Deck 18: Turbochargers and Superchargers

Question 1

Technician A says boost differential occurs when pressure is higher in either the turbine or the manifold. Technician B says negative differential is best for performance. Who is correct?

A)Technician A
B)Technician B
C)Both technicians
D)Neither technicians

Answer 1

D

Question 2

Turbochargers are driven by _____.

A)belt
B)coolant flow
C)exhaust flow
D)electric

Answer 2

C

Question 3

What are two common turbo scroll designs?

Answer 3

Two common turbo scroll designs are:
single-scroll (constant pressure)
twin-scroll (two-pulse)

Question 4

An internal wastegate is plumbed into the exhaust manifold.

Question 5

All of these are dynamic superchargers EXCEPT _____.

A)centrifugal
B)positive displacement
C)axial flow
D)pressure wave

Question 6

The maximum flow capacity of a turbo compressor is called "choke."

Question 7

An engine with a turbocharger is a normally aspirated engine.

Question 8

On carbureted engines, a _____ supercharger system pressurizes the air cleaner above the carburetor or fuel injection system.

A)flow-through
B)blow-through
C)draw-through
D)pumped-through

Question 9

What is an aftercooler?

Question 10

What characterizes a positive displacement pump?

Question 11

What is the area between the parallel walls of the compressor cover and bearing housing where the air leaves the wheel?

A)the inducer
B)the spool
C)the volute
D)the diffuser

Question 12

What is turbo lag?

Question 13

Technician A says a fixed geometry turbocharger requires pressure relief because it operates over a wide rpm band. Technician B says a wastegate is commonly used to control the speed of the turbine in automobile engines. Who is correct?

A)Technician A
B)Technician B
C)Both technicians
D)Neither technician

Question 14

Technician A says following turbo use, turbo bearings cool quickly when the engine is shut off. Technician B says synthetic oil burns at a lower temperature so it is the oil of choice for use with a turbocharger. Who is right?

A)Technician A
B)Technician B
C)Both technicians
D)Neither technician

Question 15

Turbo damage by a foreign object is being discussed. Technician A says to look at the valves to determine from which direction the damage came. Technician B says compressor wheel damage results from objects entering the intake stream. Who is correct?

A)Technician A
B)Technician B
C)Both technicians
D)Neither technician

Question 16

A properly working supercharger will increase the density of the air in the cylinder.

Question 17

Types of dynamic superchargers are being discussed. Technician A says the pressure wave is used mostly for two-stroke diesels. Technician B says a centrifugal supercharger is is crankshaft driven, rather than exhaust driven. Who is right?

A)Technician A
B)Technician B
C)Both technicians
D)Neither technician

Question 18

The turbine wheel and shaft assembled with the compressor wheel comprise the ____.

A)turbo housing
B)rotor
C)splitter blade wheel
D)radial wheel

Question 19

What causes the condition known as turbo surge?

Question 20

Because cast iron heads dissipate heat better than aluminum, they are the head of choice for use with a supercharger or turbocharger.

Question 21

All of the following are true about superchargers EXCEPT:

A)Superchargers are louder than turbochargers.
B)Superchargers run cooler than turbochargers.
C)Turbochargers spin slower than superchargers.
D)Lubrication is not as big a problem with superchargers as turbochargers.

Question 22

What is a turbocharger that pressurizes the intake manifold after the throttle plate called?

A)A draw-through turbo
B)A blow-through turbo
C)A normally aspirated turbo
D)None of the above

Question 23

Under high boost, when the throttle plate is closed quickly to decelerate, turbo _________ can occur.

Question 24

If a normally aspirated engine climbs to 3000 feet in altitude, how much power will it lose?

Question 25

An engine not equipped with a supercharger is referred to as a normally _______ engine.

Question 26

The rpm of the turbine increases about _______for every 1000-foot increase in altitude.

Question 27

Which uses power when cruising, a supercharger or a turbocharger?

Question 28

What is the name for the point at which boost first starts (1800 rpm, for instance)?

Question 29

An aftermarket blow-through turbocharger is often easier to fit under the hood. True or False?

Question 30

Another name for a lobe-type supercharger is _________ type.

Question 31

When an engine produces sufficient exhaust flow to spin a supercharger or turbocharger enough to create boost, this is referred to as __________.

Question 32

What is the name of the turbocharger wheel that is on the intake side?

Question 33

The time required to bring the turbo up to a speed where it can function effectively is called __________.

Question 34

The two most common superchargers in automotive use are the _________ and the _________ types.

Question 35

Approximately how much more torque and horsepower can a turbocharger provide over a stock normally aspirated engine?

Question 36

What is the name for a pump that delivers the same amount of air with each revolution regardless of the speed?

Question 37

What is the name of the relief valve used to limit turbo boost pressure?

Question 38

Technician A says that if a turbocharger wheel has been rubbing against the housing, the turbocharger must be replaced. Technician B says that a bad turbocharger can cause engine oil consumption. Who is right?

A)Technician A
B)Technician B
C)Both A and B
D)Neither A nor B

Question 39

Which of the following is/are true about turbochargers?

A)Turbochargers are usually called blowers.
B)A car with a turbo will not operate as well in high altitude.
C)Cooling the compressed air from the turbocharger by 100 $\degree$ F can increase engine power by 10%.
D)All of the above

Question 40

A power gain of about 1% is achieved for every _________°F that the air-fuel mixture is cooled.

Question 41

All of the following are true about turbochargers with full-floating bearings EXCEPT:

A)Full-floating turbo bearings have oil clearance on both sides.
B)A defective compressor shaft seal can also cause oil consumption and an intake manifold air leak.
C)The turbocharger spins at about one-third the shaft rpm of a supercharger.
D)A normal turbo shaft will feel loose.
E)A restriction in the oil return can result in oil consumption and smoke.

Question 42

If a supercharger provides 15 psi of boost pressure, this effectively doubles the engine size. True or False?

Question 43

If the __________ does not close when the intake side of the turbo is under boost, the crankcase can be pressurized.

A)Wastegate
B)PCV valve
C)Both of the above
D)Neither of the above

Question 44

Which of the following is/are true about belt-driven positive displacement blowers?

A)Heavy boost blowers use a cogged belt to eliminate slippage.
B)A cogged blower drive belt takes the place of a vibration damper.
C)All of the above
D)None of the above

Question 45

Which of the following is a name for the device used to cool supercharged or turbocharged air?

A)Intercooler
B)Charge air cooler
C)Aftercooler
D)All of the above
E)None of the above