K&N or not
 

Hi folks:

I am a new owner of a 2003 AP1, 48,000 miles. I have a very limited history on the car, but as far as I can tell it is completely stock except for a K&N filer and intake. This is a daily driver, street car only. I am not one to clean my own filter, so it will need to be replaced at some point (not really sure how often). My question is should I keep the K&N or replace the filter and intake back to stock. I'm also missing the black filter housing. I think I would like the car to be "stock", but I may not fully understand the advantage of the K&N, so any advice either way is welcomed. Thank you in advance.

The K&N is ugly.

BUT probably makes a small amount of power.

Some people like the noise. B serious doesn't.

I prefer the stock box for looks and function.

I would suggest learning to love cleaning it. :D A replacement filter for the FIPK intake is over $100. The care kit is ~$10 and will let you clean and re-oil the filter multiple times (easily lasts all year). If you return to the stock box (not counting the cost of that), a replacement filter will cost $20-30 each time you replace.

As for power, not much at the top end. Gains are in the mid-range.

Water & washing powder in a bucket works well,

I have owned k&n on many cars and trucks over the years whether it be a drop in or a full intake and they really are not hard to clean. YouTube is a great resource and should build your confidence to clean. I found the only annoyance was waiting for it to dry. Otherwise advertise a swap for the stocks parts, likely someone near you looking to upgrade from stock.

I'd personally keep the intake. I love intake sound on all cars!

I had a K&N in the stock box few several years. I had a tendency to over oil it. I was concerned about getting excess oil going into the throttle body, so I gave it to a buddy. He eventually went back to a stock filter also. I've read that these filters may breathe a bit better, but are not as effective filtering dirt as an OEM filter.

Buy and use the cleaning kit. Don't over-oil it. I bought and retain it for the induction noise. More "performance," at least in the sound area.

-- Chuck

I've had the K&N intake.
Pros - sound. Maybe a slight slight increase in throttle response. Maybe a slight slight increase in power. Neither are really all the noticeable. It is very very easy to clean the filter. Just buy the kit on amazon. Remove the filter (anyone who knows how to use a screw driver can do it), Spray the filter with the cleaner. Use a hose and spray the filter from inside out to get all the dirt out. Let it sit in the sun and dry for a few hours, spray with the oil then re-install. Then you're good for a year.

Cons - heat soak: in the summer the engine bay gets hot. Or if you are sitting in stop and go traffic the engine bay gets hot. Or if you are sitting at a light and engine bay gets hot (you get the idea)... then you go to accelerate or pull away from the light, the engine gulps in a big inhale of heat saturated air and bogs down. I swear I lost power more often than I gained. The stock intake does a great job of only drawing in air from the outside. So - if you don't mind doing it, I'd suggest going back to stock. You can also use a K&N filter in the stock box (which is what I did initially).

I have done rolling studies on the FIPK vs. OEM intake. Consistently, at speed, the FIPK runs 10 degrees cooler than the OEM in nearly all temperatures tested (2006 DBW s2000). In addition, when waiting in the hot summer heat in the autocross lane, the IAT with FIPK gets hot...but within just a few seconds of setting off, the IAT drops significantly. Does this translate to more power? Certainly more BWAAAAAA!

just before I set off at the start line or stop light, I blip the throttle several times, but in the summer heat, the computer will pull timing and you'll bog down regardless. Even worse with the A/C on. Run highest octane fuel you can (94 here in Canada) to help improve resistance to detonation.

darcy