Oxnardo Ring

What model year? Do you know the transmission code?

Audi S8 Rules

2002.. ok I think the code is FBG... Does anyone know what is interchangeable if any? is an A8 transmission the same? maybe just different torque converter? or?

jfrahm

A8 gear ratio is different and there are some wiring differences, I do not think it's realistic to mod it to work in an S8. No idea about the S6.

JAA 4.2

I was under the impression that the S6 and S8 trans are identical. Scott sold it to me knowing I wanted to use it in my S8.

From Tozo:
Pre-facelift A8 has a 2,7:1 final drive ratio. Post-facelift A8 has a 2,9:1 final drive ratio. The S8 has a 3,7:1 final drive ratio. That looks simple, right?
Well, all A8 has a 3,7:1 (37ring/10pinion)rear end and the S8 has a 4,11:1 (37ring/9pinion)rear end. there is a gear set right after the torsen diff. That is where Audi plays with the final drive ratio.

jfrahm

Looks like the final drive ratio is different:

https://www.audiworld.com/model/s6/02/avant.pdf

https://www.audiworld.com/model/s8/02/s8.pdf

JAA 4.2

It is, but the final drive lives in the transmission. So, you either need to swap an A8 front ring/pinion into the trans or an S4/S6/S8 rear diff out back.

Audi S8 Rules

Ok thanks guys... I called a few wreckers... they seem to have the simple software telling them what is interchangeable or not. So this jives with what the wrecker said, no interchangeability... '01-'03 S8's only.