Talk:Hood scoop

can someone please explain why cool air would result in increased pollution? Isn't any engine more efficient when it's cooled down?

Automobiles only?
Motorcycles also can have hood scoops: Je suis Nigérian (talk) 22:38, 20 August 2016 (UTC)
 * https://www.choppertown.com/blog/bike-builder-episode-2-diesel-motorcycle/
 * http://www.jcwhitney.com/hood-scoops/suzuki-motorcycle-gs500/c2538d58770j1s21.jcwx

Naca scoops.
NACA scoops are unsuited for typical car uses. They need a velocity ratio of 0.6-0.8 to work at their best. Typical car cooling intakes are way lower than this. There are more efficient ways to scoop air. Notice how big car manufacturers never use them. They are popular in cars simply because they look cool or because people do not understand them. Read the NACA report on them. I suggest the article be edited to reflect their actual performance. Pictsidhe (talk) 20:16, 9 July 2020 (UTC)
 * I'm unsure what is meant by velocity ratio. This paper on NACA inlets from 2016 mentions: "velocity ratio defined as the ratio between the flow velocity at the duct entrance and in the free stream. A transition is observed between a quasi-laminar flow at a velocity ratio of 0.8 and a turbulent flow at velocity ratios of 0.6 and 0.4." Hopefully someone can fill in with what that means. I guess the question is at what speed does a NACA scoop become effective, i.e. on a car? Sauer202 (talk) 21:34, 6 December 2020 (UTC)