So far AWE is the winner in the exhaust world. Akrapovic came out with an exhaust (no pics), but its $7K and my rep tells me it doesnt have valves.
I am thinking I buy an AWE and welding in some valves.
Shouldn’t need valves if it’s a good exhaust. If it’s loud as duck and embarrassing enough that you need valves it may need a redesign.
Loud and retarded might fly on a fox body but anyone making exhausts for $80,000 audis that you then need to ‘fix’ is obviously a company that is doing it wrong.
Also what is the diameter of the awe? Last time I checked turbo cars like a big exhaust and a 4.0 that revs to 7000 does too. If it’s 2.5 (which all of their products seem to be) , it’s a big skip .
2.5 on awe
3" on milltek
[QUOTE=Zack/AWE;8653830]In regards to the 2.5" exhaust diameter, it was found to be the optimal size for a combination of sound and performance. This resulted in a civilized volume at part-throttle and max gains of 27hp and 31tq. For reference, the stock system is 2.36" and much more restrictive.
[/quote]
I wonder how true this statement is. For example, did they test other larger sizes but determine the gains were not worth the noise increase? As its a touring style exhaust product…
Still would like to know if APR did any exhaust testing. Hint hint.
That’s why they say ‘and sound’
Sound is subjective so they could make it any size they want and say they did it for sound.
Example: Stock rs4 exhaust is 2.61 downpipes tapering to 2.36 and 2.36 catback.
Capristo sells a 2.25 catback for $6,000 and says the same thing… 'optimised for performance and sound ’
Complete crock. They also claim gains of 20hp! Give me a fucking break. HOW? So slowing down the expulsion of spent gases with a restrictive catback is going to INCREASE power? And the morons on other forums eat this shit up. They like it because it’s exclusive and capristo has shiny floors and sells Ferrari parts. Unfortunately they’re dumb as a rock.
Truth? The optimal exhaust for a b7 rs4 is 2.75", all the way through. No restrictions. No 2.5" components to cut corners.
But…2.25 and 2.50 stainless is pretty common/cheap itself. A 2.75 high quality stainless is very expensive and putting together clamps, vbands, flex joints and mufflers that are 2.75 is also incrementally more expensive than the more common sizes. This is the real reason almost every audi exhaust is 2.25 or 2.5". They’re frankly not trying hard enough. So they just day ‘and sound’ and shovel it at the market.
Just wait till someone does their homework. Then look at the options presented. Buying because you want to buy when you’re early very rarely leads to a sound purchase (pardon the pun). The forums are full of guys in their second round of mods because they jumped at the early stuff that sucked (in b8 s4 terms, think mtm piggyback…or stasis exhaust…or the crappy restrictive intakes…or the cowboy revo tune )
One thing I am contemplating is buying the Milltek RS6 exhaust. 2.75", OEM Valves, resonated option, smooth bends, should fit. I could weld some tips on and call it good.
https://scontent-a-sea.xx.fbcdn.net/hphotos-prn2/t31.0-8/1912043_806539416029943_1089067807_o.jpg
https://scontent-a-sea.xx.fbcdn.net/hphotos-prn1/t31.0-8/1522787_806539419363276_2134851401_o.jpg
They also make downpipes with sport cats:
I am not in a hurry, just merely talking out loud if I were to make a choice today.
An RS7 owners on AZ cut off his mid muffler for a little more sound. Ghetto looking welds.
Milltek now sells a CAN to trick your car into thinking the valves are plugged in. Cylinder deactivation is preserved.
I am thinking milltek’s 3.0" cat back is the ticket.
I am going to start out with the non-resonated to start. If its too loud, I will add a valve to it.
http://www.jegs.com/images/photos/800/815/815-ec300d_1.jpg
Plenty of room.
http://www.millteksport.com/images/productnews/additional/216.original.jpg
They sell a remote control version so I don’t have to wire it through the cabin. I want to be able to force it quiet when I am starting it up in the morning or coming home up the hill.
I need more interaction with the engine.
Another shot of the bends.
https://scontent-b-sea.xx.fbcdn.net/hphotos-prn2/t31.0-8/1801286_603272716420610_928011762_o.jpg
Not bad. Routing sucks in teh first place, thanks to Audi.
Milltek has spotty quality history, so not sure how long that will last. Those tips…what’s the deal there? You said you could buy some? Why would you need to?
And historically, their cats are dogshit, so I’d avoid that. What are stock downpipes like?
