Does anyone know where the restrictor is that helps prevent overboost by flattening pressure spikes to the overboost detector?

I've got a 94WRX with a new full ScoobySport exhaust system.

I've heard that the restrictor is a small brass thing, however all I can find is a plastic one in the hose leading from the inlet manifold to the wastegate solenoid.

Does anyone have any ideas?

thanks in advance,

Steve.

Its in the short rubber pipe leading from the compressor out metal-pipe that leads to a T-piece and then to the wastegate and solenoid control.

All on the left of the I/Cooler.....