Turbo chatter
 

Having got over the initial joy of having a Bailey piston dump valve, I'm really after the chatter that all the rally Impreza's have. I understand that a induction kit is needed and that the dump valve must be removed and the associated pipes blanked off. What performance changes if any can I expect, and are there any reliability issues with the pressurized air going back through the turbo?.

Any help would be much appreciated:norty:

There are any number of threads on this very subject, so a quick click of the Search button will save a lot of repeat typing.

To address your points briefly, you don't need an induction kit to experience this noise. It'll do it with the standard induction tract, but it's a lot louder with an aftermarket inlet due to the removal of the resonator. The dump valve must indeed be removed and the pipes blocked - this is what causes the noise. You may experience an improvement in throttle response under certain conditions, especially on-off-on throttle driving of the type you do lots on the track but very rarely on the road.

There are potential reliability issues, both for the turbo itself and for things like your car's mass airflow sensor, assuming you still have one. It may work fine for years, it may quickly result in a damaged engine, as with any such mod you pays your money and takes your choice. All depends on what hardware you have at the moment, what sort of nick it's in right now, how much boost you run and loads more factors besides. Some turbos can handle it better than others, for example (TD04/05 are more robust than most VF's).

You could always, as mentioned only half jokingly before, get a CD of turbo reversion noises and link your stereo to the throttle position sensor so that it plays a track at random whenever you lift off. All the sound you want without any risk to your engine.

Search is your friend.