Audi C6 S6 v10 Info Dump

A6 All/ S6 All
#61

Do we know what accounts for the very large power output difference between this engine and the R8/LP Gallardo 5.2L, as far as engine internals? I see that the compression ratio is the same.

Obviously one difference is that the S6 only revs to 6750, while the Gallardo keeps making power up to 8,250 RPM. I think it’s safe to assume that the R8/Gallardo V10 is equipped with different heads and camshafts. Could upgrading the heads to R8/LP units, paired with a re-tune, make up for a lot of the power difference? I would think so.

#62

you just answered it. In bold. The 8000+rpm redline requires extremely high quality materials for the moving parts, and head flow etc would be the least of your concerns if you upped the ante, upgraded heads, but crumpled your cast internals and had a catastrophic failure in the process.

CV once discussed the 7000 RPM redline present on many of these Audis as EXTREMELY expensive to manage vs. a 6500 RPM redline…the gap is huge with the speed. Taking that to 8000 or 8250 RPM…that’s a whole other ball game of difficulty and cost again.

#63

I am pretty sure that the V10 R8s rev higher than 8,250. I think their redline is 8,500 or 8,600 rpms. Definitely playing with fire going that high.

#64

What these guys said ^^^

To give you an idea of how close the engines are at 7000rpm and under, see this comparison of the Q7 vs RS4 (the S6/S8 vs R8 v10 is comparable)

http://ep1.pinkbike.org/p4pb11204213/p4pb11204213.jpg

According to the graph (which is from Audi Study Guide, so may not be 100% accurate) the two engines are only about 10-15hp apart at 7000 rpm. But by 7800rpm the RS4 has 70hp more peak then the Q7. You can expect the same type of thing when you compare the v10 engines.

More info on the 4.2s

http://ep1.pinkbike.org/p4pb11204221/p4pb11204221.jpg

#65

Weird… just noticed this

The stats show the RS4 at 420@7800. But the graph shows it at about 400hp at 7800. Which one is telling the truth ???

#66

I think I’ve read that the R8 has more then the RS4 I’d say 400 is correct. Did you see the weight differences? 30lbs more to the RS4. I’d love to know what makes up the 30lbs. You’d have to believe that those weight differences accounts for needed performance beefing up. You’d also have to think that the changes to the RS4 over the Q7 would be similar to what the Lamborghini and S6 motor beefing would be no?

#67

Sorry, I skipped the footnote regarding the weight difference

* with automatic transmission
** manual transmission including clutch and dual-mass flywheel

#68

There goes that theory

#69

This post I did ended up on the end of second page. Spent too much time for it to not be seen lol…

I bet they are properly sized. I installed K&N filters on the S6 that I did and they were the same size as stockers. Here is the info on them. Part number is E-2996

The flange the filter mounts to is 3.125"
The fliter itself is 6" diameter
The filter is 4.25" long.

Flatten that out and you have a panel that is almost 19" long and of course 4.25 wide. AREA: 80" (x2 filters so 160")
I seem to remember that the end of the stock factory filters are pleated and cone shaped, so that would add to the surface area of the filter.

S4 and RS4 filters are 10.3 x 8.25 so AREA is 84"

Thickness of the filter will probably make a difference here, but I suspect it is not enough to wash out the difference and put the V8 filter in the lead

Making up a measurement number for the hell of it. Square inches of filter per liter.
5.2 V10…30.8 per liter
4.2 V8…19.0 per liter.

SO the V10 filter sizes would appear to be plenty and not a major restriction. That airbox is tiny though. How much does a V10 S6 flow in CFM at WOT in optimal conditions?

#70

Thanks Joe! Ill add it to the body of the info thread so that it doesnt get missed.

#71

This dyno video is kinda funny at the end when you hear the guys reaction. From what I can tell, the S6 made 297hp and 316tq

https://www.youtube.com/watch?feature=player_embedded&v=TyiYpl5Tnlg

You have to listen for the guys reaction (probably the owner LOL)

The TQ seems pretty good, if the car is stock. I would guess these cars are at least 25-30% DTL, which, if accurate, would mean the TQ is higher than what Audi quotes at the crank 398 TQ.

The HP rating doesnt surprise me either. It is not that far off quoted figures after a guesstimate on the DTL. Down a bit probably due to carbon.

This is all assuming the car is stock. Usually when people dyno cars, they probably at least have a tune. Doesnt sound like he has an exhaust. Can anyone make out the company logo on the guys shirt? It looks like EPL, but I could be mistaken.

EDIT: I was trying to make out the logo on the guys shirt, meanwhile there is a giant EPL banner in the background that I somehow missed. Cant find any evidence on the web of a EPL tune for the v10 S6 though.

