Only reason I ask is I had a wrx before my evo 9 and cobb tunning said the factory filter breaths better for the rex. I was wondering if the same goes for the evo or not?

 

You'll get some gains for a drop in but it wont be very high

Since the drop is so cheap its usually worth it anyways

 

I beleive its something like 4hp

 

I didnt notice any power gains, but the dv got louder a bit. Im not saying you wont pick up a couple HP, but you wont feel anything.

To me, Id rather just buy new filters than have to clean and oil ones over and over again.

Plus, when I put the K&N in my car, a few months later I sent my oil in for analysis. It came back saying that my air filtration was poor and was contaminating my engine a bit. Sure enough, I could see some dirt and deposits inside the airbox that were not there before. Also some dirt on the inside rubber part of the filter that should be clean. Never had that problem before the K&N, and hopefully it will go away since I'm back to stock filters.

 

Ams did a test on this and the stock one flows better then the k+n. Get a blitz or hks.

 

I also have been researching this. It looks like the Works drop in is the best one out there in quality and filter surface area, but at a price.

 

nm

 

Don't over oil it :<