AEM Bypass Valves - AEM Intakes
According to this dealer, it is a bypass valve that only protects you in the case that the pressure drops in the CAI tube -- as a result of water at the filter. Read their paragraph - very helpful.
As I understand it (correct me if I'm off), this would only activate when significant levels of water (immersion in a puddle, or a snow-clogged filter) were present, not just for drops running up the tube. As water requires more suction to lift it the length of the tube, a vacuum situation would be created, the pressure would drop, and the orange plastic in the bypass would open, allowing the engine to draw air through the foam. This prevents the pressure from building up enough to draw the water up the tube.
Make sense? that's my quick take on it- I guess my question is, this sounds like a protection for a major event, as in, driving through standing water, or a totally soaked filter. How much protection does this really afford for less-catastrophic water levels that won't necessarily make big changes to the pressure in the intake? Probably none.