Automobiles Forum banner

W12 information for conversion.

39K views 60 replies 17 participants last post by  Boostedsc 
#1 ·
Hi all, I'm looking using a W12 engine in my next project but finding out technical information on these engines isn't easy!

I know that these are several different versions with the first variation coming out in the Audi A8 D2. As this is the most likely for the conversion due to the rest getting closer to vehicles from 2006 onwards and may be involving can-bus... I'll probably be concentrating on this engine.

I've heard of weaknesses of the crank but don't which engines in particular this affects.

What is the engine to transmission bolt up pattern? The majority of W12s seem to come as autos so I'll be needing a flywheel etc which will work with it and a transmission. I know that the W12 is basically two VR6 engines together but does that mean that they use the VR6 bolt up pattern?

I have an 01E 6 speed kicking around...

Cheers.

MG
 
#52 ·
MikkiJayne said:
Could you get an insert made to fit the Phaeton flex plate? Or is that too big to go in the gearbox?
Too big to fit inside.

I'm pretty much out on a limb here as I can't find anyone who has tuned a W12 engine.

I've no idea as to what flywheel weight is a good idea, how much more power/torque I can get from this with proper tuned length headers, what size exhaust to go for, etc etc.

MG
 
#53 ·
Mickey said:
I have found someone who makes an adaptor plate to go from the W12 to an Audi manual gearbox - he makes the kit for the C5 RS6 and that shares the same bolt pattern as the W12... but... the kit is over $2,000 which I don't have.
Is the guy here in the states by chance? I know of someone that does the conversions for RS6, A6 4.2, A8/S8, etc.
BTW, I love that you are tackling this type of project with THIS powerplant. There are dozens of alternatives and ppl are always going to ask "why use this engine when you could use that one," etc...I like seeing a project that goes outside the lines of what a "normal" swap would be. I heard the same rhetoric way back in 1995 when I decided to build the world's first Scirocco VR6..MikkiJayne could understand I know!
Keep on trucking mate, I will be watching this post.
 
#54 ·
AudiA4_20T said:
Almost positive you can use the SteveKen adapter kit for the trans. The wiring shouldn't be tough, the technology isn't that advanced for an 04ish car. Just use the W12 cluster and wire it up correctly.
It's Steve that I've been in touch with. I sent him detailed photos etc to help check that the W12 has the same bolt pattern. I just can't afford to buy the kit

MG
 
#56 ·
I haven't tried tbh. I'm not that worried about the wiring at present. I know someone who can re-write the ECUs when I need to.

I did however find this photo...



I want these headers!!

I have been in touch with the manufacturer but they want almost £4,000 to make them!

I'll have to keep looking.

MG
 
#59 ·
I've been looking into other gearbox choices and have realised that the R8 6 speed manual gearbox offers a possible bolt up solution.

The question is whether the bolt pattern on the R8 engine is similar enough to the W12 to make it work.

So... here's the ask!

I've grabbed a photo of the R8 BYH engine but I don't have the ability to overlay it onto the W12 engine. Please could someone do this and post it up here?

Here's the photo of the BYH.



MG
 
#60 ·
Thread revival... only 8 years on and no, I haven't finished it. Sorry.

Many things have gotten in the way inc a Divorce and Custody proceedings for my two sons who are now 6 and 4.

Anyway.. back to the W12 info.

I've had an adaptor plate made to bolt the W12 to a Boxster S (986) 6 speed gearbox (same bolt up fitment as a 996 gearbox) but I'm still working on the flywheel.





I have found a couple of possible options for flywheel and clutch that I have found which are factory parts. I don't want to buy a one-off kit.

The issue has been that the W12 6.0 has 408 ftlbs of torque. Very few VAG vehicles (I'm concentrating on parts that will bolt together) have this much torque and are bolted to a manual gearbox.

1) Audi R8 V10 (413ftlbs) flywheel and clutch. This bolts up to the W12 crank and is a dual clutch disc setup.

The issue is making an input shaft adaptor/extension that will slip onto the Boxster S (986) input shaft and into the R8 V10 clutch. I have managed to get my hands on a second hand set and an input shaft from an R8 gearbox (not easy to find) and am now looking to have it modified to fit between the gearbox and engine.
.

2) Audi 3.0TDi V6 (368 ft lbs) flywheel and clutch. Again this bolts up to the W12 crank and has the spacer bell which helps with the 50mm depth of the adaptor plate.
.

MG
 
#61 ·
I am really interested in this project because I am debating on a w12 swap into a C5 Allroad. I used to have a W12 A8L (2009) so I have an understanding to their complexity but I lived that motor. Any updates or further information you could share would be greatly appreciated.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top