Project S6 2007

Hi, I’m new on here. I seem to kinda like Audis since I’ve owned 2 A6s (C5 and C7) and recently got an S6.

The car has around 200k miles on the clock, but the engine “only” has 100k.

It had several things wrong in the beginning, including a broken exhaust, vibration while driving, CEL, EPC warning, a loose control arm and some torn bushings etc etc. Probably not the most intelligent buy, but I got it pretty cheap.

Fastest car I’ve ever driven even with all the problems, and drove quite nice actually. I’m not very handy and the last time I’ve worked on a car was like 15 years ago, so I knew I would mostly have to have the work done by someone else.

Here’s what was done:

  • Wash !

  • Oil & filter change. Attempted this myself, but broke a coolant line in the process. Panicked and had it towed to a garage for repair in order not to break more stuff. Only later realized I could’ve pushed it to a parking space or even driven it home in that state, and the hose I broke was the tiny plastic one which I’ve now learned always breaks eventually.

  • New tires (less vibration)

  • Con artist workshop diagnosed all kinds of problems with it and changed a bunch of stuff that wasn’t really needed, and charged too much for it too: front brake rotors, some support arms, drive shaft, fuel filter, cabin air filter.

  • Spark plugs (noticeable increase in power)

  • Transmission oil change and flush (no problems encountered)

  • Fixed the steering wheel electric adjustment myself by using OBDEleven and doing its basic settings adaption. Now it moves in all directions like it’s supposed to.

  • Had the front window and headlight tint removed.

  • Interior clean and headlight polish + protection film

  • Fixed the exhaust. This was cheap. The welding looked pretty crappy and unsure about this job, but at least it doesn’t leak.

  • Carbon clean, injector inspection which resulted in all 10 injectors having to be replaced, new K&N filters (attempted to clean the old ones but used a hard brush before I learned you’re not supposed to do that so I bought new ones since the old ones were in horrible shape anyway) - noticeable increase in power again !

  • Changed a bunch more control arms etc, this time in a much cheaper and better workshop - by now almost everything in the chassis is new (not sure if chassis is the correct word, I mean the control arms etc)

By now I had found two nice workshops that are humanly priced and whom I can trust.

  • New wheels (finally cured the vibration while driving ! turns out the old wheels were not round anymore and had cracks in them)

  • Rust removal and new paint job (found someone to do it dirt cheap and they did a good job as well as far as I can tell). They also changed the front mask to a honeycomb one while at it, and fixed my parking radar by just replacing a 25$ sensor that I had bought myself (the con artist garage I mentioned previously wanted 700$ for the job - thankfully I refused).

  • JHM transmission & ECU tune (the transmission tune is great, ECU tune I’m not sure I can tell improvement over the previous APR tune)

  • Throttle body connector pins were tightened (the car had developed a problem where it would go to limp mode after almost every cold start). This fixed the issue, and later I had the connectors replaced altogether just in case.

This was the third workshop that seemed to really know what they were doing with electrics.

  • Nunoo Android multimedia player with touchscreen from AliExpress (actually great)

  • APR Coils and fixing a broken bolt in cat 4 + JHM Intake Heater Bypass. Not sure they actually fixed the right bolt since I haven’t looked under the car. The coils seemed to actually decrease power… I will change them back to OEM.

  • Custom 3" to 2.5" catback exhaust (noticeable bump in power!)

  • Custom S6 mats from The front mats are really nice, but the rear mats don’t seem to line up perfectly. Would still recommend as the quality is excellent.

What I have coming up:

  • Ceramic coating and renewing the awful chrome delete tapes and a bunch of other minor detailing

  • Fixing the threads in the intake manifold (currenty they’re busted and the manifold is epoxied in place)

  • Installing a set of new flaps in the intake from Currently the intake is gutted. There were all kinds of problems getting these into Finland since mail doesn’t currently run between Russia and Finland. I had to have these mailed to a friend in another country, then the idiot got thrown into prison right when the package was already being shipped, and they had to send me a new set to another friend, who thankfully came through and I now have the flaps ready to be installed.

  • JHM Intake spacers

  • JHM Lightweight crank pulley

  • JHM Lightweight brake rotors (I already have the rear ones on order

What I plan on:

  • Lighter wheels from Japan Racing (they weigh 2.5kg or 5.5lbs less than my current ones per wheel).

