How to get a twin turbo V8 to sound good? Well that’s a challenge especially with a luxury sedan like the C7.5 Audi S6. If you want to improve your S6 Audi exhaust sound you need to brace yourself for a hefty price tag, but the real question is, should you buy a Milltek Sport Exhaust system?
00:00 Milltek Sport Exhaust intro and montage
01:16 Exhaust system for a twin turbo V8
02:02 C7.6 Audi S6
02:38 Stock Audi S6 V8 exhaust sound
03:45 Milltek Sport and AWE Tuning
04:52 What comes in the Milltek exhaust system
05:08 Installing the Milltek exhaust system
05:56 Milltek valved mufflers
07:24 Resonated or non resonated
07:52 H pipe or X pipe
08:32 H pipe sound versus X pipe sound
09:25 Audi S6 with Milltek Exhaust start up and revs
10:09 Milltek black exhaust tips
10:30 Issues
11:39 Milltek exhaust sound and crackles
12:48 Exhaust whistle sound
13:27 Is the Milltek exhaust worth it?
14:38 Outtakes and extras (RS5 vs S6)
16:13 Audi S6 acceleration
16:39 Audi S6 start up
17:17 Trying to film
The problem with turbo V8’s
Listening to this car in its stock form, it’s very subdued. The 4.0 litre V8 is almost hiding under the hood, buried beneath the turbos. It’s such a shame because it really can sound like a total beast!
After he bought the car, he and I went for a ride and both of us were like, cool, V8, but you can barely hear it. Granted this car is design to be comfortable with minimal road noise. But, if you are an enthusiast and you’re buying V8, you want to hear it.
So, going with a company that has high quality standards and equipment to fabricate this exhaust was a good place to start. We did try AWE Tuning, which is the North American counterpart to Milltek Sport, but they didn’t offer a valved system.
Another thing, all Milltek Sport products are 304L, or aircraft grade stainless steel. This means that for wear and tear, especially rust, you are getting a system that will last.
Installing the full exhaust system
With a few bolts and hangers removed, it’s actually quite simple to remove the entire stock system. You could do at home, but it’s always nicer in a shop with extra hands. The Milltek Sport system install is done in stages, first the headers, then center H-pipe with provided clamps, the rear muffler.
So what do you get with the Milltek Sport Exhaust Valved & non-resonated cat back system? In the box;
LH FRONT PIPE ASSEMBLY
RH FRONT PIPE ASSEMBLY
CENTRE SILENCER DELETE H PIPE
2 mufflers with valve controls
4 finished tips
Valved mufflers vs non-valved
So let’s talk about the valved system, they do cost more so here’s why I think you need them. Some Audi’s, like my RS5 and his S6, give you the option from factory, to equip valves which can be manually opened and closed. This lets you control if the exhaust note is louder and quieter.
Unlike my RS5, the Audi S6 has a fuel economy function which at certain cruising speeds, it will deactivate half of the cylinders. While this can be more fuel efficient, it sounds terrible.
Keep in mind, you are going to need 1 wiring harness extension. This is something we didn’t realize until after we ordered the system, so he drove around the first week with only a half valve open. So, remember, wiring harness extension, they’re about $25
H-pipe vs X-pipe
Next up is the resonator section or center muffler. Again, because we are going for sound, don’t waste money, the center resonator removal is going to give you a lot of volume so either get an H-pipe or an X-pipe.
We debated back and forth on this for a while. From what we could tell online, the X pipe was the way to go for the S6. The problem was finding a system that was configured this way. Our idea was, order the Milltek Sport valved, non-resonated, cat back exhaust system in full (which comes with an H-pipe), then separately, order an APR X-pipe and install it after.
So how does the Milltek Sport Exhaust system sound?
Ok, wow. Where to begin on this. For starters, it doesn’t even sound like the same car anymore, especially on cold starts haha. The H-pipe is quite perfect for the character of the S6. There is a lot of low-end rumble and it sounds angry as hell. The overrun, or pops and crackles, are hilariously addicting.
Whistle sound from exhaust
Drawbacks? Well, you might notice a faint whistle at idle or low rpm’s, we thought that might be a valve half closed, or maybe the waste gate from the turbos. Either way, you don’t notice it while driving and it’s very faint so not a problem.
Milltek Sport Exhaust Price
Yes, at nearly $4,300 it’s a hit on the wallet but bottom line, there aren’t a lot V8 sedans like this anymore, and if you are fortunate enough to get your hands on the C7 or C7.5 S6, the Milltek Sport Exhaust is a great way to open it up.
