Just replaced my OEM airfilter with a drop-in K&N E-2435 filter, drove few miles on freeway and local road.

couple things I noticed:

1. Sounds louder, both at low and high rpm
2. Power surge is little faster - feel little more power

If any one of you guys also have a K&N E-2435 filter, any comments?

 

is that the part number for the direct replacement? I plan on doing that along with gutting the air box and eventually a spoon snorkle or if i hit the lotto the J's

 

I added one about 6 months ago. Some say that the larger holes in the filter allow more dirt in, although after 6 months, the intake box and pipe towards the engine aren't really much different from 6 months ago. I don't have pictures to support this, so argue if you'd like, but I think it's acceptable.

My 04 has a better low-end throttle feel - it's easier to start out if you don't want to rev to 4k before you get off the clutch. There is also a noticeable decrease in the time it takes the engine to get to redline once the high-lift cams engage. I saw this on both my '00 Civic Si (B18 engine) and '02 RSX-S (K20), much more pronouced with the RSX. I imagine a cold air would yield marginally better results, but given these filters are $50 and require zero modification, I think it's an essential upgrade.

My Pilot is ready for a new air filter, and I figure it's worth it to add a K&N there as well - why not, right?

 

I think that power gain is from your brain dyno. not your butt dyno A filter swap alone will net you .87763 HP dyno proven

 

You wouldn't see the dirt show up until you do an oil analysis on it. I would say the dirt content is 5-10X more than the stock filter.

More air=more holes=more dirt=less engine life. But hey if a bit more power is your priority then go the K&N route.

 

Anytime you have more air flow, obviously more dirt's going to get in as well, that's just common sense.
However, it isn't like your engine will die in 10k miles. Years ago I had this old Eclipse and we put a cold air intake (one that sits at the bottom of the bumper right in the way of dirt/water/anything on the road) and it came with a K&N filter. For the last two years my dad has used it as a beater for his daily commute. He's put about 40 thousand miles on the car without even cleaning the filter once (because he doesn't care about the car at all) and the engine is still doing fine.
Point being: if the Chrysler engine in the Eclipse can take the dirt from a non-maintained K&N that is picking up 10 times more dirt than the S2000 intake for 40k miles, I highly doubt the K&N in your boxed intake is going to be the death of your S2K's engine.

 

the more dirty the K&N is the better it works but in keeping dirt out, essentially the holes get plugged but then you lose the advantage that you were looking for in the first place.

I would think the Eclipse had looser tolerances in the engine than the F20C. Hmm spinning to 9k, i rather not have higher level of dirt in there, thanks.

If anyone wants to see some oil analysis results, just go bobistheoilguy.com and do search for K&N and oil analysis.

Not to be dumping on the K&N parade but just want to point out the trade offs.

 

I had the drop in filter, but stopped using it when I saw tests that were done showing how crappy it really filters. And you're not going to see any increase in power.

I am using the good ol' OEM paper filter.

 

Is this the same filter they use on the FPIK intake?