A
Haltech
MAP
sensor
(manifold
absolute
pressure)
provides
instantaneous
pressure
information
to
the
electronic
control
unit
(ECU)
from
the
intake
manifold
-
the
amount
of
boost
or
vacuum
in
the
intake
manifold.
This
is
necessary
to
calculate
air
density
and
determine
the
engine's
air
mass
flow
rate
or
in
other
words
engine
load.
Engine
load
is
used
as
a
reference
for
all
base
fuel
and
ignition
maps.
1
Bar
Map
Sensor
A
1
bar
MAP
sensor
is
capable
of
reading
intake
pressures
below
or
equal
to
atmospheric
pressure,
for
this
reason
a
1
bar
MAP
sensor
is
suitable
only
for
naturally
aspirated
engines
(ie
not
turbo
or
supercharged).
2
Bar
Map
Sensor
A
2
bar
MAP
sensor
is
capable
of
reading
intake
pressures
up
to
1
bar
of
positive
pressure
above
atmospheric
(otherwise
known
as
boost).
This
is
equivalent
to
around
14.7psi
of
boost
or
100kpa
of
positive
pressure.
This
sensor
is
suitable
for
turbocharged
or
supercharged
vehicles
running
15psi
of
boost
or
less.
3
Bar
Map
Sensor
A
3
bar
MAP
sensor
is
capable
of
reading
intake
pressures
up
to
2
bar
of
positive
pressure
above
atmospheric
(otherwise
known
as
boost).
This
is
equivalent
to
around
29.4psi
of
boost
or
200kpa
of
positive
pressure.
This
sensor
is
suitable
for
turbocharged
or
supercharged
vehicles
running
between
15psi
and
30psi
of
boost.