W12 Exhaust
 

Hi,

The exhaust system on the A8L W12 consists four tailpipes but al low engine speeds only two are active. The other two open when full throttle is actuated.

My question is can the flaps in the exhaust be made to remain open all of the time.....in effect increasing the exhaust note :o)

thanks
chris

Yes, just remove the flaps.

Don't remove the flaps...
 

they are integral with the rear muffler. Instead just pull the vacuum hoses that control them and cap those off. Presto, the valves are permanently open since they are designed to "fail" in that position if something goes wrong.

wonderful, that worked a treat

many thanks

I know this is a very old thread but I'm trying to do exactly this.

I've pulled the hoses off each side however the flaps remain closed, is there something else I need to do to actually get them to open and stay open?

Thanks.

Should be open...
 

If you pull the hoses on a U.S. W12, they stay open all the time. IIRC, folks w/ some S8's have occasionally reported they apparently stay closed as the default position. Perhaps non U.S. set up is different or even varies by year.

S8 default to open with no vacuum... I have installed a few Milltek Sport Systems on the D3 S8s and all have been the same.

Now Porsche vehicles, those can be tricky...

My US specification 2008 S8 with the stock exhaust defaults to closed with no vacuum.
I had to pin them open.

Pin? I had a Z06 and there was a fuse you could pull that would keep them open. A fella named Lou Gigliotti came up with a gear shifter that had a button wired back to the fuse box so you could open/close at will.

Interested in figuring this out as I purchased a S8 this weekend.......

Yes, I used hooks to pin the valves open, which normally are closed under spring pressure at low RPM when not acted on by vacuum.

Does this just increase the exhaust tone at all speeds then or what is the benefit here?

"All show, no go"
 

Yes, you are correct, it just increases sound at all speeds. The sound is there in full above certain RPMs and when you floor it, so it just gives more off idle and modest acceleration when the valves would otherwise cut off the bigger outlet on each side.

The "no go" part is it really is arguably a slight performance decreaser, not increaser. On normally aspirated motors, some increased exhaust back pressure typically helps low RPM torque. That is a cost on old world big pipe exhaust systems that of course are sized to reduce back pressure at high flows. But if you valve it like the W12 and a variety of other late model car designs (seen on other Audis now, BMWs, Vettes, and many others), you get a bit more low end torque plus more quiet, but have the freer flow when you get on it.

FWIW, I tried it briefly. Didn't find any magic sound elixir, and so I just put it back the way the factory designed it. At least on the W12, disconnecting it doesn't lead to any warning lights or obvious codes (at least if lines are plugged), so owners can do what they want with it.

You could just unbolt your exhaust

http://www.youtube.com/watch?v=EDYD0...ature=youtu.be

Can you drive it like that lol..?

yes. it is obnoxious.... and awesome

Yes, you can, i've done it. The car sounds like a supersportscar, and you should have seen the faces of a couple bikers, when i shut the car down in traffic lights, and fired it up again. The bikers almost shat their pants. :D

Tough, flooring the pedal, or otherwise heavy driving is extremely loud, so loud, that you can't talk to the person sitting in the passenger seat. :D

Somdude
 

pull that beast outside and shoot a video of revving and takeoff .... PLEASE...

It's time for electric cutouts....

Just V8 won't sound as good as W12.

I have W12 :D

http://www.f1-fansite.com/wp-content...ting_fast2.mp3

http://www.f1-fansite.com/wp-content...08/vocalf1.mp3

You got me......
 

Misha,

NOW THAT WAS FUNNY !!!

Thank You for the laugh.....:D:D:D

Kids want.
Remind me sometime of how a guy told a friend of mine that the 'fartcan' was the 'song of my people'.....

To those looking for sound - crack a window.
Cheap, easy, saves tons of money :D

Those darn German engineers knew what they were doing.

The stock w12 has absolutely no exhaust note