Is this an active exhaust?

[infinitereality]

Decided to look at my exhaust tips again to find some bigger ones and noticed my car has the active exhaust on it. I have the window sticker for it and car didn't come with it, didn't think 2014s even came with it.

I tried all modes and it stays open. I searched out of curiosity if I can use VCDS to code, but not much info. Can anything be done to activate it?

IMG_20181227_150849.jpg

[widebodyfx]

Those are valves and in your photo above the flaps you’ll see the flap motors. Check to see if they are plugged in, maybe the car had a AWE or something not valves prior to being sold and the valve simulators are there to keep the codes from coming up.

Pre facelift S cars the valves are at the outer pipes, facelift S cars the drivers side valve is pre-muffler. RS cars never moved valve locations with the facelift.


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[infinitereality]

Those are valves and in your photo above the flaps you’ll see the flap motors. Check to see if they are plugged in, maybe the car had a AWE or something not valves prior to being sold and the valve simulators are there to keep the codes from coming up.

Pre facelift S cars the valves are at the outer pipes, facelift S cars the drivers side valve is pre-muffler. RS cars never moved valve locations with the facelift.


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Good info. I didn't dig around much since was just walking in, but there's wires coming off of the motors, just unsure if the motors have pigtails or plug directly on them. I'll get under there in a bit and see if I can see whats up.

Even though it seems to stay open, I still think the car is very quiet. Definitely want to track it down and get them working if possible.

[widebodyfx]

Pre facelift cars and non-sport facelift cars are all super subdued. Sport facelift cars have what looks like a straight through driver side muffler so the rumble is more audible to the driver when the valve opens using the path of least resistance for exhaust flow.


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[RAF_S7]

The facelift cars still have two valves, but they moved the position of the driver side valve. It’s now before the rear muffler (so you can’t see it by looking down the muffler tips)

[gk1]

All 4.0T's have the active exhaust valves S6/S7 RS7 A8/S8. It is more a function of the ANC to keep 4-cylinder mode noises at bay. In pre-facelift models S6/S7 they are always open unless in 4-cylinder mode, so it would be difficult to see them closed unless you have a camera mounted while driving or if they cycle briefly at startup.

"All the requirements regarding noise emissions in both 4-cylinder mode and 8-cylinder mode must be addressed. Because the acoustic and back pressure/engine performance requirements are clearly different for each mode, the 4.0L V8 TFSI engine exhaust system must satisfy both versions. This is made possible by a switchable layout using exhaust flaps. The exhaust flaps are closed in 4-cylinder mode. The exhaust system selectively reduces the low frequencies produced by 4-cylinder mode. Without this step, unwanted buzzing would be transferred into the interior that could not be eliminated by the ANC system alone.
In 8-cylinder mode, the exhaust flaps are open to the maximum. Flow noise and exhaust back pressure are reduced and the exhaust system sounds sporty.

The basic position of the exhaust flap at idle is different depending on the vehicle model. On the Audi S6, A7, and the A8, the flaps are open. On the Audi S8 (and I assume RS7), they open or close depending on gear selector position."

[infinitereality]

All 4.0T's have the active exhaust valves S6/S7 RS7 A8/S8. It is more a function of the ANC to keep 4-cylinder mode noises at bay. In pre-facelift models S6/S7 they are always open unless in 4-cylinder mode, so it would be difficult to see them closed unless you have a camera mounted while driving or if they cycle briefly at startup.

"All the requirements regarding noise emissions in both 4-cylinder mode and 8-cylinder mode must be addressed. Because the acoustic and back pressure/engine performance requirements are clearly different for each mode, the 4.0L V8 TFSI engine exhaust system must satisfy both versions. This is made possible by a switchable layout using exhaust flaps. The exhaust flaps are closed in 4-cylinder mode. The exhaust system selectively reduces the low frequencies produced by 4-cylinder mode. Without this step, unwanted buzzing would be transferred into the interior that could not be eliminated by the ANC system alone.
In 8-cylinder mode, the exhaust flaps are open to the maximum. Flow noise and exhaust back pressure are reduced and the exhaust system sounds sporty.

The basic position of the exhaust flap at idle is different depending on the vehicle model. On the Audi S6, A7, and the A8, the flaps are open. On the Audi S8 (and I assume RS7), they open or close depending on gear selector position."

Great info! Did not know this. Makes sense why they don't seem to close when I switch modes.

I wonder the difference between FL sport exhaust and regular exhaust? Different mufflers?

[widebodyfx]

A photo of the sport muffler on the driver side is in this thread. https://www.audizine.com/forum/showt...=sport+muffler

[gk1]

Great info! Did not know this. Makes sense why they don't seem to close when I switch modes.

I wonder the difference between FL sport exhaust and regular exhaust? Different mufflers?

Yeah, I think someone mentioned before the part numbers for the front section of the exhaust are the same between sport and non-sport exhaust. The only difference being the rear mufflers.