Focus Fanatics - View Single Post - K&N Drop-In/Stock Housing Lid
View Single Post
Old 09-11-2012, 04:29 PM   #8
jimfocus
Focus Enthusiast
 
Join Date: Sep 2009
Fan#: 69155
Location: Wrentham, MA, MA
What I Drive: 2012 Race Red Focus SE

Posts: 177
FF Reputation: 2 jimfocus Good Standing Member
Buy-Sell-Trade Rating: (0)
What I did was I bought a new air box lid (only about $6). I drilled a 3" hole in the front left with a hole saw. The hole faces front and lines up basically with the hood/fender gap on the drivers side, the grill/headlight area. I think cool air penetrates. I made a shield on the top front with 2" foam (like you use on your house windows to insulate an a/c unit). I have a K&N drop in with that. So there is a significant additional opening (bigger than the throttle body) but some heat protection and a little more sound. It is a little louder but not ridiculous and I think I notice a performance increase. It can be easily changed for dealership visit or inspection. I see recently there is a UK company offering a filter with the top end opened (which would be exposed on our cars) or the make an adapter ring that can be used with universal K&N type filters.
jimfocus is offline  
    Reply With Quote