firewired

My car is just short of it's first scheduled service, so I wanted to find out if this is something to check before I bring it in.

Firstly I have had my RS4 since June 3rd, and I have two M3s that have similar "sport" button which similarly change the throttle mapping. On the M3s when you push the "Sport button" you knew it if you were accelerating at the same time you would feel it take off a little bit, as the effort to open up the throttle was remapped.

I have read repeated reviews of the RS4 where the "S" button in the RS4 is described as turning the car into another beast, and modulating the throttle is much more difficult making it hard to drive in traffic. I can definitely say that I am without a doubt able to hear the valve on the exhaust open and the wonderful exhaust note when I push the "S," but I cannot perceive absolutely any difference in the accelerator sensitivity. Is there really such a difference in the throttle sensitivity? Just wondering if mine is functioning correctly.

I figure even if something which is as unique as this to this car only were not functioning, they might not know it because there are so few of them around. Thanks for any insights.

VerrÜckt

I agree with you. I never noticed any major difference with the throttle response.

ELEVENS

Not much diffy here either, so I disabled the muffler flaps and no longer need the "S" button.

cgthanos

Driving without the S button feels a lot like the B6 S4 throttle mapping... it is easier in some ways but you become a victim of the DBW setting that was constantly maligned by S4 owners... you can transiently tap pedal to the metal and get almost no throttle response... switch to S and it lunges forward. downshifts and heel toeing in S mode also require much more precision IMHO, but the reward is much more control and instantaneous power transfer... the mapping in s mode reminds me of that in the 997S. Perhaps I am so cogniscent of the difference because the mapping was always my biggest complaint in the s4...

RI A6

In the European model, FSI means Fuel Stratified Injection. At low power, the fuel charge is shaped around the spark plug, with the remainder of the combustion chamber remaining lean. This gives the engine higher efficiency during low power crusing than we get in the states. But it is not used in the US, because of the high Sulpher content of our fuel.

In the American model, FSI means Fuel Straight Injection, where a full fuel charge fills the combustion chamber. In the US, this is done for all injections. In Europe, this is the mode used under heavy acceleration.

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Now, I am just guessing, but it may be that in Europe S-button throttle remapping causes the injection system to switch to full time straight injection and turns off the stratified mode. If this were the case, it would explain the extreme difference in throttle response that the reviewers have noted. With S-off, the engine is predominantly running in stratified mode, except during full throttle acceleration. With S-on, the engine is running like ours does. We don't see the difference, since there is probably very little difference in the throttle mapping in the US. In the US, we always feel the beast, and we get used to it and desensitized. Whereas in Europe, they only feel the full power of the beast when the S-button is engaged, and stratified injection mode is turned off.

But this is only conjecture on my part.

RI A6

Notice any difference between stratified mode and straight injection? Or have you had the opportunity to compare?

Bob W.

the difference in performance isn't AS noticeable as the difference in sound, but it is noticeable.

Silver Fun

Harder to modulate pedal if you let off the gas also IMHO.

S4gasbord

This is usually when I am too lazy to downshift to put it into the middle of the powerband.

BlkJet

first to second, its really jerky with the s button on. Anyone else have that?