Specifications:
Made from stainless steel 304.
Valve flap diameter 85mm approx..
Pipe flange inner diameter 89mm.
Actuator begins to open at 2.5psi of positive pressure.
Suited for turbo applications.

The opening and closing of the valve flap is controlled by a vacuum source which also has positive pressure under boost, it works on the same concept as your turbo wastegate. A vacuum line will need to be connected from your inlet manifold down to the bypass valve.

The bypass valve should not be used inline on your exhaust and should be welded on a Y piece pipe to bypass the exhaust when open. 

A Boost T or boost controller can be used to help delay the opening of the valve and keep it closed longer.

Note: The bypass valve system should be installed by a qualified person/workshop who has experience, we do not accept refunds or returns simply because you are not capable of installing the product.