multiple ECU/EFI q?

Fri Nov 6 16:25:09 GMT 1998

here is what I want to do

I have a 16 valve 4 cyl DOHC with 8 ex and 8 intake ports
I want to set this up with a split personality

I am going to port exactly 1/2 of the intakes and ex ports for
high end power including installing the largest valves that will fit

the other 1/2 of the ports are going to be optimized for low end, simple 
cleanup with stock sized valves and 3 or 5 angle seats

the intake manifold will have 2 sets of runners, 1 set long small tube for
low end torque, the other shorter with larger tubes for power

possibly dual mismatched MAF sensors and throttle bodies
and a progressive throttle body on the higher power side that 
starts to open at approx 3/4 opening of the low power side with both reaching
full open at the same time

engine layout looks like this

II  II  II  II
EE  EE  EE  EE

the large sets of ports will be directly below each other ( I am thinking that
tangential flow in the cyl will promote better swirl, but cross flow may 
increase the chance of getting fresh charge near the plug and help with
emissions. opinions??)

the exhaust header setup will be 2 completely separate
4 port headers optimized for low and high RPM individually
with 2 completely separate ex systems using appropriate sized tubing
probably sized at about 1.5 and 2.25/2.5"

MPFI will use 2 diff size injectors mounted 1 each to the intake ports and
sized to max airflow in each port

do any of the V8 ECMs have the ability to separate into 2 banks that are
completely independant as far as pulsewidth, EGR sensing, TPS, MAP, MAF etc.
or would this work better using 2 separate ECUs

with dual ECMs only 1 will have to operate the timing so the other could have
the same spark table with the output to a readout device that would show
spark timing or the tables could be fixed so that the steps are much smaller
and the 2nd ECU takes over timing at a certain RPM (this would obviously
require a slight RPM overlap to avoid a momentary cutout)

any suggestions

Clive 