What I dream of:

  • Custom exhaust headers (this is gonna be super expensive to have done if I end up doing it – can’t gut the cats due to emissions)

  • Forced induction. I thought about VPS Verstärkt’s supercharger system, but read on here that it’s shit so I scrapped that idea. Turbocharging would be super difficult and expensive. Maybe an electric turbo at some point such as TorqAmp, which is meant to actually work unlike most of them…

Oh, the car is truly magnificient already by the way ! Everything works, it drives well etc. Really happy with it :slight_smile:

Good luck with your new project car!

Great start to the thread. Also top picks for performance and next step mods.


Sent emails to a couple of places in regards to the exhaust headers. Most places seem pretty reluctant to take on such a big job, and the one place that showed interest seemed too expensive. I could always just gut the cats, but then I would need an extra set of stock headers to put in each year for emissions testing, and it’s simply not realistic…

Maybe I need to find some place in Estonia since labour is much cheaper there… After all, it’s easy to get there via ferry and take it as a vacation of sorts.

Timing chain…?

The guy who made me the catback raised some concerns about my timing chain, and sure enough, I heard the small jingle he was talking about when I cold started the car after a few days of not driving it.

Been reading mixed opinions - some say it’s fine if it rattles for a few seconds after a cold start, others say you need to replace it immediately. Apparently this motor is not meant to suffer from many timing chain issues, and the garage who last serviced it said not to worry about it.

I’m having them take a closer listen when I get the intake manifold flaps installed…

Katsos, muitakin suomalaisia :smiley: Mikä meininki?

No mitäs Tässä :smiley: Ostin reilu vuosi sitten kanssa S6 ja on kyllä hyvä peli ollut. Kaikkea vaan pitäisi sille kanssa​:smiley:

Posting some project pics that I took along the way.

Here’s what she looked like when I got her

Vs now

JHM tunes getting installed

Flaps waiting to be installed. I expected them to be rigid, but the material is malleable. The material is PA12-CF30 (carbon fiber reinforced nylon). I have some doubts, but I’ll let the workshop decide on this one.

Custom catback ! (Excl. Mufflers)

Nice ! Aika vähän noita näkyy liikenteessä, en ole varma oonko kertaakaan nähnyt toista C6 S6:ta livenä. Vähän spessumpi peli ajella.

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Intake manifold flap failure. The shop said the flaps didn’t move at all after assembly. So based on this and the fact that the material seemed quite flimsy, I would skip this one… This was the repair kit from Russia.

It’s possible to make this flaps on CNC and then put them on shaft? Why they must be plastic with rubber edges? If they made from brass or something like on lambo, it should be working, or?

This is my thought as well. I will ask around some places if they can do it.

Thanks for giving this a shot and reporting back and giving a honest thought and end result.

As for the headers. You’re going to pay 2500 to 3500 and I’ll be honest it’s worth it as far as headers go poorly made headers are just a waste of money for no more hp. We’ve seen this over and over.

To be honest it’s been shown on here and tested that poorly made headers don’t make any more hp than the OEM manifolds less cats. So that’s something to keep in mind.

Yep, it was a failed experiment but at least the community gains more experience this way. That price range seems reasonable for the headers, but the one place that quoted me thus far was overpriced.

I’ve been looking into lightweight wheels for the past week or two. I currently have 255/35/19 all around. I could keep the same tires but buy lightweight wheels, or downsize to 245/40/18 to get an even more drastic reduction in rotational inertia. The only thing I’m concerned is whether 18s will look stupid on this car. Sometimes I feel like even the 19s at 255 look borderline too small for the body. What do you think?

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I think the A6 had 18 inchers, worth looking up to see

Forgot to mention the intake spacers and lightweight crank pulley are now in! There’s a new engine noise at 3-4kRPM, where it really screams. It might be intake noise or a harmonic resonance that used to be dampened by the heavier crank pulley. At first I was a bit worried but I’m sure it’s normal and I kinda like it.

The shop also told me again not to worry about the timing chain. They had a listen and said it makes absolutely no noise. They also told me there were a bunch of vacuum leaks in the intake manifold, which they fixed this time around. I’m seriously considering just dishing out for the new OEM manifold since they seem to be in stock in Europe again… I asked a place if they could fabricate just the flaps for it, but they told me it’s not as simple as one might think.