#72

Really exciting thread…

Makes me want an S6…

an S6 with a 6MT, Full Catless Exhaust with proper size piping, tune, intake, ported manifold and throttle body with manifold spacers, and some lw mods and these things will be beast…

No reason that it can’t make 420-430whp NA if the Lambo has done better than that… Especially with a 6MT swap…

#73

It is definitely cool to see all the interest this has drummed up. And when we finally get to the good stuff, I am sure we will get even more followers of the project.

I recently investigated the option of a manual transmission swap. The idea was killed for a few reasons

  • - The 6HP26A in the S6 is supposedly a pretty awesome transmission. Used in some Bentley and Jags, it has taken 600hp and more without complaint. There are reportedly very few failure rates according to ZF Technician TozoM8, compared to previous ZF tips. And again, in other cars, it is supposed to be very quick in shifting, and only shifts slow in the Audis. A nice tune should be able to wake it up.

    - When I started checking out the ZF used in the S6 and compared it to the RS4 manual transmission, I noticed something different right away. The front axle where the front driveshafts connect are right up at the front of the transmission on the ZF, unlike almost every other Audi transmission where they are a good eight to ten inches further back. This was designed especially for the v10, so that the longer engine was not further forward in the car. The back of the engine actually comes very close to the front axle in the transmission.

    The only manual I could find that does this was the one from the S5. And when I checked the shape of the front of the transmission to see if it would bolt up, it didnt look even close. It might work with an adapter, but now you are into a crazy one-off $15k project just to get a manual in a big sedan.

    Furthermore, to beef the S5 transmission up to handle 600 plus tq might be a stretch, and at very least costly. Again, you are going into unchartered territory. I’d rather take my chances with the 6HP26, and then do a performance rebuild if I blow it up. 517 transmission quoted me about $5k on a performance rebuild for the 6HP26. They said they can build it to take in excess of 1000hp. Hell, I paid that much for a rebuild of my first C5 A6 4.2 tip.

    - If I dump a bunch of money into the transmission, I want it to be ready for up to 750 lb ft tq. This is so that if I get a supercharger down the road, I know it will handle it. Having a bit of experience with the 01E conversions, I think that the manuals become a bit of a handful once you get into big power. You have to run a clutch that is not really comfortable for stop and go traffic in the city (where I do 99% of my driving)

    - Manuals are overrated :slight_smile: OK, so, I loved driving my A6 4.2 manual car. With the manual, you have a very direct feeling of the power. You also have lighter weight and less drivetrain loss. And, I think a big part of the fun comes from the simple fact you are using both arms AND both legs to drive. So, it is a more engaging driving experience.

    However, these new tips are so much better than the old. I can keep it in Sports mode, but then with a flick of the paddles, quickly gear down when needed. It will stay in paddle mode for a few minutes, and then go back to sports mode if I dont keep shifting. I love it! And it will only be a million times better after CV works his magic. The 6HP26A in the Euro only RS6 actually blips the throttle in between shifts to rev match. Just like the v10s, the Audi cars with performance manual transmssions will likely be extinct in the not so distant future.

So, after all that I choose to focus on other improvements for the car. I really believe the trans swap could turn out to be a $10 to $15k job in the end, with uncertain results. I would much rather dump that money into a built engine and auto trans, and supercharge the fucker.

#74

Sounds like you figured it out! Uncharted territory and expensive.

#75

The s5 can handle loads of power. But I think it’s irrelevant s it’s just too much hassle . Manual is overrated

#76

Good info!

Really interested to see how you like the tip after CV works his magic. I’m planning to drive up to Detroit to have him work his magic when we figure out a day that works.

#77

Awesome! I know when he logged mine he said there was definitely room for improvement inbetween shifts.

Here is a cool S8 video (same trans and engine as S6) with apparently the stock transmission and muffler delete. Shifts pretty damn quick as far as I can tell

https://www.youtube.com/watch?v=7bIqMyJrelc

#78

Sounds great… The 3-4-5 shifts seem normal, IIRC those shifts were always decent on a tip car, it’s usually the 1-2 and even 2-3 that are sluggish / delayed. Couldn’t really see how fast they were from that video. It will be perfect with the tune though

#79

Another crazy S6 v10 exhaust video clip

https://www.youtube.com/watch?v=sPBIcvsyQJE

I think this is my favorite so far

EDIT: Turns out the sound is significantly enhanced due to the acoustics of the dyno room. Only outside exhaust clips from now on!

#80

An S6 doing over 200 miles an hour

https://www.youtube.com/watch?v=Y2Qq6IKvGOE

EDIT: as pointed out below, looks like it is on a dyno