I know AEM cold air intakes are the best. My question is with the bypass valve. I hear they hurt the performance of the intake. Does it? If so how?

 

it really depends on where you live and what type of weather. if you live where it rains a lot then you might want to consider having the bypass valve for safety purposes. in my opinion, the only way you're going to suck up water is if you go into a deep puddle then your filter gets submerged, then you floor it. take it easy on the throttle for awhile until the water is out of the filter and your engine will be safe.