Large throttle bores are preferred because of the turbulence they create.

Large throttle bores are preferred because of the turbulence they create.

• A. True
• B. False
• C. Depends
• D. Not applicable

Answer: (B)

The key idea here is how throttle bore size affects air velocity and the resulting turbulence in the intake charge. A larger throttle bore can pass more air, but it also lowers the velocity of that air at a given flow rate. Turbulence and the mixing it aids are enhanced by higher air velocity and by the flow geometry that creates swirls and vortices, which are more readily generated with smaller bores. So, large throttle bores don’t inherently create more turbulence; in fact they tend to reduce it at part-throttle and idle conditions. The main benefit of a larger bore is greater potential airflow at high rpm, not increased turbulence. That’s why the statement is false.

The key idea here is how throttle bore size affects air velocity and the resulting turbulence in the intake charge. A larger throttle bore can pass more air, but it also lowers the velocity of that air at a given flow rate. Turbulence and the mixing it aids are enhanced by higher air velocity and by the flow geometry that creates swirls and vortices, which are more readily generated with smaller bores. So, large throttle bores don’t inherently create more turbulence; in fact they tend to reduce it at part-throttle and idle conditions. The main benefit of a larger bore is greater potential airflow at high rpm, not increased turbulence. That’s why the statement is false.