LOL
APR’s dyno charts are supposed to be fairly accurate, so I thought it would be good to include theirs for the v10 S6. NOTE :They have done a conversion to HP and TQ at the crank
http://ep1.pinkbike.org/p4pb11790420/p4pb11790420.jpg
What is interesting is that stock torque seems to be about 40lb/ft higher than reported by Audi (on 93 octane), but I dont know what numbers APR used to calculate the power at the crank.
Because Apr takes stock whp, then back calculates drive train loss vs Audi reported crank hp. Then they apply that drive train loss to their wtq as well…and to their modded whp/wtq to produce a crank chart for the European market and the non enthusiast market who doesn’t know what a dyno is.
If stock whp is low vs stock crank reported by audi IE the car is overrated or down on top end hp, it will artificially inflate stock crank torque in the back calculation…and will artificially inflate wtq and whp in the modded chart.
carbon cars look wonky when you use this method. An rs4 with carbon and or a vac leak that dynos 315 whp will end up with 25 percent drive train loss. Because carbon only affects top end the bottom end of the curve is fine. The peak torque usually occurs early in the unaffected area. When you apply a hugely inflated drive train loss determined by top end hp to the entire curve the unaffected areas get inflated. Namely low end hp and torque.
That makes perfect sense in this situation then. I assumed they would be using a freshly carbon cleaned car for their tests, but it is possible they didnt even know about the carbon issue when the tests were initially run.
Ill have to see if I can get a solid dyno to add to the dump.
So good of you to stay on top of this. Too often frustration turns into findings that aren’t true. Case in point the battery replace procedure.
APR is usually pretty solid in there results but as far as dyno numbers go all together it’s hard to really know what gains are really there. Dyno is a nice snapshot but there are so many other variables such as sakimano said calculations of all kinds that reduce the possible accuracy
More on Misfires
This is from a guy over on another forum. Ill thank him as soon as they approve my account over there.
[b][i]Lean running & occasional misfires
Postby barryrs » Tue Aug 19, 2014 3:16 pm
Just a quick note to let anyone suffering from the above faults what my fix was as there’s so little info out there on the S6.
I had faults come up for lean running and occasional misfires on pretty much every cylinder on both banks and set about tracing the problem.
A bit of searching around lead me to believe that it was a vacuum related and this can be checked fairly easily buy trying to remove the oil filler cap or dip stick with the engine running.
Example https://www.youtube.com/watch?v=cLSEgGtMatk
Knowing that the crankcase pressure was too high i began to look for the culprit with the following 2 options being the best bet after checking everything on top of the engine.
- vent pipe with check valve - 07L 103 217 B circa £40
- oil separator incorporating two-stage regulator - 079 103 464 D circa £135
The vent pipe is a bit of a nightmare as the entire inlet manifold has to come off to access it so i decided to try the oil separator first and thankfully this was the problem.
Upon removal (which is fiddly but not too difficult if you whip the throttle bodies off) we discovered that the spring operated piston over the cyclones was jammed in and you could blow back into the separator from the oil return pipe.
A swap over and reassembly has the car running smooth again and no faults being thrown up.
http://ep1.pinkbike.org/p4pb11802241/p4pb11802241.jpg
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I think the big thing to add to that is the lean conditions. The pcv system will cause ore issues on getting the car to run kean then misfire. I think it’s smart to add this to the check list but it’s not very likely to be the major cause of misfires.
All these pcv systems on higher mileage cars should be replaced and the system cleaned.
Thanks for the tips, Justin!
Hi All - great thread and great info.
I’ll add my small bit - not quite sure where to start!
Previously had an A6 3.0TDI, which was great. When we upgraded to the S6, it obviously felt much more powerful, but over time I sometimes feel like it’s a real slug. Whether this is due to be becoming dulled to just how it goes normally, or if it’s winding down, I can’t really be sure!
At 100k km, I had the short motor changed under warranty. The car didn’t have any real issues previous to this, but I though ‘new block for free - awesome!’ They did claim the three items which justified the work were: 1) oil consumption (which was maybe 500ml every 10,000km); 2) Metallic noise on cold start (I never heard this, all you can ever hear is the car idling like a lumpy bag of shit until the cats heat up, as we all know), and 3) metal filings in the oil (they had to get this inspected under a microscope - and of course all cars will have microscopic bits of metal in the oil! Else engines would last forever.)
When the engine was out, I took a ballpoint pen to the cylinder walls, and nothing caught but you could feel the surface was not perfectly smooth.
Before the short motor change, I had the car dyno’d and it made only 192kw/257hp (on a DynoDynamics), which I wasn’t very pleased with. I had always thought there must have been a carbon buildup issue, but they apparently serviced the heads while they were off and that includes a cleaning. This part I never saw for myself.
