the v10 s6 project

A6 All/ S6 All
#121

Definitely a great post.

As you probably know, I am giving people a chance to buy them at cost until June 30th. And still, I get the feeling that some people think we are making some profit on them. There isnt any profit with the current offer…not a dime.

Once the car is all bolted back up and on the road, I probably will arrange another group buy. But, the price will be higher, and we will need a minimum of five or six guys to make it happen. The people who REALLY want them, will get them now.

It is funny, we will probably sell a lot more catbacks, or even CAI, than headers. The headers are definitely the first place I would put my money (and the CountVohn tune). They resolve a lot of the critical problems with the car AND add a ton of performance. But, people are used to buying catbacks and CAIs. And they are a bit cheaper, and less labor. So that is what they’ll buy first. Not saying those arent great products, but the headers are the key piece to transforming the v10 S6 into something incredible.

#122

Looking great!! Are they going to sell the rest of the exhaust too?
I will let you know about the header purchase in 2 weeks.

#123

Thanks Nordy!

I think the catback (we keep calling it a catback, even though it actually goes further, and includes optional cats and O2 bungs) will be made available.

Right now, since it was built to match the headers, we could make additional sets that go with the headers.

However, to make a catback with an adapter that necks down to work with the stock exhaust manifolds, we would need someone with stock manifolds still installed, to bring their car in. Or, we buy a DEV car (if that ever happens).

In any case, if there is interest, let me know. Once my car is on the road and we have sound clips and performance data, I’m sure a lot of people are going to want the catback.

#124

I would love to go there. Just checked, and it is about a 90min drive from my Aunts place.

Problem is, I probably wont have a day pass until sometime in 2016. Dont laugh too hard, you’ll be in the same boat one day, B! LOL

#125

What you are doing is exactly what my plans were with my 08 s6 prior to a very unfortunate accident. I did a full custom x pipe exhaust at 2.75 diameter (to perserve tq) from the mid all the way to the stock mufflera. Also did msds or mss filters, new intake and new manifold. The car broke traction on dry pavement.

Anyways will these headers fit an s8, as I would like to pick up that project next as I miss my s6…have a cayenne gts but downer feel quite the same and I miss my v10!

#126

I’m not sure if the S6 headers would fit the S8. You would have to supply the S8, and have the shop build a set for that car.

Why dont you get another v10 S6? While a lot of this stuff could be ported to the S8 if you left your car with the shop for a few months, the S6 stuff is available NOW! And there is more coming in the next few months… stay tuned :slight_smile:

#127

I am fine supplying an S8, in the process of finding one :slight_smile: what are you asking for this set so I can see attached the realms of cost would be for the s8 header build…

Also curious on the reasoning you went with a 3.0 vs. A 2.75. I thought 2.75 dual was more than efficient for the 5.2 especially ti perserve the tq. Heck I even felt the csr was a little less tqy (not by much but a 100-200 rpm) after my exhaust install. Now if you are planning on force induction of some sort the 3 makes sense otherwise you don’t think it’s overkill. I could be wrong here by I believe folks using too large diameter piping 3ish were losing some power especially down low on my e60 m5.

Interested to hear your thoughts as I’m sure there was some science behind it. I’ll have no problem doing 3.0 if the overall power is there especially the tq. Just did 2.75 piping on my cayenne gts and that is 4.8 liter so while not a v10 it’s somewhat similar in size :slight_smile:

#128

Ill PM you the pricing on the v10 S6 headers and exhaust. If you wanted a set for the S8, it would likely be something like the price of the S6 headers plus whatever the labor and incidental costs are for removing/reinstalling the engine from your car.

The S6 guys are getting a break right now on the pricing, since my engine is already out.

As far as the exhaust sizing, the entire system was designed and tuned to achieve maximum power over a certain RPM range. If you have properly designed headers with a well designed collector, then you dont have to worry about a loss of torque by pairing it up with a free flowing exhaust. Exhaust velocity is what is key, and our long tube header design works to maximize that.

