Audi A4 B5 1.9 81kw AFN 1996 AvantYou have few options, best to tell us what car is the AFN bolted to ! Bv43a/b or gtb1749vl or even a gtb1756vk or any hybrid will flow better than stock turbo. Folk swear by the new gtd/gtc series...good midrange and plenty torque low down makes very good
daily driver !
Also look at the list skaude compiled with all turbos suitable for 1.9 tdi from stock all the way to 500 Bhp ! Look turbodatabase...