just found this
Originally Posted by Joel@APR View Post
A few things to consider before buying a S3 turbo for your A4:
1.) The turbo exhaust flange on a S3 and A4 are completely different. So, your A4 downpipe will NOT bolt up to this turbo and a custom downpipe will have to be made that incorporates a S3 (or GTI) flange.
2.) The manifold will not seat properly to the head unless the appropriate ear of the exhaust flange is trimmed and a new hole drilled (it will hit the motor mount).
3.) The compressor outlet and inlet of the turbo are in different locations than an A4. You would need custom hoses to make this work.
4.) A4s have a DV that's incorporated into the turbo where as the S3 has no provisions for this. So, your custom compressor outlet hose will also have to have a bung for a DV.
5.) With all of this custom hardware you will also need hose clamps and a custom exhaust gasket.
034 may have provisions for all of this. I just wanted to ensure that no one was mislead into believing you could simply bolt a S3 turbo on your A4, hook up the exhaust and plumbing, and go.
My Solutions;
1) De-cat pipe with the K04 flange for the A4 are available
2) Not scared of a bit of griding and drilling
3) Shouldn't be too difficult
4) Im hoping I can do the same as would be done with the vRS