I am building my RS6 right now and we are...(making up numbers here)...shooting for maybe 750-850. I will guarantee you it will be way over 20k in parts lswing.
I don't have the exact cost of each part in front of me but I will list parts we are using.
Custom hybrid turbos....over 5k.
S8 European 4.2 TT rebuilt block...no adapter kit needed. You have to install steel sleeves.
Pauter Rods
J&E pistons 8.5CR
Ferrera Valves
Custom ported heads
Custom valve springs
Maybe camshafts..
Wagner intercoolers
Custom high flow headers in stock configuration
Obviously custom exhaust
01E TDI built
Twin disc to hold 800-1000ftlbs. Over 3K.
I am doing a custom gear set but that is just icing...
Upgraded diff front and rear. Not needed..
Aquamist 100% methanol injection
034 Surge Tank w/ Bosch 044
Bosch 044 intank
Custom fuel injectors
Vented hood
Custom tune and dyno time.
Custom intake and MAFs.
You have to get the intake flowing way more and the exhaust flowing way more.
I am not doing the labor. This is R8 kind of money.....and not a older stock one either. Well, that would include all the extras such as wheels, suspension, mounts and a host of other none essentials. After all of this the car might be able to be sold for 45k maybe. This is totally an irrational, emotional car build. I wouldn't recommend this for the faint of heart....or billfold.
I still am not sure were we end up HP wise. There is a build going on in Germany right now that is shooting for over 900hp and his build is very expensive. He is using stock location for turbos but not stock exhaust manifolds. I decided to not go with the BW EFR 7163 because I didn't want to deal with the custom exhaust manifold headaches....and to just get this thing moving along.
It would be cool to put together a kit but AMD and EPL basically do that....if you can actually get someone to talk to you more than once every 2.5 months. I gave up on that crap....but I digress. They are not getting into the 800-1000hp range though. Not that they couldn't but to go that far you are on another level of cost.
I would say build yourself and car and dial it in and then think about a kit. You might be putting the cart before the horse with serious talk about a kit. A collection of unproven parts does not make a kit. Hope I don't sound like a dick..
I had a 517 built transmission with everything they could throw at it. I was making about 571ftlbs and I felt very disconnected from my power. It was ok but not what I am looking for. I should have done the manual in the first place.
By the way, anyone know what ever happened to Milka's build??