The cold air intake may add 5-10 hp to the 335 it was built with.
It depends on the intake that you get. There are short ram air and cold air intakes. Cold air intakes are preferred amongst rsx enthusiasts because of the cold air that is being sucked into the motor. On average, about 3-14 HP can be obtained from an intake. The quality and type of intake is what makes the difference between a lot and a little HP.
K&N states 11.83 hp gain @ 4248 rpm
15 hp
Just a few, probably 6-8 hp
between 10-15 HP
idk exact specifics, but after installing mine there is a definite notice in increased hp. i strongly suggest the cold air intake.
Headers may add 3-5 hp depending on design and a cold air intake will add around 4-7 hp for a total gain of 7-12 hp untuned. Definitely worth it especially with the nice throaty sound you will get out of it.
depending on the style of intake, and type of car you can gain up to around 20% hp
12 - 17 hp
Cold air intake, nitrous 75 hp system. exhaust, don't forget to beef your tranny, add a transgo shift kit.
5- 10 hp depending what is done to the car