Cessna TR182 1979 Pilot Operating Handbook page 154

SECTION 7
AIRPLANE
&
SYSTEMS DESCRIPTIONS
CESSNA
MODEL TR182
excess of 31in. Hg. In order not to exceed the maximum, manifold pressure
should be monitored closely and the throttle control adjusted as necessary
to maintain 31 in. Hg. if maximum continuous power is desired. Full open
throttle control will not be necessary to maintain maximum continuous
power (31in. Hg.), with the possible exception during hot day conditions at
high altitude.
MANIFOLD PRESSURE VARIATION WITH ENGINE RPM
The turbocharged, carbureted engine will react just the opposite of a
normally aspirated engine when the RPM is varied. That is. when the RPM
is increased, the manifold pressure will increase slightly. When the RPM is
decreased, the manifold pressure will decrease slightly.
MANIFOLD PRESSURE VARIATION WITH ALTITUDE
Manifold pressure will vary with altitude similar to a normally
aspirated engine. Manifold pressure will decrease with altitude unless the
throttle control is advanced. The turbocharger has the capability of
maintaining in excess of the maximum continuous manifold pressure of 31
in. Hg. Since the waste gate is manually controlled, the throttle control will
have to be advanced as necessary to maintain the maximum (31in. Hg.) or
cruise (25 in. Hg.) manifold pressure during climb.
MANIFOLD PRESSURE VARIATION WITH AIRSPEED
When the compressor side of the turbocharger is provided with a larger
quantity of air at the intake, as with an increase in airspeed, the manifold
pressure will increase slightly. When airspeed is reduced, manifold
pressure will decrease slightly.
MANIFOLD PRESSURE VARIATION WITH MIXTURE
Any change in mixture setting will result in a corresponding change in
manifold pressure. That is, enrichening the mixture will increase the
manifold pressure and leaning the mixture will decrease the manifold
pressure.
MOMENTARY OVERSHOOT OF MANIFOLD PRESSURE
Since a full throttle control position is not required for normal
operation, except possibly at high altitude on a hot day, the engine can be
overboosted slightly above the maximum continuous manifold pressure of
31 in. Hg. This is most likely to be experienced during the takeoff roll or
during a change to maximum continuous power in flight. The compressor
discharge pressure relief valve will normally limit the overboost to 2 to 3
inches.
?,-M
1 October 1978