How do they get little jets of air to shoot out from under the hood In The Fast and the Furious?

Question

In the movie the main character's car pulls in to a pre-race display and as he is revving the engine there are little jets of air that shoot out from under the hood in two places. How is this achieved? Is it via blow off valves from a supercharger or just a movie stunt?

Answer 1

Purging the Nitros to relieve pressure

Answer 2

nitrous..purge

Answer 3

i d know

Answer 4

yes this possible in real life

Answer 5

It's called a Nitrous Purge.

It's part of an NO2 system to expel trapped gas so you can get a clean smooth nitrous blast when you need it.