Inline style blow off valves?
https://www.ebay.com/itm/OBX-Univers...oAAOxy1RZSYvp8
Description
OBX Inline Blow Off valves are designed to work with all 2.5" outer diameter inlet and outlet piping systems. The valve system is installed using a slip fit design and sealed via inner o-ring to seal charged air after an intercooler. This pipe is perforated with a ring of ports which are alternately covered or uncovered by means of a ring shaped piston which wraps around the pipe and is actuated by vacuum and boost pressure to open as soon as the throttle is closed.Note: This space saving design inline blow off valve is designed to stay open at idle and is not recommended for vehicles equipped with Mass Air Flow sensors unless the application is running a blow through setup.
Certainly a lot neater and more compact than conventional designs, and perhaps also a stronger seal on boost ? Not that that is much of a concern in most cases anyway.






