[T-sport]

The stock bosche valve is ok, but wont last as long as a forge or other aftermarket valve as they are prone to breaking(due to a cardboard diaphram inside)...

If you plan on any future power upgrade, ie. remap etc you should really think of upgrading from the bosche as it probably wont handle the extra boost through it very long without braking on you and so in the long run you will be forking out again for another Bosche and so on ...