Does anybody have any experience of the HKS sequential dump valve? How much, where from etc etc etc ...

 

There's a few other threads relating to the subject but anyway...
I've had one fitted for over 2 years.

Excellent quality,easy to fit,looks great(if that's important) and very well engineered (as all HKS kit appears to be), but expensive.

It's easily adjustable, and very versatile (can be fitted to standard-tune Impreza but will also happily operate with very high boost pressures due to its sequential design).

You probably know the concept already but it operates as a dual-valve system that is of the pull-type as opposed to push(which most other dump-valves are), which allegedly gives it better sealing.
The small,fast reacting, primary valve operates on its own under normal circumstances and the larger secondary valve operates when additional relief is needed over the primary valve,such as in high-boost applications.

Main HKS dealer is Torque Developments International plc (0181 591 0442), although a few other HKS franchises have recently appeared.

Price is £235+vat (at TDI)

 

Does this dump valve vent back into the air inlet pipework or into free air ?

Bob

 

Bob,
It's non-recirculatory,just venting into free-air. As a result it's also quite noisy.