Filter versus full intake kit

[FloridaE30M42]

does anyone know the numbers (HP and torque) gains of just switching to a high flow air filter in the stock airbox versus the gains in a whole neew intake system, such as K&N?

[gearheadE30]

Niether one will get much horsepower as the stock airbox is all that the 4 cylinder needs. A K&N panel filter is nice because they are reuseable and last forever. The full "cold air" intake only makes the intake sound louder. You can get the same thing for free by drilling out the sides of the airbox.

[christophbmw]

i have a K&N flat panel, no difference, i just got so i wouldnt have to buy a new one every 15K. Actually you will lose horsepower if you install a cone type if it is not a true cold air intake (ive seen dyno sheets), if you do get a cone filter make sure its a true "cold air" kit with a heat sheild and everything......you might get 1 or 2HP gain if it is a true cold air intake......but i dont think its worth it.