Exhaust Flapper Vacuum Valve, Stainless Steel – 2.5″ (64mm) Diameter, 90 degree (Vacuum Closes valve)

These Stainless Steel Exhaust Flapper valves are great for getting the best of both worlds when building a custom exhaust system by allowing you to close a portion of the exhaust or one side to force the mufflers to baflle more thus making it quieter. They are best located on mufflers with dual outlets on one of the outlets, so when closed your exhaust will be much quieter. They are open by default and require vacuum to close.  vacuum canister is mounted at a 90 degree angle in relation to exhaust flow and they cane be mounted in any direction of flow.

NOTE: These are designed to be welded into your exhaust system by a trained welder and allow you to bolt on to close the valves by applying vacuum.  This can be done with your own manually controlled vacuum solenoid or reusing the factory system on a car that had a vacuum valve from the factory which applied vacuum to quite the car. Also keep in mind sometimes the open side of the exhaust or muffler when the flap is closed may need some restriction if the system is so large there is not enough back pressure to quiet the car.