The only way typically to see any type of intake results is to also have a sufficient free flow exhaust. They work hand and hand, the new free flowing exhaust sort of creates a vaacum on the free flowing intake, causing a nice free flowing system. I still dont see the gr8 of improvments with mine, but it sounds amazing, and thats all I care about really. When I lay on the pedal, the intake sounds like a turbo charger, so it be up to you, but if you dont plan to open up the exhaust, then you only be getting half way there with the results you are looking for, but it gets down to preference, it wouldnt hurt to have the K and N, but u also dont need it either