Step 1) Buy Milltek Non-resonated C7 S6 exhaust. It is a cat back exhaust. Their sport cats are relocated in the stage 2 “downpipes”, that is what you see on the website. The picture I showed of the exhaust is a resonator.
Step 2) Install butterfly exhaust valve in one of the outlets coming off the muffler, essentially mimicking the stock valve. Valve is manually controlled by remote control
Step 3) Plug in error delete module for 4 cylinder to work
Step 4) Step on the gas.
The RS cars control the valve, and it opens when you go into Sport mode, closes id D mode. If I could do that, I would…as I want to go quiet when going around my neighborhood and on date night. I wonder if I could get someone to code that for me.
Stock exhaust:
http://farm3.staticflickr.com/2855/9166050815_702874a20a_b.jpg
I am going to basically replicate the RS exhaust package but go manual aftermarket.
Scroll down to see schematic:
http://audirevolution.net/forum/index.php?topic=2123.msg56135#msg56135
I just googled this post from AW.
In addition to 4 cylinder mode, it appears the valve closes in comfort mode above certain speeds at partial throttle.
Its too bad someone cannot rewrite the algorithm to close the flap during comfort mode like the RS models.
[QUOTE=Fairfax 4.0T;24445197]I’m interested in the ability to make the exhaust of my S6 louder in dynamic mode, and return it to stock volume in comfort mode. My hope was find an aftermarket muffler that had movable flaps, like the stock exhaust system, but was louder when the flaps were open.
First, I wanted to learn the control signals on the wires going to the electric motor that controls the exhaust flaps. This is explained in some detail in the Audi 4.0T Self Study Guide. Note that the link to the document appears to from one the Audiworld members, thanks!
Basically, the self study manual explains on pages 77-79 that:
Activation of the exhaust flaps is managed through the ECM. The commands “Open actuator” or “Close actuator” are issued using a PWM [Pulse Width Modulated] signal. Diagnosis
of the electric actuator takes place over the same line, also using a PWM signal.
Thus, it’s not a simple on/off signal, but a more complex signal that could not be applied to a generic exhaust flap mechanism. I though that this would be OK, because I could still take the control motor off the existing exhaust and put it on an aftermarket exhaust.
Here’s a picture from the 4.0 Self Study Guide of the motor that changes the flap position:
According to the self study guide:
Exhaust flap switching is map dependent. The following factors are considered by the ECM when calculating the map:
- Engine load
- Engine speed
- Gear selected
- Vehicle speed
Next I wanted to figure out when the exhaust flaps are opened and closed. I connected my Ross-Tech Vag-Com to the OBD port, went to the engine controller and monitored some parameters as I drove around, including the car speed, flap position, accelerator pedal position, and whether the engine was in 4 cylinder mode. [Note that the the current version 11.XX of the Vag-Com software doesn’t really work with the 4.0T, and I had to use the 12.XX beta to read/monitor/log the engine parameters.]
Here is what I found:
4 Cylinder Mode - Exhaust flaps are always closed when the engine is running in the 4 cylinder mode, regardless of whether the exhaust is set to comfort or dynamic.
Parked/Low Speed - Exhaust flaps are always open when the car is stopped or the car is running slow, regardless of whether the exhaust setting is comfort or dynamic.
Dynamic Mode - While I did not do complete testing in every possible situation, it seems like the exhaust flaps are always open when in the dynamic mode, unless the engine is in the 4 cylinder mode.
Comfort Mode - The exhaust flaps move to the closed position at around 65 to 77 Km/hour. When the flaps are closed and the car is coasting to a stop, the flaps open around 25 Km/hour. [Vag-Com displays the units in Km/hour, not mph]
Conclusion: Even if you could mount the existing S6 Exhaust flap control motors to aftermarket mufflers, you can’t get a loud exhaust and set it to a quiet mode using the MMI setting. The best you can do is have the muffler become quiet in 4 cylinder mode, and also in Comfort mode when the speed of the car exceeds about 70 to 75 Km/hour.
Oh well, I’m not going to pursue constructing an exhaust system myself any further, but it was interesting figuring out how the exhaust flap works, and what causes it to change positions.
Jim
[/quote]
[QUOTE=CreoSTi;9766659]I had a chance to install the Milltek exhaust valve delete modules tonight. Here is a comparison with the Milltek “modules” and the “caps” that AWE supplies.
