AEM® 20-400S - 2.25" Air Bypass Valve

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AEM® - Air Bypass ValveAEM® - Air Bypass ValveAEM® - Air Bypass Valve Installation InstructionAEM Authorized DealerAEM Special OffersAEM Special Offers
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Universal Fit
Fitment Notes:
  • Will Not Fit Supercharged Models.
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Universal 2.25" Air Bypass Valve (20-400S) by AEM®. AEM's patented air bypass valve is cheap insurance for your engine. Should the air filter become submerged, the air bypass valve automatically takes over, shutting off induction from the filter and instead drawing air through the valve’s external diaphragm.

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  • Virtually eliminates the chance of the intake system ingesting water if the air filter becomes submerged
  • Installs along the upper portion of the air intake pipe
  • Includes complete hardware and installation instructions

Whether you cross over water when four-wheeling off-road or you drive in an area where the roads are frequently flooded, you should think about the possibility of the air filter on your cold air intake system becoming submerged in water. If your engine ingests water you could have catastrophic and expensive engine damage! The patented AEM Air Bypass Valve is cheap insurance against such an occurrence. The bypass valve installs on the upper portion of the intake pipe. If the air filter becomes submerged, the valve closes off induction at the filter, rerouting air through its external diaphragm to keep water out and air flowing in. The Air Bypass Valve comes with complete instructions and all necessary mounting hardware.

John Concialdi and Bob Sullivan co founded AEM in 1987 as a tuning performance shop in Compton California. Both men had extensive technical backgrounds in engines and engine airflow, and in a short time AEM became the go-to company for performance modifications. By 1993, when the company relocated to Gardena California, it had become commonplace to see cars wearing the bright yellow AEM logo winning races. AEM tirelessly dyno tested and worked closely with racers and auto manufacturers in an effort to understand intake energy dynamics. This resulted in the sale of their first air intake kit in 1994. AEM can boast a number of firsts and unique products: They’re the first manufacturer to make an intake system with specific tube lengths and diameters to take advantage of pressure waves in the inlet tract; they developed the first dual chamber intake kit; they designed an air bypass valve to prevent hydro-lock should the air filter ingest water; and they created one of the first hybrid intake systems for modified cars. AEM continues to create innovative products to help you get more power from your car.

Part Number:

Vehicle Fitment

This part is universal
Year Make Model Fitment Notes:
ALL       ALL        ALL         This part is universal
  • Will Not Fit Supercharged Models.
AEM® - Air Bypass ValveAEM® 20-400S - 2.25" Air Bypass Valve    $53.99
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