when the filter starts sucking up too much water or actually when the vacuum gets to high the valve opens and allows air to get to the intake, this happens when the filter gets submerged, it helps in memphis with all the rain, and no the AEM doesn't come with one
i would recomend one if you do not have it yet...especially if it rains where you stay at...i already hydrolocked my engine once and it is not cheap...and i wasnt in a pond or lake or even 2 feet of water...i was just driving on the interstate and that was that...so just get one it doesnt hurt. better safe than sorry.
What is water suck?
Spend some time on the Honda-performance mailing list, or on any number of the Honda specific web boards, and you'll hear someone saying how they just got a new intake and now they are pathologically afraid of getting any water in their engine. They suddenly seem afraid to venture out in the rain.
What is water suck? Simply put, it is an occurance wherin a large amount of water gets introduced into a running engine. Being a liquid, and thus incompressible, the water fills the cylinders and abruptly stops the engine's rotation, causing a large amount of stress to the pistons, connecting rods, and crankshaft. Usually this stress is very high, causing terminal damage, and the engine has to be disassembled and parts replaced. Needless to say, this is bad and should be avoided.
So all water in the intake is bad?
Nope. only when there is sufficient water introduced to a piston to prevent the motor from fully travelling the compression stroke will this be a problem. In fact, water in the intake can actually be a good thing. Many ... bla, bla, bla, no time to finish now...
While not impossible, water suck is not very likely as long as you drive with your brain engaged. I have yet to hear a story involving engine damage done to a car by water that wasn't due to the driver being unnecessarily careless. The amount of fear regarding water suck is absolutely disproportionate to the actual danger as long as you think while you drive. If, even after reading this, you still feel uneasy about sucking water into your engine, don't get an intake which makes you nervous! We're not talking about a 40hp difference, so if it makes you feel less worried, then just leave it off!
Don't buy something if you're going to live in fear everytime the skies cloud over.
If you get an intake and put a bypass valve in it, you lose about 3/4 of the performance that you gained by putting the intake on in the first place. I hardly think that it is worth 250 dollars (rougly) for 2 or so WHP.
I guess this is kinda still off the subject, but Justin, do you have any proof that you lose that hp, like some charts or something. I'm not trying to be a prick or anything, just wanna know. I was going to get a CAI but was going to put a bypass on it just for a piece of mind. I would buy it even if it made me nervous for the hp gain, and sound (I know that alone is a good reason to buy a mod but its true) plus its relatively cheep and I'm relatively poor, so it works out.But hydrolocking does occur, so if I get a CAI I will get a bypass valve. However if you do lose all this HP, I'll just get a short ram. So please get back to me on this one, I am really courious. Thanks.
Get the short ram if you want to use the bypass valve. I have no charts, no, but a lot of very intellectual people from this site will back me up on the fact that the bypass valve takes away some of the gains you'll see out of the intake.