[Biturbos4] Replacement turbos

[Robin Gibson]

Hi guys

Over the last few months I've noticed a slow deterioration in performance and an increase in noise from one of the turbos - it sounds like it is slow to spool up relative to the other one.  No smoke or anything yet, but I reckon I'll have to replace the turbos sooner or later.  I have been to the local Audi dealer but unless I go in with the busted turbos in a carrier bag, he seems unable to figure out the problem.  Can anyone please help me with the following;
  a.. If I buy the VAG COM, will it help me to confirm or identify the problem?  
  b.. If I need to need to replace the turbos (again!) at my own expense, I am tempted to install K04's.  My S4 already has an ABT chip fitted (310 bhp); is the K04 a straight replacement or do I have to have the ECU upgraded also?  There is a company called AmD is England which claims 400 bhp from a Stage 2 upgrade using "RS4" turbos plus ECU mods.  The basic cost is £4,750 which is probably not much more than my local dealer would charge for replacement K03's. I'd rather not have to spend this sort of money but if I have to, is this a better way to go?  
  c.. Am I crazy to consider upgrading an engine with 43k miles on the clock?
I'd appreciate any advice you can offer.  Thanks


Robin Gibson

e-mail: robingibson at cowanlinn.co.uk