AEM air bypass valve, the perfect solution to cut the chances of your AEM cold air intake sucking up water to your engine. The AEM bypass valve is design to trap and hold the water and prevent it from going into your engine to do extensive damage. This is the perfect investment for your engine.

AEM’s air bypass valve for cold air intake systems totally eliminates the unlikely chance of water ingestion, should the filter element become wet from deep puddles, rain, hail, sleet, or snow – or any other water submergence. The valve installs along the upper portion of the inlet pipe on the same axis as the throttle body centerline. Should a drop in pressure occur within the pipe, the valve shuts down induction at the filter and routes incoming air through the valve’s external orifices, eliminating any chance of water ingestion. Crafted from mineral-reinforced nylon so it will never corrodes. AEM does not recommend the use of the bypass valve on engines equipped with forced induction (turbo or superchargers). Additionally, placing nitrous oxide before the bypass valve is dangerous due to fuel contamination of the foam spring/filter as well as degradation of the integrity of the plastic due to the extremely cold temperature of the nitrous oxide. Nitrous oxide can be used downstream of the bypass valve.

The AEM bypass valve is used to protect the engine from hydro locking. Hydro locking occurs when the end of the inlet pipe is submerged in water and the water is sucked into the engine. Driving the vehicle in rainy conditions is not enough to cause a problem unless the vehicle becomes submerged enough that the inlet end of the pipe is immersed in water. Rain impingement on the filter will not cause a hydro-lock condition. The distance of the filter from the road dictates the level of water that can cause damage. This distance varies with the vehicle ride height, which is why there are no published numbers for this measurement. All AEM cold air intakes are to be used with the splash shield that is originally installed on the vehicle for protection and performance. The removal of splash shields deteriorates performance by allowing hot pavement air in the vicinity of the filter and negates any positive pressure created in the air filter area when the vehicle is in motion.

The bypass valve may cause a slight loss in power due to the interrupted wall section created by the internal shape of the valve. In dyno testing we have found that the power loss is minimal. The bypass valve offers great security against hydro locking the engine in rainy conditions. If maximum power is the requirement, we suggest that the bypass valve be used in the rainy season, and when racing use a coupler hose to make a smooth section where the bypass valve goes.