You wont be dissapointed Robert, after having a tweaked one the standard setup with that torque murdering ecu controller just doesnt make sense.
Just seen your post Mathew, yes the noise of a V is lovely
![Cool 8-)](./images/smilies/icon_cool.gif)
A dump valve should always be the re circ type, if not it will dump air out of the inlet the ecu has already allowed fuel for, hence the engine will run really rich after lift off, loosing power and bringing on an eml light as you say. They do not create more power, i fitted mine as i could hear compressor stall during wot gear changes, now the the boost comes on smoothly after gear changes and there are no chavy noises, other than the exhaust.
D