Building a Unicorn - V6 and manual swapping an A4 Avant How-to/DIY

[jkrew]

First off, I know there have been a few build threads and I really appreciate all of the detail that has gone into those. I have a few questions leading up to this project and I'd like to make this thread as detailed as possible for those that may want to take this on themselves.

I own a 2011 Prestige Avant. I'd like to make it faster and add an extra pedal. My main goal is to get into the 150 club at Bonneville next summer and then eventually try to go for a landspeed record in a wagon the following year after an engine rebuild. I'm turning 50 in a few years and I figured this was better than an expensive 911 or a cheap affair.

What I'd like help with is all of the things that one can do to make this easier in the up-front.

I've heard from a few folks that have done the swap that finding an S4 of the same year and same build level would help with the control modules but was wondering if this really matters. And if not, could one potentially purchase an 8.5 so you could take advantage of all of the facelift and PI that went into the updated models?

I just discovered the Copart app. Are there other donor car-buying options?
Are there big things to look out for in terms of fitment? Electrical nightmares? Things needing to be fabricated?
Are there any shops that are particularly good/experienced at this swap? Any users who have done this themselves that I can add to a list?
What are the incidentals that need to be considered such as new exhaust, rear diff stuff, possible change of bolt/mounting locations between the B8 and 8.5? Sport diff vs. ???

I really appreciate the knowledge and apologize for making a thread that's kind of been made before. Hopefully this one will be able to keep all of the knowledge in one place.

[A4B8 2.0tfsi]

Is an S4 a unicorn? Rolling thousands of them, with manual from factory. 09-11. Just import one and be done with it.

[Matt Devo]

Is an S4 a unicorn? Rolling thousands of them, with manual from factory. 09-11. Just import one and be done with it.

you clearly are unaware of how difficult and expensive that is to do in the USA for vehicles under 25 years old.

Sent from my Pixel 8 using Tapatalk

[shreddykrueger]

Source the same model year s4 for the donor, that’ll make the swap much easier. Quite a few have done b8.5, just going to require a little more work. You’ll want a full car because you never know exactly what all parts you might need to use.

Pretty keen with wiring diagrams? That’ll help to retain factory functionality as well as access to program/code everything.

You’ll want to do all the maintenance items while the engine is out as well.

Here’s my build, feel free to reach out if you have any questions.

good luck!

https://www.audizine.com/forum/showt...S4-Avant-Build