mas sulit yung HP gains mo if you couple your aftermarket air intake with after market pipings and exhaust systems e.g. performance headers, larger diameter exhaust pipes and a freeflow muffler.

a good 8-10 hp gain siguro yan. although you wouldn't know the exact figure unless you have your car dynoed.

may thread dito dati comparing the dyno figures of a car with simota vs k&n filters eh.