC steps in
half?  Just looking for a starting point.
4) Any other thoughts or recommendations?


Thanks a bunch;
Walt.