Pete_SQ8

Agent Boost
Here is a pic of my SQ8 rear exhaust section. No resonator and H pipe from factory

retom

The RSQ8 exhaust valves are controlled via the CAN network and their controller is integrated with other car system specific to this car. So the patent with an additional button may not work. Besides, the exhaust system is not just a few pipes and some metal cans. This is usually an engine-specific design and there is a risk that on a V6 you may not get the results you want with a V8 exhaust system. It can also negatively affect the performance of the car.
There are many workshops in the EU that build exhaust systems for a specific car model and customer expectations. This is not a cheap solution, but it may be less risky than self-experimentation.
You can always look at solutions from China. They make decent exhaust systems for many cars. Look here: https://de.aliexpress.com/item/10050...yAdapt=glo2deu
or here: https://www.aliexpress.us/item/32568...andl_shipto=US
Just contact them and ask. The prices are reasonable.

jayemko

Your guess is as good as mine! There's no rhyme or reason that I've found. VIN wont tell you, which is why I had to do a video under the car to prove my setup when I ordered both my exhaust and downpipe. While it might seem like the RedStar resonator delete might make sense, the Q8 would still be silent. Q8 doesn't have the vales the RSQ8 does, and the V8 helps the tone. On this point I can't disagree with you and the possibility, but as a Q8 owner I would tell you that it would be $1,000+ better spent on something else for the Q8 V6 specifically.

This sounds like a very Audi-response. Anyone knows that on an Audi, everything after the catalytic converters is for sound and to provide an exit for exhaust fumes. Catalytic converters are for emissions requirements, and removing them allows for greater performance from the motor (less/no backpressure) which is why there are catless downpipes. With that said, one could argue that a V8 muffler needs to handle more exhaust than a V6. So using a V8 muffler on a V6 (Audi) at WORST does nothing but provide no audilble difference and/or less back-pressure. I would agree with your concern about using a V6 muffler on a V8 (Audi) as the unknown design differences could impact/increase back-pressure and be a bad thing.

The valve is a valve, and can be controlled by whatever. One could look up specs (open/close voltage, PWM, etc) and get an appropriate controller. Will it look as clean as an RSQ8, and be integrated into drive modes? No. But a fob in the console you hit ON/OFF when you want is good enough for most.

retom

This is not the opinion of an Audi man. This is the opinion of a man who has been preparing high-performance cars for many years. Each exhaust system is designed for a specific engine. And these systems are designed by specialized engineers.
Of course, can you install an exhaust system from RSQ8 to Q8? Yes, you can. You can also install a muffler from a Toyota Prius. The only question is what will it give and what will be the negative side effects of such a swap. On the performance of the car, on its electronics or on engine durability, not to mentioning about environmental aspects (unfortunately many members of this forum don't care about it).

jayemko

And your wisdom and expertise in this forum is always appreciated. I’m just saying in this instance, exactly what you just said: you can. If the OP wanted precision engineering and to maximize performance, we could split hairs on a half dozen different exhaust systems. But the OP asked one question: “will it fit” and for one reason: sound improvement.

retom

Yes you are right. I just think the OP may have gone to a dead end. However, I believe it is worth to warn him against the risk of the lack of the expected sound improvement, side effects and costs. There really are many safer ways to improve the sound of the exhaust system. Like this: https://www.aliexpress.us/item/32568...andl_shipto=US
A friend of mine installed this kit couple of months ago and we were surprised by the product quality, its price and the sound improvement of his Q8. Seems that these Chinese guys know their profession.
Of course, at the end it's the OP's decision: his car, his money, his risk.....and his fun.

audiq4me

How are the valves opened and closed on that Aliexpress exhaust system??

jayemko

I agree. I'm actually running their downpipe as it was the ONLY one I could find for a Q8 (3.0). Impressive build quality.

Most controllers use a key fob for direct control with some using an OBD port plug in for varied valve opening (by rpm). If you can find a controller that utilizes the Homelink frequency, you could add the fob as a garage door in the MMI.

Hansi1234

So just a short feedback. The exhaust from the RSQ8 fits 1:1 to the Q8 55 TFSI. So now the next step will be to order the original server motor for the exhaust flaps (7PP.133.246.D) and the control unit to switch them on/off manually. From a sound perspective it´s for ME much better. Specially in comparisson what we had so far. But nobody should expect a sound like the SQ8, of course not, as it stays the 3 Liter engine. Seen that this costed me so far 300 Euros for the exhaust and approx. add. 500 for the server motor and control unit, i am quite happy. And its all original from Audi, specially here in germany this hopefully avoid stress with police.
Now i have to get power to the control unit, most likely from the trunk. But i could only find 1 way how to get the electric to the unit, and this looks like a bit complicated. I found a video explaining it from 7:49...so almost half trunk needs to be rebuild. Anyone a easier method to get power? I don not need to go to the control unit of the car (like seen in the video), i only need power most likely from the cigarette ligther...

Thanks a lot for your support so far...

jayemko

Unless you want to hang a wire over the bumper and close the hatch on it this is the only way. I installed mine this way but way before this video existed so I used service manuals. Was such a pain but it's the only proper way to do it.

It's not THAT bad. The worst part of any project that requires disassembly, for me at least, is the anxiety of the unknown: am I pulling too hard or not enough? Pull up or out? Etc. This is a cake walk compared to tearing down the console to properly clean a spilled cup of coffee.