Since then, the story of my life has been exactly as everyone else here has noted. I have got multiple, random, intermittent misfires on idle - worst on cold start, in colder weather.
Either one of the cats or one of the O2 sensors is gone, as it’s also throwing a CEL.
Believe there’s also a leak in the intake manifold. I have lean on idle code, plus an intake flap stuck open error. So that puppy is coming out. The question is - should I buy a new one, or has anyone here serviced their existing manifold? Audi told me they are sealed with adhesive, so there is a chance of damage if you try to pull it apart.
And lastly - the other thing which interested me about this thread is the transmission programming. Any progress here? I think this would make the largest difference in performance, at least for my car. Sometimes it takes off beautifully, and other times it’s a total slug. I just wanted to check with you all before sending CV a pm.
The 6HP26 RWD version is used here in the Ford Falcon, and there are many gearbox tuning shops specifically for the Falcon, however none of them are willing to look at my 6HP26A! Apparently the difference is how you communicate with the box, but it would be great to know if the language was the same/similar, or is Audi drops their own in there.
Cheers
P
Wow, 257 on the dyno is quite a bit under what you should be at, I think. The lowest I have seen reported is about 270 AWHP. I would guess that a well running, carbon cleaned S6 should be somewhere around 300plus AWHP. I have seen reports of lower, and higher with a tune. I would say, don’t worry about the dyno reading too much for now, as your power should increase when you fix some of your issues.
That is interesting info on the short block replacement. It is important to know about that type of thing for the Info Dump, because I am interested in knowing if these engines have the same type of problems that are affecting the S4 and RS4 4.2s. So far, the numbers seem much lower, but then again the number of S6s is much lower. But that is awesome they gave you a new short block, in any case.
I think the 02 sensors and the cats that are located up close to the engine require engine removal for replacement. If that is the case, you might want to consider gutting the cats and possibly relocating the 02 sensors when you pull the engine. If you do either, youll almost certainly need a tune that accounts for the changes. First step anyway, if you want some help, is to pull all the codes and post them in a seperate thread in this section. Then we can figure out what things need to be fixed on your car.
I think I read somewhere that the intake flap motors are a known issue, and there is an upgraded part. Carbon buildup can also cause issues. If you have the time, I dont see why you wouldnt take it apart and try to service it. Wait for the Tech Experts confirm. Adhesive shouldnt be hard to replace. And Audi wants almost $2k USD for a complete intake manifold. Not sure if you can get it much cheaper with your discount.
If you pull it apart, detailed pics would be great to add to the dump. There is limited info on the manifold at this time. I would love to see what the inside looks like inside, to see if there is improvement to be made through porting.
Misfires and lean code… sound like the guys experience that I just posted. Check out this thread and see if it applies to you. http://forums.ross-tech.com/showthread.php?84-07-Audi-S6-5-2L-V10-MAF-sensor-logging&p=1301&viewfull=1#post1301.
As far as I know, the transmission is something CV is investigating, and a TCU tune is hopefully coming in the future. As for sluggish takeoff, it could be a number of things. Best idea is to pull all the codes from your S6 and post them in a dedicated thread in this section. There are some top notch Tech guys on the site who are very helpful.
Thank you for contributing to the Info Dump!!! Ill be following along with your issues so we can track them in the dump. Or, you can post your updates here directly.
Feels like a vac leak. He is down 70-80 whp.
Thanks guys,
Yes I have always thought it was down on power. I have had it since 70,000km, now at 146,000 - it has been at the dealer and Porsche/Audi specialists many times with no obvious vac leaks found - the last time it was at Audi they said they had sprayed a corner of the intake manifold (where the top and bottom parts are sealed together) with fluid and observed a change in idle speed which would indicate a leak - however the car feels the same as ever according the the butt dyno. No idea if this is a new or old issue!
I have a pretty good handle on what the error codes mean and what could cause them - except that the cat ‘out of efficiency’ and ‘lean on idle’ code doesn’t seem to say which sensor retuned it. Only bank 1 or bank 2.
Regarding the short block change - I am not convinced it was necessary, given what I saw in the cylinder bores - also keep in mind the dealer does make a lot of money on such repairs. Parts total alone was $57,000AUD.
If possible, I do want to gut the cats, and the tuner is looking to delete the O2 sensors. Can’t do much in that respect until the intake is fixed, and THEN have be able to handle the cost of dropping the engine to get at the cats.
Given that the fuel quality is apparently different here, there aren’t many RS/FSI guys reporting carbon buildup that I have heard of. Nevertheless something has stuck my intake flap open, and is possibly robbing power in other areas. I have the time, tools, and knowhow to remove the manifold and disassemble - but the car is the daily driver, so if I break something, or get stuck, my wife will get angry if I have to take her to work in a rental Corolla 
Was hoping someone had done it so I would feel a bit better in this respect.
