Had the evening off work the other night so thought I would do a little work to my 159.
I had a cone filter from a previous car and it has just been sitting in a box so thought id see what its like on the 159.
Took the bumper off, pretty easy to do, although you have to pull quite hard to get the wings to release. I ended up cutting a section of the air intake pipe at the bottom so as more cool air will reach the filter. Took the little plastic guard off the bumper to allow more air in also (Does anyone know if it is meant to protect anything important?).
So, I got the old filter out and had a look at it! Im not an expert but I'm pretty sure that a filter that looks like this one is going to restrict the engine in some way!? Obviously hasn't been looked at for the 87k the car has done!
I used some piping from an old Bora a friend is breaking to extend the pipe down a little so it was easier to fit the filter. Worked a treat! I also cable tied it up a bit to help support it all. Feels pretty solid. The wheel arch liner is broken so I have a temporary fix until next week when I get my new liner to stop any dirt getting in.
Take a look at the video, Alfa 159 2 4 Air Filter (Induction Noise) - YouTube
I am amazed at how much it actually sucks! The sound when I come off the power is almost like a dump valve!
Anyway, I know there are a lot of people wondering if you can put a cone on the 2.4 so the answer is yes. Hope this helps.
On another note, I had broken the boot rams a while ago (for the 2nd time) so the boot was coming the whole way back and hitting the back window. I also fixed this problem, I took the rams off the Bora and they fitted perfect onto the 159. They are so much better than the Alfa ones as they slow the boot lid down so much more. They won't be breaking again!