2.75" AEM Bypass Valve (20-402s)AEM
's Air Bypass valve for Cold Air Induction Systems virtually eliminates the unlikely chance of water ingestion should the filter element become wet from deep puddles, rain, hail, sleet or snow-or any other scenario in which the filter element could encounter or become submerged in water. 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 due to filter submersion, the valve shuts down induction at the filter and routes incoming air through its external orifices, eliminating any chance of water ingestion.
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.
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.AEM
's Air Bypass Valve is for use on AEM
2nd Gen Cold Air Systems only and cannot work with 1st Gen AEM Intake
because of the way the 1st Gen is bent/setup.AEM
1st Gen Cold Air Intake
...Installation for AEM Bypass Valve on AEM 2nd Gen Cold Air Intake
The install is pretty simple.
Don't use a hacksaw to cut the pipe, Take it to a nearby muffler shop and asked them to cut it w/ a power tool, takes only 2 secs for them to split the pipe (and is usually done for no charge).
You want to make sure that you cut out the piece marked by the paper template that comes with the bypass valve, otherwise the pipe will not fit correctly.
Install very simple and probably the best thing you can do to protect your engine from water ingestion. (Injen
splash guard can also be purchased to go around your filter for much more protection)