The left piece with the blue ends is the AWE cap. The right is the Milltek module;
http://img.tapatalk.com/d/14/05/20/da6uzu7u.jpg
Here is the other side of the Milltek module, which shows metal pins;
http://img.tapatalk.com/d/14/05/20/garysu9y.jpg
The AWE cap is missing said pins;
http://img.tapatalk.com/d/14/05/20/asupumav.jpg
So that seems to be the difference between the two. The Milltek module has the pins that probably act as a jumper to connect the circuit.
I cleared the soft codes with a Vagcom, and I’ll re-scan in a day or two after driving a bit (to confirm the modules work/soft codes are gone).
[/quote]
It appears there are only three pins at play: power, data, ground.
https://farm4.staticflickr.com/3665/14272400672_e3b49544fb_c.jpg
Flapper Schematic by well_armed, on Flickr
I am to wire a cheap switch to control the valve for manual control.
I would still run the Milltek adapters to trick the ECU, but have manual control over the exhaust. This would allow it to be closed during cold start or coming home through my neighborhood.
http://i.ebayimg.com/21/!Bk+1FiQBmk~$(KGrHqQOKj4Es9y1IMQFBLZ0oK0RNw~~_12.JPG
My plan is to buy the RS7 non res exhaust, as its the same part number as the RS6 exhaust. Weld on some tips, and go.
As you can tell, its Exhaust Research Weekend.
Or I can just do a side dump
http://store.racereadyperformance.com/assets/images/ec250d300dkit.jpg
Apparently they have changed the S6 design from this:
https://scontent-b-sea.xx.fbcdn.net/hphotos-prn2/t31.0-8/1801286_603272716420610_928011762_o.jpg
To this:
I asked Milltek why they changed, and John actually replied.
[QUOTE=John@Roc-Euro;9783283]1: Shown on the top is the new Non-Res. Shown on USPs site is the old version. I do not believe the old version is available any more.
1a: I switched the resonator placement because I spend time testing variants to see what works best. Deleting the center res brings cabin noise up without bringing exterior noise up. No center res = some drone. By retaining the center res, and deleting the rear mufflers, you have excellent interior volume without ANY drone inside, and it sounds pretty beastly outside. This overall is a much better solution.
This is exactly what I did with the B8 S4 to attain the same goals. [up]
1b: Adding a valve would be moreso dependent on your end goal, based on your starting point- the valved rear with no center res will be ok cruising, and nice and loud opened up. But it will have more interior drone than the version with the center res. IN a perfect setup, I’d (personally) use a valve in the center to bypass the center res (with no rear mufflers) allowing nice and pleasant interior cruising sound, and basically straight pipes when the valve is open. But thats just me.
-
True story, some people really want big ass pipes, and some days I think that’s all that drives sizing. However, if the 3" tubing sounds best on the S6, and 2.75" tubing sounds best (and flows ideal) for the RS, then it is what it is.
-
I have not tried putting the RS7 system on the S6, which truthfully, is because I think the S6 system sounds so damn good as is, that I wouldn’t bother with a more expensive valved system, personally.
3a. Which is also why I would be curious about fitting the S6 system to the RS7. [up]
[/quote]
Here was my reply:
John, first thanks for taking the time to reply to my inquiry for Milttek. I appreciate your feedback.
I think I understand what is going on with the center resonator, drone, and noise. Problem is, I am afraid that the non resonated version is too loud in its static form, even without a valve. So to do a cutout before the center section (making it louder), does not apply to my objective.
Resonators often are the cause of drone, so I wonder if the front pipe resonators are causing problems and need to be cleaned up buy a center section. Either way, I am thinking that I start with the RS7 non version as I can add the center section later if its bad. I also think the smaller diameter is going to be quieter.
RS7 Non-Resonated: $2,799
Wireless Actuator $110
Milltek Resistor $120
Labor: $200 to install tips (I’ll do the electronics myself)
Tips: $400
Total: $3,629
Positives: OEM Valve, 2.75" OD, smoothest bends and flow
Negatives: Too loud baseline, might drone with valve off. Hard to program OEM valve? Headaches with actuator, etc.
Now if I were to go the S6 route with 3" piping, I would probably go Resonated to be safe and add a Valve to the end.
S6 Resonated $2,799
Wireless Actuator: $110
Afternarket Valve Kit to Retrofit: $440
Milltek Resistor $120
Labor: $400
Total: $3,869
Positives: Largest OD @3 inches it should flow better, but I bet this is negligible with the banks separated. Quietest baseline sound.
