Piper Malibu PA-46-310P Pilot Operating Handbook page 250

PIPER AIRCRAFT CORPORATION
PA-46-310P, MALIBU
SECTION 7
DESCR/OPERA TION
manifold pressure. Accessories normally installed include one gear-driven
alternator, a propeller governor, two magnetos. an oil filter, an air/ oil
separator, a starter and one gear-driven vacuum pump. Optional accessories
include a second belt-driven alternator. a second gear-driven vacuum pump.
and a belt-driven air conditioning compressor.
Turbocharging is accomplished by two Garrett - A.I.D. turbo-
compressors. one located on each side of the engine. Turbochargers extract
energy from engine cylinder exhe,ust gases and use this energy to compress
engine induction air. This allows the engine to maintain rated power at
altitude. When engine induction ai,· is compressed by the turbocharger, the
air temperature is increased. The ele.vated air temperature is reduced by air
aftercoolers located on each side of t!le engine.
·1
his aids in engine cooling
and improves engine power and efficiency.
Each turbocharger extracts exhaust energy froin its respective bank of
cylinders to pressurize the induction air. Air flows through the induction
inlet louvers into the induction air box, where it is filtered and divided for
distribution to the left and right turbo compressors. At the compressor. air
pressure and temperature are increased. Pressure increases air density
making a greater mass of air available to d1e engine cylinders on each intake
stroke. Air then flows through an aftercoole~.here air temperature is
reduced, further increasing the density of air avml.able to each cylinder.
Downstream the aftercoolers. air flow joins at the ••y" junction of intake
tubes on the top front of the engine. then passes the throttle butterfly valve
and is divided to individual intake pipes flowing to each cylinder. Metered
fuel is injected into the cylinder head, upstre~m of the intake valve. After the
fuel burns in the cylinder, exhaust gases flow into the exhaust manifold and
then to turbocharger turbines where exhaust energy is extracted to drive the
compressor.
Turbo compressed air is throttled across the throttle butterfly valve as
set by the throttle lever. A sloped control system monitors pressure differen-
tial and uses engine oil pressure to automatically position the waste gate
valve. The waste gate bleeds excess exhaust gas from the exhaust manifold
crossover pipe and out the left exhaust stack, bypassing the turbocharger.
Thus the controller automatically maintains manifold pressure.
The engine is well protected against overboost damage from excessive
manifold pressure. The waste gate controller senses manifold pressure and
will continually adjust turbocharger output, maintaining the manifold
pressure set by the throttle. The controller automatically protects the engine
ISSUED: JANUARY 11, 1984
REPORT: VB-1200
7-3