UrS4boy

Tired of searching for individual exhaust system components. Time to consolidate info:

The exhaust system starts at the head, with its five exhaust ports (note location and number of the exhaust manifold studs, there are 16, one is hidden):


Photo courtesy of Tom S. of RS2 America fame

The exhaust manifold to head studs are Item 9 in this diagram:



The OE 3B, AAN and ABY manifold and gaskets:



The OE 3B, AAN and ABY Manifold has runners from Cylinders 1 and 5 that rise up to connect to the EM just under the WG flange. This is not good for flow and may be a cause for burning exhaust valves on 1 and 5 when adding a chips set, e.g. MTM Stage 1+ without changing the EM for an upgraded unit, e.g. RS2 manifold:


Photo courtesy of Tom S. of RS2 America fame

Here is a photo that shows the RS2 EM on top and the OE AAN (and 3B and ABY) EM on the bottom to show the difference in the way cylinders 1 and 5 are handled:


Photo courtesy of GoHeels on Audiworld

Here are some OE AAN (and ABY) EM flow numbers courtesy of 034:



The RS2 Exhaust manifold is much flatter and eliminates the two separate runners from Cylinders 1 and 5. This is a serious upgrade from the OE AAN exhaust manifold.




RS2 EM Flow photo courtesy of 034

RS2 EM PNs:



Installation of an RS2 manifold requires some studs to be shortened:



Other options include the Wagner/034 RS2 HO manifold and a cast log manifold from STR. Beware that all of the aftermarket OE manifolds including the RS2, the Wagner EMs and even the STR manifolds have been copied and are out there on eBay to catch the unware.

The Wagner/034 RS2 HO manifold:


Photo courtesy of 034

An STR cast log EM:



The AAN exhaust system after the exhaust manifold includes the WG dump pipe connection and a down pipe that starts out as a single pope but splits as a "Y" and goes to the two catalytic converters(Note: The "Y" portion of the downpipe comes with a metal insulation cover when new. By now, most of these have corroded and fallen off, at least partially. Common source of rattle). Here is the C4 front exhaust details:



Here is the 3B S2 equivalent:



Here is the ABY S2 equivalent:



Here is the RS2 equivalent (note: the down pipe is bigger than the ABY in the A80Q chassis):



Here is a photo of Dan T's (Ringbearer's) old OE AAN downpipe "Y" and catalytic converters showing the last reminant of the OE insulation cover:



Here is some C4 AAN middle and final exhaust system info:





Here is one photo of the C4 AAN exhaust system:


Photo courtesy of dustovich in Edmonton Canada

Thanks to those not named who posted up the photos and diagrams used in this post.

GoHeels

More great info Dave. Reading this makes me want to break out my CC and charge up some
new Audi parts - I need more flow dammmit . The Wagner/034 RS2 HO manifold #'s look
awesome, and I'd love to drop the weight of my OE exhaust with a new modern upgrade.
I'll add a similar RS2 EM picture that includes some of the necessary hardware.

(RS2 exhaust manifold and hardware)

dustovich

Here is another picture of a stock AAN C4 exhaust. Just so happens to be sitting on the floor of my parents garage. It is also for sale.

dustovich

Any info on the sport quattro evo mani? For an extra 100 dollars that can be had. Would it work with the standard downpipe, etc, etc.

UrS4boy

While the Wagner RS2 EVO manifold is pretty much plug and play RS2 replacement, the Sport quattro EVO requires a bunch of changes, i.e. new air filter location (OE air filter box is eating turbo) and a new custom downpipe. Only needed if you are going big, i.e. GT3071 and above, e.g. GT35. By this time you need to have replaced the rods with stronger ones so it becomes a huge money pit.

UrS4boy

If you can break it down a bit and get it in a box (or boxes) for the Greyhound, I could have a buyer for it down here in Vancouver.

In the meantime, I am stealing the photo (credit to you) for the exhaust post. (Thanks).

dustovich

I was going to break it down the last time I was there but those bolts are on there quite tight, might have to grind them off. Ill be at my parents in a couple weeks, pm/email me and we can talk.

scarman

Cut the bolts off and save any hardware other than nuts/bolts, i.e., the springs/spacers/washers. The bolts are probably overtorqued or will be by the time you could get the nuts off.