What does the AEM air bypass valve do? Does it jut filter out the water? And would i loose any presure?? Would it be good to put on for a cold air intake so i dont get water from snow and water in the winter?? Or should i just not put intake in untill spring??

 

It really only works when your intake is completely submerged in water. Small amounts of water from rain or snow will still make it to the intake manifold, but small droplettes like that are no harm to the engine. I just put on the bypass valve last week for peace of mind. AEM says in some rare situations you may loose power, but I don't think I lost any. Better safe than sorry for sure. The hardest part is cutting and filing the intake pipe.