The charger isn't spooling, and the electronic bypass valve stays open.

Now if i manually close the valve, air is forced through the charger turning the clutched charger pulley.

When i rev the engine with the bypass left open, the pulley doesn't engage the clutch. well it seems to catch now and again but that's it.

I've ordered a "new" bypass valve for £28... but after thinking about it, it's probably the electronic clutched pulley causing the issue?

I've searched for a new one, but can only find some on the usa ebay for 600 and something $.
Am i right in thinking their is an aftermarket performance item?
Where do you suggest getting the normal clutch pulley, and where do you suggest getting an aftermarket performance item.

Jack