Car Tuning Engine Performance Principles 2

Question 1

What does volumetric efficiency (VE) measure in an engine?

Accepted Answer

The ratio of actual air charge to the theoretical maximum the cylinder can hold

Answer

Volumetric efficiency is the ratio of the actual air-fuel mixture drawn into the cylinder versus the cylinder's theoretical maximum volume.

Question 2

Which camshaft specification most directly affects the engine's peak power RPM range?

Accepted Answer

Valve lift and duration

Answer

Valve lift and duration determine how long and how far the valves open, directly setting the RPM range where the engine makes peak power.

Question 3

What is the primary purpose of a high-flow catalytic converter in a performance build?

Accepted Answer

To maintain emissions legality while minimizing exhaust restriction

Answer

A high-flow cat uses a less restrictive substrate to reduce exhaust backpressure while still meeting emissions standards.

Question 4

What causes detonation (knock) to occur in a gasoline engine?

Accepted Answer

Uncontrolled auto-ignition of the air-fuel mixture before or after the spark event

Answer

Detonation occurs when heat and pressure cause the air-fuel mixture to self-ignite uncontrollably, creating damaging pressure spikes.

Question 5

How does increasing compression ratio affect an engine's octane requirement?

Accepted Answer

Higher compression increases the octane requirement

Answer

Higher compression ratios create more heat and pressure in the cylinder, making the mixture more prone to detonation and requiring higher-octane fuel.

Car Tuning Practice Test

Car Tuning Practice Test

Car Tuning Engine Performance Principles 2