Manual 60/40 quattro vs. Tiptronic 50/50 quattro -- differences..?

[Emm]

I'm in the market for an S4 Avant '06 Tiptronic (I want the auto since this will be a daily driven family car; for fun I also have a manual 996 4S '04 :-), but I understand the gearing ratios on the Tip are different from the manual -- plus the preset torque split is 50/50 rather than 60/40. Does anyone here have any idea how this translates into differences in behaviour? Is it practically transparent to the average driver so that you basically need a race track to sense the difference, or will the Tip understeer so much harder that this difference is obvious even during inspired street driving?


I've been a die-hard BMW enthusiast for years, and on my last two BMWs (a Z3 M Coupé '02 and an X5 4.4iA '04) I chose the Kelleners sport exhausts (manufactured by Eisenmann), but I have no idea which exhaust manufacturer is the generally preferred in Audi circles (complete newbie to Audi...). Since I'm in Sweden, I thought I would get a European system -- is there anyone here that can make any recommendations? I know that both MTM and Abt are renowned tuners for Audi, but do they offer nice exhausts for the S4 Avant? Are there others I should look at? What appr. hp gains and weight reduction should one expect? Thanks in advance for friendly advice!

[gIzzE]

I would look at Milltek exhausts as well. They do a complete system, or just the car back. You can go with resonated or non resonated, personally the resonated sounds better, with this it sounds like a nice V8 rumble, with teh non resonated it sounds like an after market exhaust if that makes sense.
Expect about 15bhp gains from the cat back system (approx. €1000) and another 15bhp from the free flow downpipes (approx. €1800).
If you remap as well you can expect 12bhp on its own or 20bhp if done with the exhaust, full system or cat backs.

Regarding the 40/60 split, I don't think there is a 40/60 split with any car other than the RS4, I was talking to Audi at Geneva about this and they were adamant that only the RS4 had the rear bias, all A4's and S4's were still 50:50.
I asked again at my dealer when I started looking for an S4 a few weeks ago as I have also come from BMW, 535d sport touring and M3 CSL, and would prefer a rear bias, but again they said that only the RS4 has 60% going to the rear.

The gearing is different on the tip, but to be honest it is for the better, crusing at 100mph in the manual sees the rpm at 4000 and the car using 14L/km, in the tip is is only using 10L/km, big difference.
I have a manual and this is the only thing I don't like about it, the fact 6th gear is so short, if they had made it longer the car would be far better.

The other niggles?
Accelerator pedal is too high, so you have your foot in a position where you get cramp, the A3 has a much better pedal that sits lower and is pivoted from the floor, coming from a BMW you will notice this.
Clutch, too jerky and the pedal is again too high, but not a problem with a tip.
Wallows too much at on cornering and fasr too soft, RS4 anti roll bar helps alot, and better suspension sorts it out a treat.
Far too quiet, doesn't have any bite to it at all, even with the window down you can't hear it, but again if you add an exhaust that sorts that one out.

[Emm]

Thanks for feedback! On the Audi tech spec papers for the S4 (available at AudiWorld), it clearly states a 60/40 bias for the manual and 50/50 for the Tip (from 2006 and on; for 2005 it doesn't specify) -- the "60/40" notice for the manual is even set in bigger type :-). Maybe the tech spec is wrong, I don't know, but that's what it says...

Regarding the gearing ratios (esp. final drive), isn't the general principle "the higher the numbers the better the acceleration (at the cost of lower top speed)"? Could the 2-3/10s of a second the Tip lags behind be directly related to the lower ratios (actually higher for 1-2-3-4, but lower for 5-6-FD)?

I never heard of Milltek before, but will have a look. You mention that good tuning gets you an extra 20 hp (in conjuction with an exhaust), but which tuner would you recommend? Neither MTM, Abt nor Hohenester seem to offer a remapped ECU for the S4, and I absolutely don't want any solution that involves physically altering the ECU (soldering a new chip), I only want to be able to flash the ECU as it is.

(I won't do anything to the chassis until I've had the car for a while and have gotten a sense for it, but if a change is imminent, a set of PSS9's seems like a good idea.)

[gIzzE]

I think 60:40 thing is more wishful thinking, no one in the UK or Germany says that any S4 has rear bias it only seems to be something that has sprung up in the States.

There are loads of tuners who flash the ECU in the UK, I don't know who might do it in Sweden. Is there not a Swedish based forum that could help you out with tuners?