Cessna T188C - Page 230

MODEL
188
& T188
SERIES
SERVICE
MANUAL
c.
The
air
and
fuel
mixture
is
burned
in
the
cylin-
d.
Cover
both
intake
and
exhaust
ports
to prevent
ders,
and
exhausted
through
the
risers
and
manifold
foreign
material
entry.
to
the
turbine
section
of
the
turbocharger,
or
through
e.
Disconnect
and
cap
oil
pressure
and
return
lines
the
preset
wastegate
bypass
as
previously
explained
at
turbocharger
connections.
Cover
oil ports.
in the
exhaust
system
section.
f.
Disconnect
the
inlet
air
temperature
probe
wiring
at connectors.
NOTE
g.
Remove
four
mount
bolts
from
turbine
inlet
mount
pad.
For
additional
information
covering
turbo-
h. To
install,
reverse
above
procedures.
charger
and
component
maintenance,
over-
haul
and
trouble
shooting
refer
to
the manu-
NOTE
facturers'
overhaul
manual.
If
throttle
body
was
removed,
reinstall
11B-53.
REMOVAL
AND
INSTALLATION.
(See
according
to
dimensions
in
figure
11B-4.
figure
11B-5.)
a.
Remove
top,
left
hand,
and
right
hand
sections
11B-54.
OPERATION.
The
turbocharger
is
capable
of engine
cowling
for
access,
of
producing
more
manifold
pressure
than
required
b.
Disconnect
duct
from
compressor
inlet
elbow,
for
maximum
power,
(39.
5 In.
Hg
at
sea
level).
and
hose
from
compressor
outlet.
Therefore
an
overboost
valve
is installed
in the
in-
c. Disconnect
clamp
on turbine
exhaust
pipe,
and
duction
system
just
prior
to
the throttle
body.
It is
pull
pipe
out
of
slip-joint
at
waste
gate.
adjusted
to
begin
unseating
at
38.
5 In.
Hg
and
will
allow
a
manifold
pressure
of 39.
5 In.
Hg
at sea
level.
4
1.
Left
Rear
Oil
Sump
Mount
Bolt
2. Bracket
3.
Rear
Left Oil
Sump
Mount
Bolt
4. Throttle
Parallel
to Oil
5.
Intake
Manifold
Connection
.
-
--
6.
Throttle
Arm
7.
Pressure
Relief
Valve
Mount
Adapter
Figure
11B-4.
Throttle
Body
Installation
Dimensions
the
adjusting
bolt
out will
cause
a decrease
in
mani-
CAUTION
fold pressure,
because
more
exhaust
is bypassed.
A
schedule
of
maximum
allowable
manifold
pressure
This adjustment
should
not be
changed.
If
versus
altitude
is
exhibited
in
the aircraft
cockpit.
a
in
thorough
trouble
shooting
it is
determined
and
is
as follows:
that
the
valve
is malfunctioning,
it
should
be
replaced.
Adequate
adjustment
is
provided
with
the wastegate
adjustment
bolt.
Density
Altitude
Maximum
Manifold
Pressure
The
intention
of this
system
is to
provide
the operator
with
a turbocharged
engine
with
normally
aspirated
Sea
Level
39.5
In Hg
characteristics.
i. e.
full
throttle
for takeoff.
climb.
and
other
flight
conditions
where
needed,
without
con-
2500
Feet
38.8
In Hg
cern
for
an
overboost.
5000 Feet 38.1 In Hg
A
wastegate
adjustment
bolt
is
provided
to
adjust
the
full
throttle
manifold
pressure.
Although
the
adjust-
7500
Feet
37.3
In
Hg
ment
is not
completely
linear,
an
approximation
of
1/8
inch travel
of adjustment
bolt
(3 to 4 turns)
causes
approximately
0.
5 In.
Hg
change
in
manifold
pressure
-
Maximum
Allowable
Manifold
Pressure
Turning
the
adjusting
bolt
in gives
an increase
in
manifold
pressure,
because
less
exhaust
gases
are
The
wastegate
adjustment
bolt
should
be adjusted
to
bypassed
through
the
wastegate.
Conversely.
turning
provide
full
throttle
manifold
pressure
in
accordance
with the
above
values.
11B-16