ljackski

If this is as far reaching as I think it is, we all got the shaft (input)

TheBrit

until you realise the tuners must have it easy, just pull the stock ECU code's torque limits off and bingo! No wonder they're all so keen.

This gearbox thing could be a real dampener. In a way, I hope if there's a problem, enough people have it and get expensive replacement gearboxes under warranty that Audi decide to take the hit on re-engineering them to be a bit stronger. The gearbox is the biggest reason I have for planning on getting rid well before warranty expiry.

I've said it before, but the A8's gearbox (6 HP 32 A I think) would be perfect with this engine, and it supports the V8 diesel with it's monster torque, so it would handle the 4.2T I'd hope. I don't think it would fit though.

ljackski

When I used to delve heavily into the tuning on my 5cyl Audis, there were maybe two reliable chip guys in the U.S.(1995)and there were thousands 200TQ's and UrS4's on the market. I put a post up for this car and all sorts came out of the ether. Software has made the difference. The guy who did mine, Ned Ritchie, was actually an engineer who had to figure all of these things out manually and actually know the physical make up of the ECU circuits.

jimmy94507

Where ae you located? Doesn't sound good if the 04 S4's are having problems. Has A0A technicians been called in on these cases, or are the local dealership technicians left diagnosing the problems? Please keep us posted on their analysis.

Regards, Jim

oatzel

there's a TSB out on the s4. it's the manual tranny that seems to be failing though.

ICONCLS

So we have this amazing Cossie engine and a kludge of a tranny...nice.

TXurS6

Anything built before Oct 7 has a potential problem.<ul><li><a href="https://forums.audiworld.com/s4b6/msgs/45801.phtml">https://forums.audiworld.com/s4b6/msgs/45801.phtml</a</li></ul>

TheBrit

Don't get me wrong - I think the RS 6 is a fantastic car, but it would appear that the gearbox is the weakest part of the overall package.

Rumour is that Cosworth had the RS 6 engine tested to 1000hp+ at the crank on the bench, proving the strength of their block casting.

This <a href="http://www.sovereign-publications.com/auto-art-2.htm">link</a> must be quite old, but it does have some interesting tables of data, and also mentions that testing assumes full-load running isn't possible for prolongued periods. Take another look at the torque curve of even a stock RS 6 and tell me that gearbox peak torque limits can't be broached a significant proportion of the time.

Now the 5 HP 30 gearbox, that would have been more than able to routinely handle the peak torque of the RS 6, but it's not an AWD box. The new 6 HP 26 A and 6 HP 32 A would also handle the torque, but I don't know if the difference between "font allrad" and "heck allrad" would mean a physical fit issue. Also, I assume these boxes will be larger (they are heavier) and physical space in the RS 6 is at a premium anyway (check the width of the trans tunnel compared to any other A6).

ICONCLS

In homage to this thread, I've added a new line to my sig. ;-)

TheBrit

:-)