A new manifold is pricey, yes, but aside from the issue mentioned above, I was also thinking of using the old one to see if anything like the JHM treatment could be done (flap shape, gasket matched ports, heat reflecting tape on the bottom etc).
If I take it out, I will post many pictures.
Another misfire report from kingfishgrapejam on Audiworld…
http://www.audiworld.com/forums/a6-s6-c6-platform-discussion-58/2007-5-2-s6-misfire-saga-2877024/
[b][i]Long story short, I was experiencing crappy performance at WOT and random misfire code at 123K miles. it was a Sat of course so I replaced the plugs with autolite iridiums (NGK’s weren’t available locally). Put every thing back together and car ran great…at low rpm. When I got on it, flashing CEL codes for cylinders 5&7. Replace coil packs…no luck. pull wiring harness covers off, no sign of broken wires. Finally I take electric connection cleaner and wd40 and douse the inside of the coil pack socket (harness side) and then prod a small piece of metal like a pin or in my case I used a VAG connector pin removal tool in and out of each of the socket connectors. Voila! ran the car for a 60 mile test loop around town and not a single miss.
So random misfire protocol for me now equals, Connector cleaning, spark plug check, coil pack replace. in that order.
Hopefully this saves some head scratching. Autolite iridiums seem to work fine btw, I gapped them to .32.[/i][/b]
Intake manifold rattle
http://www.motor-talk.de/forum/s6-5-2fsi-v10-ansaugbruecken-serienproblem-t4981070.html
According to this account on the German forum motor-talk, this is a common problem with the v10 S6s and S8s. There is an updated intake manifold from Audi apparently. The C version is the original problematic one, and the M is the updated one.
What happens is that the flaps within the intake manifold become loose, and rattle (the variable length intake manifold flaps, not the air tumbler flaps in the lower intake pieces). In the position for low RPM torque (long runner) they no longer seal properly. The poster says there is also the danger of the flaps getting damaged when they are loose and contact each other, and subsequently loose pieces being sucked into the engine. The guy also found reports of the problem effecting S8s.
He went to replace the intake manifold at a cost of 2000 EUR. Up until this point Audi denied ever hearing of the problem before. When he finally decided to purchase the new updated one, Audi said there would be no charge and gave him the M version for free as a goodwill gesture.
Everything that I have gathered was from a very rough google translation, so if anything is not exactly as written in the posts, please let me know. There are lots of great pics of the inside of the intake manifold and even some videos in the post. Ill try and copy some over when I have the time.
Here are a couple of pics of one where the flaps have actually broken
RS6 intake manifold fitment on the S6
If you were to consider adding forced induction to the S6, then it may make sense to ditch the stock S6 variable length runner intake manifold, and install the RS6. On an NA car, I don’t think you could beat the stock design, but once you add boost then the swap may make sense.
S6 intake manifold
http://ep1.pinkbike.org/p4pb11850631/p4pb11850631.jpg
http://ep1.pinkbike.org/p4pb11850632/p4pb11850632.jpg
http://ep1.pinkbike.org/p4pb11850633/p4pb11850633.jpg
http://www.jdengineering.nl/wp-content/uploads/2013/03/audi-S6-V10-engine.jpg
http://ep1.pinkbike.org/p4pb11850742/p4pb11850742.jpg
RS6
http://ep1.pinkbike.org/p4pb11850629/p4pb11850629.jpg
http://ep1.pinkbike.org/p4pb11850630/p4pb11850630.jpg
http://ep1.pinkbike.org/p4pb11850628/p4pb11850628.jpg
http://ep1.pinkbike.org/p4pb11850627/p4pb11850627.jpg
There are also the R8 and Lambo v10 manifolds, but after looking at them closely, I think it would be impossible to have them clear the stock hood.
Where the S6 intake manifold seems to be one large piece (that can be cracked open), the RS6 manifold has the upper plenum and runners, and the lower manifold pieces. The lower pieces look like they have the power flaps, or whatever you call them, that partially restrict flow at lower rpm. The lower pieces appear to be made from plastic, so I would assume will help reduce the transfer of heat to the upper manifold, something like intake spacers.
From the research I have done, it seems that the S6 5.2 and the RS6 5.0 share the same 90mm cylinder bore centre spacing and 84.5mm bore measurement. So, I will assume that the intake ports on the heads will probably line up. And from what I can see in a comparison of pics, most of the bolt locations line up too.
