K&N Air Filter

[TristanGS]

I'm strapped for cash, too.  That's why I'm telling you not to blow greenbacks on an air filter.  I did, and I wish I hadn't.  Now, I find myself putting my knee down when I'm not paying attention, with nothing but denim between my patella and asphalt. 

Like I said, we're not trying to dog you or anything.  I wish I had my Dad's jacket.  You're wearing more than some idiots, so I guess that's something.  But, invest in yourself before your bike.  Please. 
Besides, you think you're the first person trying to go as fast as possible?  Why not stand out from the crowd a little? 

Get a spine protector and have I love YOU sew it in, to update that vintage leather.  Or, buy some better gloves.  Or some padded shorts.  They're about the same price.  You'll get a little bit of insurance for your pelvis and lower vertabrae, and it's more comfortable on long rides.  Won't go "whoosh" (unless you fart), you won't get an extra negligible horsepower, and the chicks won't see it (maybe).  I don't think that would matter if you got T-boned in traffic. 

The old leathers are only for the track. My road gear is a good joe rocket ventalated jacket (back protection and all) AGV boots, joe rocket riding pants (knee protection etc.) and tourmaster gloves. I got good street gear, my track gear is lacking though but I have only been once. I plan on getting a back protector before going back. But right now for how rarely I can afford to go to the track I dont want to invest much money into good gear.

[philward]

I have the lunchbox and rejet done on my 05 and from my experience I will have to disagree with some of what has been said here in this thread. There is a noticeable difference to the way the bike rides - besides just sounds, etc.  Although there is a measurable increase in hp, the thing that I think makes more of a difference to me  is how that performance is delivered.  I find with the upgrade my bike's power rolls on smother, quicker and from lower down.  I also like the way it starts up better from cold.

And from a non-performance standpoint I also like the amount of room that getting rid of the stock box has created - I use it to store my wet weather trousers rolled in a length of tube, accessible from the gap in the rightside frame. 

[galahs]

I don't disagree, it's better, just don't expect it to turn the GS in to a rip-snorting rocket

[ke7syv]

A lot of people use the lunchbox and other KN filters as we all know but I've talked to a couple friends who I consider very knowledgeable. When I brought up the idea of switching out the stock air filter for a KN they both mentioned disliked using them because of the pore size. The KN filters allow more air low by decreasing the filtering efficiency. True the size of particles making it through are very tiny and YES there's the oil to aid in filtering but is is fair to say that they improve flow by filtering less? I've thought about getting a KN and adding some more cotton. I know the medical grade stuff was available in something like 5"x10" pads. Not sure how thick but i should be able to split it. Any opinions 

[Bluesmudge]

This is exactly why I have decided not to get a K&N filter to go with my exhaust. Sure you lose a little performance with the stock filter, but you also get better gas milage and longer engine life.
My Dad's DR650 died an early death because of its K&N filter. They just don't filter as well as stock. Is that little performance boost worth shaving thousands of miles off the engine life?

[Weston]

So you think a paper filter is going to filter better than a cloth one with oil? Unless you can prove this, I'm calling BS. Sounds too much like speculation to me.

[5thAve]

Paper filters are generally smaller pore size than cloth, so yeah, technically they filter smaller particles. Also, Cloth+oil filters are easy to put in too much oil, which really plays havoc on fuel-injected systems (hot-wire mass air flow sensors go screwy with oil residue) so a big mistake many people make is putting on too much oil, then getting bad results.  Nothing wrong with a paper filter, in my opinion.

1000's of miles off the engine's life?  Really depends what kinds of conditions you ride in, I guess. Less crap in the air = less need for perfect filtration.

[Bluesmudge]

You can't let more air through and expect the same amount of filtration, that just doesn't make sense.
See here for a comparison between many air filters. You can see that the K&N is one of the worst for actual filtration (Uni seems to be worse), and one of the best for air flow.

http://www.duramax-diesel.com/spicer/index.htm

Compared to the AC, the K&N  "plugged up" nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons.

Even if K&N is correct and theirs filter 99% as well as stock, I don't want 1% more dirt entering my engine constantly, so I'm sticking with paper.

[ke7syv]

You can't let more air through and expect the same amount of filtration, that just doesn't make sense.

Less filtration isn't always the cause for improved air flow. It could be an increase in surface area but it appears KN took the easy route for improving flow. So what do you think about adding some more cotton pad?

[Weston]

Meh. Thanks for providing evidence. BS call officially removed. I still don't think its going to hurt your engine, and I am deffinitely still keeping mine, but i see where your coming from.

[TristanGS]

i wouldnt expect thousands of miles to be lost by it.

[fred]

You can't let more air through and expect the same amount of filtration, that just doesn't make sense.

Less filtration isn't always the cause for improved air flow. It could be an increase in surface area but it appears KN took the easy route for improving flow. So what do you think about adding some more cotton pad?

I don't know about adding cotton pads. I have this terrible vision of them getting sucked in to the carbs and causing all kinds of trouble. It doesn't seem like there'd be any way to attach them so you could be sure they wouldn't come off, especially since they're so flimsy....

As for shaving thousands of miles off the engine life, I'm not so sure. How many GSs out there are even within 10000 miles of the engine life? How about 20000 miles? It seems like the major killer of GS engines is not old age. Most of the posts about dead engines seem to be maintenance related: people run them out of oil, they lean them out until they melt, they float valves, they crash them in to things, but hardly ever seem to ride them until they fall apart or wear so much they cease to function. It makes me wonder how many miles the average GS engine has on it...

[wladziu]

Tristan, you're covered in more gear than I am at the moment, so what can I say? 
If you haven't bought one by now, then enjoy your new filter when you do.

Nice tip on the WW pants, Phil.