There is a great writeup on exhaust myth that ‘engines need backpressure to acheive maximum torque’

http://www.mustangevolution.com/forum/f312/t296628/

A dual 2.75 exhaust would have been good for up to about 560 hp. A dual 3.0 will remain efficient approaching 680hp, as part of a properly designed system

http://img.photobucket.com/albums/v413/nemo1ner/Exhaustguide.jpg

What’s interesting, is that the most popular exhaust for the v10 S6 (Millteck) is only dual 2.36", which is already borderline for stock v10 S6 HP. No wonder we dont see any real gains with that exhaust.

#129

What you said makes sense. And yes the mil sucks! I noticed a sig difference with my true x pipe 2.75; completely different car.

Excited to see your setup…if you don’t mind please pm me shop info etc. As I am serious about sending them a project s8 :slight_smile:

Also how big of wheels and tires can fit before major modification. I always wanted to fit 305 all around on am s8 but may be too much contact. I had 275 on my s6 and it for well though…

#130

PM sent

Regarding tires, I’m going to be going with 275/30/20s on the S6. I have no idea what will fit on the S8.

#131

10-4 275 is a nice size! A buddy was running lambo garrado wheels on his s6 with custom bracket looked pretty sweet!

:smiley:

#132

Sorry Gallardo*** :o ::slight_smile:

#133

The proper exhaust is a must for getting the best performance. If we learned anything its been the more rpm the more the audi loves exhaust size. The exhaust gasses start really getting serious over 6000 rpm. The v10 gets you close to 7000. At 6000 rpm your piston is coming up to TDC 100 times a second and your getting 50 exhaust pulses a second… now add that to over 5 cylinders and your looking at 250 exhaust pulses in just over a second on one bank.

The RS4 really gets a good bump in power with the 2.75 with the v10 giving 5.2 over 4.2 the extra size is just good insurance

#134

Well understood.

When I was doing my build I was planning for max of all motor 550-590chp so the 2.75 with proper x pipe performed quite well. At the sane time if I were to do a new s6 or s8 build now I’d consider custom headers and force induction so a 3 inch would make the most sense.

Also I knoe some of this back pressure stuff and proper size exhuast may be a point of conflict, but to everyone’s points above the design needs to be designed optimally in conjunction wuth the whole exhaust system from headers back as well as any additional force induction.

In the e60 world with the 4.9-5.0 v10 we saw people lose power especially low end tq over stock with poorly designed headers and/or catbacks. Food for thought. I am a huge advocate for x pipe exhausts and proper pipe sizing for applications hence why I do it on every car I own…

C/n: I want a full 3 for my s8 build coupled with turbos :slight_smile:

More importantly , what’s the latest on thus build since this is the topic :slight_smile:

#135

You hit the nail on the head… proper design of all components in the intake and exhaust track, are what can lead to the biggest gains in power. Guys like you and me have no idea what kind of consideration and calculation go into proper design of a system like this. Even the big aftermarket exhaust companies release expensive products that are not well designed, as you have mentioned.

  • What is the best grade of stainless to use for the headers and catback?
  • What is the ideal thickness of material for the catback?
  • What is the ideal thickness of material for the headers?
  • What is the ideal OD for the catback?
  • What is the ideal OD for the primaries for the headers?
  • Where exactly should the X-pipe be located?
  • How much should the two paths intersect at the X-pipe?
  • What angle should the paths be at when they intersect?
  • What angle should the header primaries be at when merging?
  • Should a megaphone be utilized in the header design?
  • etc, etc, etc

These are just some of the things that were considered during the design of the headers and catback for the project. Most of us wouldnt even have any idea of where to even begin, when it comes to designing a performance system for the v10. The guys who are designing the system are arguably the best in the world, when it comes to designing and building these systems for the Audi NA v8 and v10 cars. With the v8 S4s, their work lead to cars that broke all the records. So, I have a lot of faith that the finished v10 products will be top performers also.

