Car Tuning Aerodynamics and Body Styling 2 — Questions and Answers
Question 1: What is the primary purpose of a diffuser located at the rear underside of a car?
- Increase top speed by reducing drag
- Accelerate airflow exiting from under the car to generate downforce (Correct answer)
- Cool the exhaust system
- Redirect exhaust gases away from the body
Correct answer: Accelerate airflow exiting from under the car to generate downforce
A diffuser expands the underfloor airstream as it exits, lowering pressure beneath the car and creating downforce.
Question 2: Which body modification is most effective at reducing lift on the front axle at high speed?
- Front splitter (Correct answer)
- Hood scoop
- Side skirts
- Fender flares
Correct answer: Front splitter
A front splitter separates high-pressure air above from low-pressure air below, pushing the nose downward.
Question 3: What does a negative camber angle on the front wheels do to aerodynamic contact patches during cornering?
- Reduces the tire contact patch entirely
- Keeps more tire surface in contact with the road under lateral load (Correct answer)
- Increases understeer significantly
- Lowers aerodynamic drag on the wheel arch
Correct answer: Keeps more tire surface in contact with the road under lateral load
Negative camber tilts the top of the wheel inward so the tire remains flatter on the road when the body rolls during cornering.
Question 4: A canard wing mounted ahead of the front wheel arch primarily does what?
- Diverts airflow to cool front brakes and generates small downforce (Correct answer)
- Reduces overall vehicle weight
- Acts as a decorative element with no aerodynamic function
- Increases frontal area to slow the car on straights
Correct answer: Diverts airflow to cool front brakes and generates small downforce
Canards generate localized downforce and guide airflow around the front wheel arches, reducing turbulence and aiding brake cooling.
Question 5: In aerodynamic terms, what is 'flow separation' on a car body?
- The point where laminar airflow detaches from the surface and becomes turbulent (Correct answer)
- Splitting exhaust flow into two streams
- Dividing intake air between engine cylinders
- The gap between the body panel and the frame
Correct answer: The point where laminar airflow detaches from the surface and becomes turbulent
Flow separation occurs when the boundary layer can no longer follow a surface, creating turbulent wake drag.
Question 6: Why are some high-performance cars fitted with flat underbody panels (undertray)?
- To protect the drivetrain from road debris only
- To create a smooth surface that accelerates underbody airflow and increases downforce (Correct answer)
- To reduce ground clearance for visual effect
- To add structural rigidity to the monocoque
Correct answer: To create a smooth surface that accelerates underbody airflow and increases downforce
A flat undertray eliminates turbulence from exposed mechanical components, allowing consistent high-speed airflow that lowers underbody pressure and produces downforce.
Question 7: What effect does a vortex generator on a car roof have on aerodynamics?
- Increases drag intentionally to slow the car
- Energizes the boundary layer to delay flow separation on the rear window (Correct answer)
- Generates lift to improve high-speed stability
- Channels air into the cabin for ventilation
Correct answer: Energizes the boundary layer to delay flow separation on the rear window
Vortex generators create small rotating air spirals that re-energize slow boundary layer air, keeping it attached to the surface longer.
Car Tuning Aerodynamics and Body Styling 2
What is the primary purpose of a diffuser located at the rear underside of a car?