whiteflash

Well in a moment of idiocy, I ordered the wrong K&N Filter for my FiPK. For whatever retarded reason I looked up the standard K&N S2000 filter, and not the FiPK. It arrived today and I of course did a major face palm. But then I got to wondering...

The standard S K&N filter is MUCH wider, and probably a good 2"+ longer. It fits the tubing right, but there's about a 1/2" of clearance issue. Then I got to thinking, would a larger filter (especially marginally) draw and/or filter better than the smaller one? Removing a 1/2" off the tubing would be very, very simple.

Has anyone tried this and seen any bad results? Or any thoughts? Otherwise I'll just send it back to Amazon and recollect my pride

starchland

According to kn, you want the smallest filter that still flows your max cfm. According to my research, the stock filter is just about perfect (duh, right), or a little more. They also say that a shorter filter is better. It has to do with airflow. However, adding a velocity stack would probably change all that. The kn stock replacement has an ugly edge on the inside, surely adding turbulence which is not a good thing.

dirtykoala

my only input is this:

i dont know how it will affect performance, probably not noticeably, but when you increase the flow, you decrease the pressure (like having your thumb half way covering a garden hose, vs not covering it at all). if K&N set their intake up with a certain diameter tube, and a certain size filter, they probably did so for a reason, it might be getting a nice mix of flow and pressure.

just a thought, could mean nothing at all.

also though, i guess since you are pulling on the filter from the engine, not pushing, maybe it doesnt matter at all since the flow will ultimately be restricted by the size of the intake piping, and a bigger filter just means cleaning it less?

or

since the filter is restrictive, you have more restrictive surface area to pull against than you do the smaller one that was designed with the intake system, so your engine has to fight more to get air?

just thoughts.

Saki GT

The engine is going to pull in as much air as it needs, all the filter size does is effect the velocity of air through the media. I'd just get the correct size filter and be done with it, but if you want to go through the trouble of resizing the pipe, no harm there.

rrounds

Back in the 70's I raced off road bikes(desert racing) and we would use the biggest that would fit the bike. That way it took longer to plug up and restrict the airflow to the engine. If you put this downstream of the air filter you could see if the filter was flowing enough and when to clean/replace it.

http://www.filterminder.com/hfmw_air.asp

and here is a good read on how the gauge works

http://www.aftermarketsuppliers.org/...lter-Life.html

I use the biggest filter that will fit, it filters better with less restriction on the intake side of your engine. You want the lowest amount of vacuum that you can get on the intake before the throttle body.

ROD

redlineracing

The OEM sized K&N filter is the E-2435.Works just fine on my03S.Had it for 50k+ miles.Cleaned & reoiled at every OCI.

\rlr
carolina

dwight

The amount of air the engine pulls in is not fixed.
http://en.wikipedia.org/wiki/Volumetric_efficiency

SgtB

You want the biggest filter you can fit. The bigger it is the less resistance it has. The filter is always "in the way" so try to minimize it as much as possible.

Saki GT

whiteflash

Right on guys, I knew it wasn't going to be an 'issue' I just wasn't sure if it'd effect the FiPK in a negative way. Since I'm convinced it won't now, I'll go ahead and cut off 1/2" and be done with it. Worst case scenario if I feel anything I don't like, a 1/2" won't effect the sitting or placement of the FiPK filter. Thanks guys!