#136

Great point A6 v8. Seeing some of this project and talking for years with the guys at magnaflow flow master hooker and with the local guys at Roush racing you see how the little things all add up.

The angle duration and location of the X is huge and when you realize that it might not fit in the most convenient location that just keeps adding to the details that others might not pick up. Also as vtgt picked up on was that you can loose power if your entire system isn’t built right.

Also just for the sake of conversation. Superchargers > turbos.
With a big v10 and mid to low rpm tq. That’s a huge win and great for everyday driving

#137

Agrew on the exhaust setup comments, but im on differing viww for the sc comment. I’ll also point out that an efficient twin turbo setup is more than ideal with this motor. The v10 is already torquy enough for me and if anything it doesn’t Rev up high enough due to trans etc. But higher revs with appropriate sized turbos would be fun. All things equal I’d prefer a well designed twin turbo setup over a sc setup. That’s just me tho, different strokes for different folks. Also if you look at the c6 rs6, I’m sure they had the option to use the 5.2 or 5.0 and simply sperchsrge it but they went with twin turbos.

Also, if you look at mercedes they have the sl55 which was supercharged v8 and then they had NA v12 in the 600 until 2003 which they then went twin turbo v12 as opposed to supercharged v12. I will admit supercharged tech has improved along the way, but just the oil wing those observations out there.

Any updates on this build, been quiet recently :slight_smile:

#138

The main reason why turbos are used so often in today’s cars in OEM applications because of their efficiency when determining fuel ratings. Superchargers are generally less efficient (although the Vortech centrifugal is pretty good).

If you want a twin turbo Audi, then buy a new S6.

Reasons why I would only go with a supercharger on the v10, and never a turbo

  • I hate turbo lag
  • With the headers, we are doing a ton of work to fix the poor placement of the cats and o2 sensors that cause excessive heat in the engine bay, and require an engine pull to get to. No way I am going to try and stuff a couple turbos back there, and deal with all kinds of problems that require an engine pull to resolve (if they even fit)
  • Two turbos - twice the amount of things to buy, and twice the amount of turbos to break. One supercharger in an accessible location up front makes WAY more sense
  • Superchargers have a more linear response, which I much prefer
  • Superchargers are easier to tune for. Who do you plan to have tune your twin turbo v10?
  • Twin turbo HEAT! Your v10 isnt hot enough already? ? ? LOL. Read the info dump and this thread again. Heat is the enemy with these cars
  • JHM proven track record with Vortech superchargers and the v8 Audis. How many twin turbo kits do you see for the v8 or v10 Audis that were successful? None, unless you include the UGR stuff that is designed for top speed, and starts at like $20k. Don’t try to reinvent the wheel. Stick to what has been proven to work
  • And finally, the biggest reason why I would NEVER put twin turbos on the v10, is it will ruin the glorious sound of best sounding Audi sedan that will probably ever exist… While the supercharger will only impove on it.
#139

As mentioned in the thread, the project is on hold while the drivetrain is being used to build headers for other S6 owners. There will be no further updates until at least August/September.

#140

Agreed and agreed, if were talking money a supercharger is much more efficient, won’t have lag, and much easier to maintain and heat will be less of an issue but still an issue none the less. The rs6 v10 still sounds great, and while heat soak is there I’ve seen run after run with nothing other than a tune and it still performs wonferfully.

If money were no object I’d still place bets on custom twin turbo setup with method injection. But your right if you want to retain mkr na feel sound maint etc. A super charger works great. But most every high hp project is a single or twin turbo setup :slight_smile:

CN: I’d rather not bother with either cause to your point both will add complexity, heat and maint, and when you have a glorious all motor v10 with 500hp and have actually cooled it down quite a bit why complicate things for another 50-100 hp (depending on boost)

Will keep you posted in my s8 project via PM. Look fwd. To additional updates form u in the fall.

No one was having convo like the list two years ago so I’m glad yall are picking up where I left off :slight_smile: