Turbo charger

Question 1

Basic function of a turbo

Answer 1

utilizes exhaust gases and heat to drive a centrifugal air pump that increases air pressure of the air entering the intake manifold

Question 2

five other things a turbo can do for and engine

Answer 2

helps operate at higher altitude
increase power without adding weight
increases power without needing larger engine
compensates for varying load demands
reduced exhaust gas and increases fuel economy

Question 3

after cooler and intercoolers are used with turbo because

Answer 3

as air is compressed it heats up becoming less dense hot air must be cooled to get the best benefit from the increased air flow

Question 4

as a result of the increased air flow to the cylinders

Answer 4

you will get increased turbulence as well aiding in the combustion process

Question 5

difference of turbo over naturally aspirated

Answer 5

compression ratio is lower
cam and valve timing are changed to fully gain the benefits
injection timing is retarded
fuel injection pump out put or fuel injector size is increased
centrifugal fuel injection advance may not be required
crankcase vent could be vented to atmosphere

Question 6

power out put of a turbo charged engine

Answer 6

may be as much as 50% more

Question 7

turbocharger is often called a

Answer 7

centrifugal air pump

Question 8

a turbo charger operates in direct proportion to engine speed true or false

Answer 8

false

as the amount of engine exhaust heats up the turbo speed will also increases

Question 9

turbocharger components include

Answer 9

turbine housing , turbine wheel , compressor housing , compressor wheel

Question 10

turbine housing

Answer 10

used to direct hot expanding exhaust gases to the turbine wheel causing the turbine shaft to rotate
due to high temps on the exhaust tide housing must be heat resistant usually made from cast

Question 11

nozzle constructed of a series of veins is for

Answer 11

directing the flow of exhaust gas to the outer edge of the turbine wheel so it will receives constant force

Question 12

wastegates are used for

Answer 12

diverting some of the exhaust gas from the turbine wheel to help maintain safe intake manifold pressure

Question 13

compressor housing usually constructed out of

Answer 13

aluminium due to the lower heat on the intake side

Question 14

diffuser plate used on the compressor side used for

Answer 14

helps direct the boost air to the intake manifold

Question 15

why must the turbo charger get full oil flow right away

Answer 15

because when the engine starts up the turbo can reach high speeds soon after

Question 16

how do some turbochargers stop internal oil from pushing past the seals during normal operation

Answer 16

with a wind back seal

Question 17

why are piston rings used to seal turbo oil cavity

Answer 17

because of the high operating temps

Question 18

why must radial and axial movements be kept with in spec

Answer 18

because the turbine or compressor wheels may come into contact with the housing

Question 19

what must you do after running an engine with a turbo under loaded conditions

Answer 19

allow time for the turbo to cool down with system oil before shut down
a turbo that is cooled to fast may warp crack or have premature bearing failure

Question 20

blue smoke from an engines exhaust

Answer 20

engine is likely burning oil

could be from worn piston rings or oil might be leaking into the compressor side of the turbo and feeding the engine

Question 21

if the oil drain on the turbo was plugged

Answer 21

oil into the turbo could become pressurized and leak past the seals into the turbine or compressor housing

Question 22

what is an important step to take when installing a new turbo

Answer 22

pre fill the turbo with oil and spin by hand to ensure it will have proper lubrication before start up

Question 23

shut down procedure for turbo

Answer 23

run at half speed for 3 to 5 min
then idle for another 3 to 5 min
this allows engine oil to remove as much heat as possible before shut down

Question 24

why must you cover turbo exhaust during transport

Answer 24

because air flow over exhaust turbine could cause the intake side to turn and premature bearing wear could ensue

Question 25

where is the after cooler or intercooler usually located

Answer 25

after the turbo and before the cylinders

Question 26

air to air coolers can reduce the heat of incoming air from

Answer 26

135 to 160 down to 43 degrees

Question 27

why is an air to air more effective in cooling then a air to coolant

Answer 27

because the ambient temperature of the air moving through a air to air cooler is much lower then the temp of the coolant in the air to coolant system

Question 28

one clue to coolant in the intake manifold

Answer 28

white smoke out the exhaust

Question 29

why are waste gates and variable displacement turbochargers used

Answer 29

to control the amount of exhaust acting on the turbine to affect haw much boost or turbine speed you can have under various loads

Question 30

waste gate function

Answer 30

senses the amount of boost pressure in the system and allows a specific value of exhaust gas to bypass the turbine controlling your maximum boost

Question 31

two types of VDT

Answer 31

pivoting nozzle vain

sliding nozzle vain

Question 32

Sliding nozzle vain operation

Answer 32

air actuated linkage controls the sliding nozzle back and forth controlling the amount of backpressure acting on the turbo

Question 33

pivoting nozzle vain operation

Answer 33

air actuated vain open and close to controll the amount of exhaust gas back pressure acting on the turbine