RevC 07/15/13
Page 30
attempt
to
add
enough
fuel
to
hit
the
target
AFR.
Note:
The
calculated
LambdaTarget
influences
the
fuel
delivered
to
the
engine
at
all
times,
even
when
closed-loop
02
feedback
is
disabled.
The suggested
tuning
method
is
to
set
the
AFR
using
the
LambdaTargetTable
or
AFR
Target
Table
to
a
value
safe
and
suitable
for
the
engine.
For
normally
aspirated
engines
a
value
of
13.0:1
or
0.887
lambda
is
usually
sufficient
at
all
operating
conditions.
For
boosted
applications,
the
operating
conditions
dictate
a
safe
AFR.
Please
consult
a
tuner
knowledgeable
in
your
engine’s
requirements
for
help.
Once
the
target
lambda
(AFR)
values
are
chosen,
run
the
engine
at
as
many
operating
conditions
as possible
and
adjust
the
VE
Table
to
reach
the
AFR
Target
Table
values.
Once
the
VE
Table
has
been
tuned
to
accurately
reach
the
AFR
Target
Table
values
at
all
operating
ranges,
then
you
can
change
the
AFR
Target
Table
to
use
different
AFR
settings
later.
Never
adjust
VETable
to
run
a
different
AFR,
only
to
achieve
the
LambdaTarget
value.
The
Injector
Flowrate
is
very
important
in
determining
the
fuel
requirements.
The
Infinity
ECU
uses
actual
Injector
Flowrate
[cc/min]
to
determine
the
proper
injector
pulse
width.
The
InjFlowRate
[cc/min]
table
is
calibrated
from
the
Setup
Wizard:
Injector
Flow,
however
the
table
can
be
modified
manually
for
unlisted
injectors.
Now that
the
base
injector
flow
rate
has
been
determined,
the
Infinity
ECU
applies
a
few
more
compensating
factors.
Wall
Wetting
is
a
function
of
fuel
condensing
in
the
intake
manifold
at
the
injection
point.
At
different
rates
of
change
in
the
MAP
[kPa]
values,
and
at
different
Coolant
Temperatures,
fuel
enrichment
compensations
are
used
to
prevent
lean
and
rich
conditions
during
rapid
manifold
pressure
changes.
The
WallWetting
2-
axis
table
can
be
adjusted
to
create
a
smooth
fuel
response.
Note
that
this
table
has
several
different
functions.
It
can
be
used
for
dynamic
transients
by
nature
of
its
“MAP
Rate”
x-axis.
It
can
also
be
used
for
more
steady
state
compensations
by
adjusting
the
values
in
the
“middle
band”
of
the
table
where
MAP
rate
changes
are
very
small.
Positive
numbers
in
this
table
will
effectively
add
fuel
to
enrichen
the
mixture.
Negative
numbers
have
the
opposite
effect.
