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.