mark kibort

you guys are confusing turbulence and efficiency reduction of an inlet with restriction and pressure drop across the filter. a screen on front of the MAF will cause turbulence and not allow for an efficient flow through it. However, if that same screen was backed off an inch or two, there would be none of the turbulence that would cause flow disruption. the filter material determines the flow restriction. foam flows more than paper and just a plain screen would cause little or no restriction or turbulence. But, on the edge of the maf, it would.

a harrier Jump jet was originally fitted with screens to keep guys on the ground from being sucked in the engine. the jet couldnt even take off. however, if the screens were a few feet a way, this would not be the issue, however that would not be possible. one of the things that the KN actually does, is straighten the flow to the MAF, which is good. Paper does this too, but at a cost of added restriction in the form of a pressure drop accross it. there are a ton of tests done on a flow bench that prove that the pressure drop accross the foam or cotton filter, with screen (to hold it together) is much more free flow than a paper filter. I would guess if we did enough dyno runs, there is a minimal gain, but a gain none the less with KN. (at a cost of less filtration)

however, if you dont seal the air box, under WOT, you are getting unfiltered air anyway.

mk

heinrich

No doubt We are.

Mongo

Eh, I've seen what those screens trap (leaves, a grasshopper - don't ask) and there is no way in my life I would ever 'de-screen' my Mass Air Flow Sensor.

mark kibort

that can be fixed by sealing the airbox and is proof to my point about the leaks. trust me, grass hoppers cant get through the cotton or paper filters

i just did a race up a mountain road this weekend and was racing around with the superbikes. scarry fun. i came back and pulled the filter to shake it out, and there pine needles and a couple of 2" sticks. (in the filter) i wasnt following anyone either. I usually pick up a pile of sand while at laguna seca too! but nothing enters the engine, as the filter is sealed. there is a greater pressure drop across it. ( i know because i measured it with a sensitive pressure gauge by Sunx) about .25 to .3 psi greater drop with the sealed box vs stock straps and no seal. this is actually a reduction in hp by about 1-2%

I seal the air box, by laying a bead of silicon over the filter on both sides where it will touch the cover and base. just before its dry (just tacky) i assemble the airbox and clamp it down creating a near air tight seal between air box and filter. a side benifit is that the cover is not slightly higher so the tension of the straps has greater pressure on the seal too.

mk

SharkSkin

Seems appropriate, this K&N thing always ends up being a religious discussion...