Hey. I just an AEM Cold Air Intake on my civic, and I was wondering if it's really necessary to get a bypass valve? And what exactly do they mean when they say "...protect your engine in the event that your cold air intake filter ever becomes submerged in water."? Does this literally mean that your filter is underwater? Why would it become submerged in water in the first place unless you are like driving through a lake or something? Im confused.

 

YES BUY IT. You don't have to have your engine that low to get the intake to suck up water. About three to four inches is enough to **** your engine over. Trust me, happened to me in not too much water. Since you're in NC I highly recommend it since you guys get a good amount of rain. If you're ever caught in a downpour a flashflood type of water across a road could cause your intake to suck up water.

 

oh ok so water just gradually get sucked up into your filter when its raining or wet and eventually submerges the whole thing in water. Gotcha. OK i'm off to buy one.

 

no no no, not just gradually when you're driving in the rain. rain driving won't don nothing. but if you come to water on the road that is 3-4 inches deep you could be in trouble. and since you're in an area where it rains a lot the likelyhood of you hitting a spot like this is high i would say.

 

Oh ok i get it now. So i wanna watch out for really big puddles and flash flooding. Just out of curiousity, does a bypass valve hinder performance, because it seems like it would interrupt the airflow or something. Or maybe I just have no clue what i'm talking about.

 

I don't think anyone has dyno'd with and without one to see the actual change. But if there is any change it's minimal and worth it instead of risking your block.

 

k cool. thanks man.

 

Even if it did, the protection from hydrolock is worth losing a few HP/Torque numbers.

 

Too bad it doesn't really help if water gradually gets on the CAI filter. The filter has to be SUBMERGED in water...for it to work...if your gradually driving and water splashes/sprinkles on the filter, some liquid can still get sucked up. But I do admit a bypass valve is worth the purchase and helpful but i don't think it garentuees complete protection from hydrolock.

 

I would hope that small amounts of liquid in the pipe would evaporate before they reach the engine, the CAI piping does get rather hot.