hope these pics help on how to remove the recirc part of the dump valve
1. locate the rubber recirculation pipe connecting the dump valve to the air box intake.
2. Remove the Plastic pipe that draws fresh air from the out side of the car.( goes Over the top of the engine). this simply pulls towards the engine from the front and is interference fit onto the air filter housing.
3.pull and twist out the pipe from the air box pipe that is connected to the dump valve( Note picture )
4. Unscrew the clamp that is holding the pipe onto the dump valve. this will then allow the pipe to pull off
5. remove pipe and keep hold of for save keeping. you may also want to block the whole left from the pipe to make sure no dust can get sucked in the engine.
6. hey presto !!!!!. you have successfully got rid of the dreaded honking sound and u will now find that u get the "pssssssst" from the dump valve that is favored by many lol.
this is short vid of my mk3 with the above done to it. its not the best vid ever but i will be taking more when i can
http://uk.youtube.com/watch?v=JPjVsjGCckw