I've spent a few months researching air intakes for my N55 (I know they don't add noticeable HP, but I like the look and sound) and finally came up with my ideal system. I hope this gives you all a new option to consider.
What I didn't want:
-A drop in high flow filter, no sound improvement and no need for more airflow.
-A shorty intake that's open to the hot engine compartment.
-A $500+ full intake system.
-An oiled filter of any kind since I have had to spend hours cleaning out intake manifolds and sensors that get gummed up.
My solution:
-Created a saved search for K&N 63-1132 on eBay that sent email alerts when a new intake was listed. This intake has a seal that presses against the hood preserving the cold air intake function. They are $250 brand new.
-Removed the oiled K&N filter and took measurements.
-Found the closest AFE Pro Dry S filter (AFE P/N 21-90054), $90 new.
-Installed the K&N intake on my N55 and the Pro Dry S filter bolted right up. It doesn't have as much surface area as the K&N filter, but I'm okay with that. I'll rotate it 180 degrees every 5-10k miles and wash it when needed.
