Well there are different turbo units fitted across the range on the 1.9td xantia.
Ones I have seen fitted so far are the Garrett T2 (as on mine), Garrett T15, KKK K03 and not forgetting the KKK K14. All of these turbo's are different in the way they boost and their sizes. The T2 fitted to mine is one of the largest and higher boost capable units fitted as standard.
I want to try out a twin turbo setup, using a TD04L from an imprezza as a secondary charger in parallel at a higher boost. Not sure how that will work out though, also looking into fitting a 92mm crank from a 2.1 and a suitable 6spd box to make it better at cruising speed ... Eventual aim is between 150-200bhp on this engine