The heads themselves however, are different in their casting. On the RS6 heads, there is more metal material near the bottom sides of the intake port, where the S6 looks to have less material in that area. This would not normally be a huge deal, except that the RS6 lower intake manifold pieces have their gaskets built into the piece, unlike the S6 gaskets which are separate.
It appears as if the RS6 gaskets will not sit fully on the S6 heads, and the lack of metal will leave a gap at the bottom sides. Possible solutions would be adding some metal to the S6 heads to fill out the area to the bottom sides (like the RS6 heads), somehow making the S6 gasket work, or adding a transition piece something like an intake spacer (this may cause issues with the fuel rail fitment that seems to be attached to the lower intake pieces on the RS6. Maybe the stock S6 fuel rail can be maintained?)
RS6 cylinder head
http://ep1.pinkbike.org/p4pb11850634/p4pb11850634.jpg
http://ep1.pinkbike.org/p4pb11850627/p4pb11850627.jpg
S6 cylinder head
http://ep1.pinkbike.org/p4pb11850636/p4pb11850636.jpg
http://ep1.pinkbike.org/p4pb11850635/p4pb11850635.jpg
Also to note, it looks like the RS6 and S6 use the same throttle bodies, so those would hopefully bolt right up.
So, definitely not plug and play, and of no use with an NA engine. Might have value if adding forced induction, or possibly elements of the RS6 manifold could be copied for use in a custom manifold of an aftermarket forced induction kit.
Advantages
• Simpler internal design with less to break, especially under boost
• More compact, lower profile design (I think) - might be able to be flipped front to back
• Designed for an FI application
• Less heat transfer from engine
• Better looks
• Possibly quicker throttle response (would have to be tested to confirm)
• Removable plates on the ends that could be modified for use in a custom setup
• Possibly better flow with larger runners and dual throttle bodies directly attached to the intake manifold instead of combining into a single collector like on the S6.
• There is more space underneath the upper manifold to add a direct port NOS kit, and the separate lowers provide more options for installation
Disadvantages
• Cost (could be partially recouped by selling the stock S6 manifold)
• Complexity of installation
• May lose significant torque at low rpm off boost
RS6 Intake part numbers
Audi RS6 4F Upper Intake manifold 07L 133 223L / 07L 133 212F
Audi RS6 4F Lower Intake (07L 133 109P) and fuel rail (07L 133 315 F)
Audi RS6 4F Lower Intake (07L 133 110P) and fuel rail (07L 133 316 F)
Great info! That is a sexy ass IM on the RS6! Would Look even better a Direct Port N20 setup on it
would it be a bit crude to say that the difference between the S6/S8 V10 and the R8/Gallardo V10 is RPMs?
The S6/8 runs lower RPMs to the supercars, and has materials/internals that are suitable for sub7000 RPM levels accordingly…while the R8/Gallardo rev out to 8250-8500 RPM, and have the bulletproof internals to deal with it.
Also, the higher redline means higher hp output.
i.e. if both cars are at 340 tq at 7000 rpm, they’re similar HP wise at that RPM level, however while the S6/S8 ends there, the higher revving supercar engine can wind out to 8500. While it may fall from 340 tq to 320 tq at 8500 RPM you have 320 x 8500 / 5252 = 520 hp = R8 5.2
Very similar to the B8 S5 4.2 vs. the B7 RS4 4.2.
I think that is the perfect analogy, and the way I tend to look at things.
That is why adding an R8 or Lambo intake manifold really wouldnt do much good on its own, and would actually cost you a ton of torque down low. You need the high revving engine to make it worth it, and everything has to work together.
And the RS6 intake really isnt good for any NA car. It MIGHT make sense under boost, but even then the stock S6 intake might be better, depending on the setup.
When I started my research on these cars and people pointed out the similarities between the RS4 and the R8/Gallardo engines, I got a whole new respect for the RS4. I think that the B7 RS4 is an incredible car, and an absolute steal at the used car prices you can get them for. The same engine in the v8 R8, and the R8 is at least $80k. I think the general Audi enthusiast still thinks the RS4 engine is just a souped up S4 engine. When it is really so much more.
Really depends on the Cam profiles of each setup. A free flowing intake would use a more peaky cam profile and also rev higher. Audi did fine with the S6. our cars are heavy and need the torque down low and bring the HP in sooner and more flat. A lighter car doesn’t need the torque down low so they sacrifice that and make more peak HP at a higher rpm to stay in the HP from gear to gear at redline. Just my .02
Compare the 2 different power bands and see what Im saying.
S6 V10
http://i1348.photobucket.com/albums/p730/syncmaster347/52fsi_apr_vs_stock_93_crank_zps24c2b679.gif
R8 V10
http://i1348.photobucket.com/albums/p730/syncmaster347/52l_fsi_v10_r8_stage_1_93_crank_zps9909d5e8.gif
