Hi, well basically i want to put a new turbo on my S3, ive spoken to audi and there are 2 separate part numbers for the K04's, one for the APY engines and one for the BAM ect. The question is: what is the difference between the two? can i fit a the turbo from a BAM to my APY? I asked the audi stealer and they couldnt tell me all they asked is if my car has ESP, which it does. Any advice/help would be much appreciated.