Rob your right about the water thing. Here's what I thought about it. Manufactors are worried about people washing bikes at a car washs and spraying water in the intakes. The other is the reason I kept the stock airbox. The airbox internal baffeling and drains should seperate the water and not let it up into the motor. And last, how fast would you need to be going in the rain and how hard would it need to be raining for the wet K&N filter to obstruct air flow to a noticable extent?
The configuration of the ram air intake runners is intended to direct the bulk air flow to an eddy chamber with very complex baffling intended to knock water out without sacrificing intake velocity excessively -- I know this because I saw a wrecked Kaw 636 at a salvage with the left side of the fairing gone and the ram air duct torn open. I immediately recognized the internal configuration as very similar to the dry sump oil tank air / oil separator in a WWII Messerschmidt ME 109, designed for high velocity operation. If it was intended for quiescent drop out there would be minimal baffling.
I also learned from a co worker's Mazda RX-7 which had a NACA duct ram scoop plumbed directly to the air filter housing that it doesn't take a very heavy rain storm to soak an air filter element to the point of losing power: at first the motor ran better, but as the rain got a little heavier (wipers still on slow) the air filter got soaked to the point of producing barely enough power to go up a slight incline. We speculated that surface tension of the water decreased the effective pore size to about 1/3 when dry (based on MAF readings for given throttle position and rpm).
And your right this is just a first attempt to see if the gains are worth the effort. I think they are. I was going to dyno the bike (I have an automotive chassis dyno with a fixtue to hold bikes on it) with and without the scoup. I just need to be able to vary air velocity with wheel speed so the fuel mixture won't go crazy lean at low rpms. Any ideas?
Things get a bit complicated here. First, you will need some method of measuring air velocity, the simplest being an anemometer (wind speed measuring device): I looked on EBAY and found several -- http://cgi.ebay.com/sper-scientific-...QQcmdZViewItem
Is one, but there were quite a few others. With that mounted just above the intake horn you should get a pretty accurate idea of air velocity across it. The biggest problem is getting enough velocity from a fan -- a high speed squirrel cage fan with a 6" outlet rated at 1200 CFM produces an outlet velocity equivalent to 18 mph. I'm afraid in order to reproduce 60 mph wind the fan would have to be rated at 4,700 CFM out of a 6" outlet, and those are very
expensive! At least with the anemometer you would be able to test various fans to see how close to what you need they can produce. Remember as well the you can't just duct the fan output directly to the snorkel -- it must emulate free air flowing past the various bits it will encounter before it gets to the intake to duplicate heat flow, eddying, the effects of a spinning front wheel on flow paths, and the myriad other variables involved in this setup. No mean feat. Of course, you could run it in a wind tunnel equipped with a dyno, but if you think dyno time is expensive ...
Unfortunatley if you want valid results it's going to take some creativity and a fair amount of cash to get them, unless you can locate a dyno facility equipped for this sort of test.