Negatives: Aftermarket valves.
Now if I have to buy the center section to the RS7 kit to eliminate drone and quiet it down, I have $200 to play with in cost.
So far my vote is non resonated RS7 and retrofit a remote onto the OEM valve — adding the center resonator section later if I need to quiet it down.
I am going to do the RS7 resonated system.
A) It has a baffled muffler chamber to handle the valve, just like Stock. Picking the S6 system wouldn’t work. It needs the chambered baffle to truly create a “quieter” environment without screwing up the exhaust pulse.
B) It utilizes the OEM valves, which will be easy to program with a cheap electrical switch.
C) Maybe some day someone makes a CAN module to handle the valve in a couple years.
D) If I don’t like it, I can put it on my dads RS7.
Its actually cheaper to order from the UK right now:
http://milltekexhaust.pumaspeed.co.uk/Millltek-Sport-Exhaust-Audi-RS7-RS7-Sportback-4.0-V8-TFSI-biturbo-Cat-back-SSXAU364_16442_2_124_459.jsp
Gonna do a bank wire tomorrow am, get this party started.
Think I am going to do some dry carbon looking tips. My buddy with an M5 actually did these, but yes, another AZ has these on his S6. 
Apparently Griffin has some monopoly power with their U.S. distribution business through warranty work. If you buy from the U.K. and they ship, its grey market and no warranty work will be honored.
Just thought it interesting to know. So I ordered an RS7 resonated version from Greg with valve sonic in the rear mufflers, which have OEM valves pre welded in. I also ordered some S6 tips to bolt onto the unfinished tips.
I am going to utilize the Milltek resistor into the factory harness, and power the valves via aftermarket wireless actuator switch. Shouldn’t be too hard. There is a power, ground, and 1-way data wire, just need to read the voltage on the power and ground when open and close and duplicate. This is a half baked, but it should give me full control over the baffles on command. I might have my local electronics shop (Systems Unlimited) help me out, just so it comes out clean and the first time.
http://store.racereadyperformance.com/thumbnail.asp?file=assets/images/imag0112.jpg&maxx=300&maxy=0
Welp, got some new intel today on the Exhaust Chronicles.
Milltek has a shop S7 and tried fitting the RS7 mufflers onto the car. Said it took too much work and energy (as the muffler’s chamber design is lined up with the outlets, and moving outlets is not easy.)
Another fact is that Milltek is apparently working on a baffled design for the S6, and is apparently only a “Few weeks” away from release. However, I am not going to hold my breath on that one.
Edit: Just ordered non resonated version from Leo at EuroTek Tuning in Nevada.
If its too loud, I have planned out a few options (A) add the newly manufactured S6 baffled mufflers onto the system later (for a hefty penalty I’m sure) if they do indeed come to market, (B) Buy the now for sale Milltek S6 Muffler sections, cut them up and put V bands on so I can easily go back and forth between “Race” and “Touring” modes © Buying some RS7 mufflers and going through the hassle of remounting the tips, last (D) Have BBi make me a baffled muffler. I like my options. Done.
So I am getting the stock wheels painted black by a local wheel guy, so I decided to move the FJ out of the bay and throw the S6 on the lift and check out the exhaust. My milltek comes tuesday, wheels will be done same day, so it will live in the air over the weekend.
https://farm6.staticflickr.com/5545/14273507879_f25a7837d7_c.jpg
Untitled by well_armed, on Flickr
https://farm3.staticflickr.com/2911/14437043956_c8d03d0e22_c.jpg
Untitled by well_armed, on Flickr
https://farm4.staticflickr.com/3902/14458782102_72f242327c_c.jpg
Untitled by well_armed, on Flickr
https://farm6.staticflickr.com/5489/14460147015_e3d8a1d60e_c.jpg
Untitled by well_armed, on Flickr
https://farm4.staticflickr.com/3886/14458777012_c561731224_z.jpg
Untitled by well_armed, on Flickr
I have a leak on the center resonator.
https://farm3.staticflickr.com/2929/14437041836_47927b4131_z.jpg
Untitled by well_armed, on Flickr
https://farm6.staticflickr.com/5593/14273902387_dbb3933725_c.jpg
Untitled by well_armed, on Flickr
Those are some beautiful crush bends, Audi.