So what else is new? Oh yeah, I had the ceramic coating done, plus some minor detailing including alcantara wrap for the interior panels. I had several problems again with the place, the work was only “ok” at best, and today was the third time I’ve went in for an appointment only to find no one there! It’s almost unbelievable how they can be so bad at keeping track of their schedule, and completely unbelievable that they have a 4.8 star Google Review average. What a circus! (I still have to get them to remedy a few problems I had with their work, then I will never ever go there again and I will also tell everyone to stay away).

Otherwise the car is running great, no problems at all lately. Next up the lightweight rotors from JHM and lightweight wheels (Japan Racing SL01).

Just as I got through saying how well the car is running, she decided to surprise me with some fault codes :slight_smile: There were a bunch of misfire codes at startup, but I cleared them and they didn’t reappear. However, on the highway I noticed the EPC light flashed and there was a fault code “Cam position sensor bank B high input”. No check engine light.

This has happened once before, in extremely heavy rain. This time the car had been washed a day or two before, so maybe there’s a connection. I also paid attention that the engine sounded different when this was happening. The sound thing has happened a few times before, but without fault codes.

The cam sensor fault hasn’t re-occurred so far.

I had JHM’s lightweight rotors installed. At first I was worried the shop botched the installation since the pedal was squishy, but the feel returned to normal in a couple of days.

Lightweight wheels I ended up with JR SL01s in 18x8.5 ET40. Debating whether to put winter tires on already when I get them.

Edit: The JHM rotors look great. Old wheels still in place.

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Love that two piece rotor look. Great looking. And the weight drop is weight for a great performance improvement.

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I’ve been looking into the TorqAmp electric turbos ( It seems legit and some people have installed it on their cars on YouTube. I found a place that would do the install for me, but they explained that it’s not as straightforward as just bolting them in. You have to make room for the compressors and basically fabricate the intake path. Then the programming, which isn’t simple because they are on only part of the time. Plus bypass valves, wiring etc. Labor is what costs here in Finland. Then there’s the risk that it might not end up the way that I want, for example I’m concerned about the effects of the extra heat on power since there would be no intercooler.

I then asked about the headers, and they told me they can ask a couple of places if they will help with them. They would remove the engine and another place would make the headers. Let’s see what price they come up with. The engine removal was at a humane price, so if the headers aren’t too bad I’ll probably go with that option. There’s also an exhaust leak behind Cat IV which is causing some cylinders to run too rich, and this way that issue would also be taken care of.

They also recommended I do replace the gutted intake with a new one, so that’s on my list. @audis6 was kind enough to share me his dyno data on the broken vs. new intake and photos of his exhaust header setup, which I can use for reference.

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Holy moly !! 4.85s 0-100 km/h (62ish mph) !

The stock being 5.2s I’m really surprised and happy about this result.

I picked up P-Gear (similar to Dragy) and made some pulls. This is really great considering I still have some handicaps:

  • engine with over 160k km (100k mi)
  • gutted intake
  • headers with over 300k km (200k mi) clogging up the cats + exhaust leak causing lean codes
  • forgot traction control on
  • no launch, just mash the pedal

So basically this is with JHM’s tunes, rotors, pulley and spacers. Oh, and catback (non-JHM, but made by a reputable maker here).

NOTE! No 1-foot rollout in effect. Don’t know what the “corrected” 4.74s means, but I don’t think it’s that.

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Winter wheels & tires are in !

Combined weight per corner: 18.7 kg (41.1 lbs)
Japan Racing SL01 18x8.5 ET40 8.1 kg
Nokia Hakka R3 245/40 R18 10.6 kg

Compared to summer setup: 21.3 kg (46.9 lbs)
Rautamo R10 19x8.5 ET30 10.6 kg
Continental SportContact 7 255/35 R19 10.6kg

They don’t look way too small in my opinion, of course 19 looks better but these are lighter.

I was going to do pulls and measure the acceleration today, but she went into limp mode at startup. P3028 - Throttle drive 2 angle sensor signal implausible. Comes right back after clearing, so I’ll have to get it checked. I had similar issues with the throttle body in the summer, this seems related.

I think I have a problem with wiring, because I realized I have a few trouble codes that are all on the driver’s side.

Throttle drive 2 angle sensor (driver’s side): Implausible signal
Left electro-hydraulic engine mount: No signal
Bank 4 mixture adaptation range (bank 4 is on the driver’s side): No signal
Bank 4 O2 correction behind cat lean: Lower limit not reached

Bank 4 also leaks slightly behind the cat, and I used to attribute those codes to that, but I realized yesterday that a leak wouldn’t cause a “no signal” problem.