Black cover over radiator - what it hides?

[varum]

Can anybody explain me: what is located under this big black cover, which is over radiator?
Thanks.

 

[speed1016]

its basically mazdas cheap CAI. If you look close it is hooked to the intake. This brings in colder air from outside the car.

 

[peepsalot]

that's where they keep the vtec

 

[varum]

Thanks for the answer! May engine work without it, in general ?
Or CAI has some sensors, so it is necessary?

its basically mazdas cheap CAI. If you look close it is hooked to the intake. This brings in colder air from outside the car.

 

[speed1016]

nope it will work without. But it will take in hotter air.