From the depths of my rusty memory, so this will need corroborating, the boost pressure for controlling the the extra fuel when the turbo is spooled up, is a diaphragm on the injector pump.
So if there is no boost, it wont stick the extra fuel in. block the pipe off.
So, running with a filter direct into the air intake manifold, should work, albeit loosing 1/3rd of the performance.
The most effective way of turning petrol into noise without the side-effect of horsepower