Rear Cat Delete and X-Pipe Question

**ballinb5** · 11-07-2014 05:14 PM

Car is a 2013 S4 with AWE Catback exhaust (resonated).

My main goal is louder exhaust (hp gains from cat delete are welcome as well but I know its probably negligible).

Going to exhaust shop to delete rear CATS on the downpipe tomorrow.

Separately, I am considering deleting the center resonator or the rear mufflers...

Main Question: If I delete the center resonator, do I need an X-Pipe or can I run 2 pipes straight through without connecting?

Do the 2 exhaust 'banks' NEED to connect before exiting vehicle? As in, will it hurt the motor in ANY tangible way if they do not connect?

Considering 3 options AFTER deleting rear cat:

1) Leave resonator and muffler since chopping up a $1000+ exhaust is not preferred.
2) Delete resonator
3) Delete mufflers

Any input/feedback with reasonable logic is appreciated. Looking for feedback on potential for drone at highway speeds.

Thanks

EDIT: Removed the stock Resonators:

**Tuned4Rings** · 11-07-2014 05:23 PM

http://youtu.be/6rK_NNciODU

**ballinb5** · 11-07-2014 05:25 PM

Originally Posted by Q5 3.0TFSI

http://youtu.be/6rK_NNciODU

Thanks.

Any info on the setup?

**Tuned4Rings** · 11-07-2014 05:34 PM

Started with removing high flow cats put x pipe there and removed middle resonator keeping factory mufflers but didn't like the sound. Then put magnaflow single in dual out mufflers in place of factory mufflers and then loved the sound but was very loud and very bad drone. Removed x pipe and replaced with small dual in dual out magnaflow and love it. Not to loud inside but nice and deep outside. Will post more videos shortly.

**chaos2984** · 11-07-2014 05:44 PM

Can we say idiot. Y in the world would you want to hack up a 2k exhaust for. Also the car doesn't have 2 sets of cats just 1 set. Those are resonators on the down pipes. If I was you I would cut out resonator on the down pipes then find another factory exhaust and cut out the resonator and muffler and just have tips on it. Done and cheap and you can see that awe exhaust to cover all expense for the mind unless money is no object to you. But if that was the case I wouldn't have an s4. I dunno.

**ballinb5** · 11-07-2014 06:03 PM

Originally Posted by chaos2984

Can we say idiot. Y in the world would you want to hack up a 2k exhaust for. Also the car doesn't have 2 sets of cats just 1 set. Those are resonators on the down pipes. If I was you I would cut out resonator on the down pipes then find another factory exhaust and cut out the resonator and muffler and just have tips on it. Done and cheap and you can see that awe exhaust to cover all expense for the mind unless money is no object to you. But if that was the case I wouldn't have an s4. I dunno.

Thanks jack. I can always remove the downpipe resonators/cats for now and think about the AWE exhaust later.

**DGVR6** · 11-07-2014 06:18 PM

Originally Posted by chaos2984

Can we say idiot. Y in the world would you want to hack up a 2k exhaust for. Also the car doesn't have 2 sets of cats just 1 set. Those are resonators on the down pipes. If I was you I would cut out resonator on the down pipes then find another factory exhaust and cut out the resonator and muffler and just have tips on it. Done and cheap and you can see that awe exhaust to cover all expense for the mind unless money is no object to you. But if that was the case I wouldn't have an s4. I dunno.

He is just playing russian roulette with his catalytic converter.

**TSXCman** · 11-07-2014 06:39 PM

Don't be a Jackass and remove cats, it's irresponsible and you won't gain that much. Just do the X-pipe mod with the resonated peice and call it a day

**ballinb5** · 11-07-2014 06:45 PM

Can anyone confirm my main reason for posting so that others with the same questions might be able reference this thread?

Is the x-pipe required? Or can the resonator be deleted in such a way that the exhaust becomes a "true dual" exhaust all the way through (from headers to muffler)

Edit: Looked at the AWE website and it looks like the exhaust already has an X-Pipe:
http://www.awe-tuning.com/awe-tuning...wnpipe-systems

Will prob decide what to do when the car is raised and what the shop can do.

**jl87** · 11-07-2014 08:16 PM

As mentioned above, the downpipes have resonators in them, not catalytic converters.

The main reason for an x-pipe is to promote exhaust scavenging- basically creating a more complete combustion cycle from the engine. An x-pipe also changes exhaust tone.

If you look at the OEM exhaust, unless there's an x-pipe in the center resonator, it is a "true dual" as you call it and does not utilize an x-pipe.

If you already have a resonated AWE exhaust on the car, here are a few options:
1. Remove resonated downpipes and install OEM downpipes or OEM downpipes without resonators if you want to hack something apart.
2. Purchase non-resonated downpipes/try to trade in classifieds.
3. Leave exhaust as is but remove the rear cans (they attach with clamps and are easy to remove) and have the shop create the last section of exhaust with a simple Y for the tips.
4. Sell resonated system and purchase track edition or post a classifieds ad and see if someone would like to trade that thinks their track edition is too loud.

Hope this helped.

**Tuned4Rings** · 11-08-2014 05:08 AM

Originally Posted by chaos2984

Can we say idiot. Y in the world would you want to hack up a 2k exhaust for. Also the car doesn't have 2 sets of cats just 1 set. Those are resonators on the down pipes. If I was you I would cut out resonator on the down pipes then find another factory exhaust and cut out the resonator and muffler and just have tips on it. Done and cheap and you can see that awe exhaust to cover all expense for the mind unless money is no object to you. But if that was the case I wouldn't have an s4. I dunno.

Yup I am a massive idiot. The exhaust was done on my 2013 Q5 with no issues and same with my s4. The guy who does all my exhaust work has been doing it for his entire life but guess you know more than all of us. Funny how this forum can be so helpful at the same time some of the most rude people. Thanks again

**chaos2984** · 11-08-2014 05:18 AM

Originally Posted by jl87

As mentioned above, the downpipes have resonators in them, not catalytic converters.

The main reason for an x-pipe is to promote exhaust scavenging- basically creating a more complete combustion cycle from the engine. An x-pipe also changes exhaust tone.

If you look at the OEM exhaust, unless there's an x-pipe in the center resonator, it is a "true dual" as you call it and does not utilize an x-pipe.

If you already have a resonated AWE exhaust on the car, here are a few options:
1. Remove resonated downpipes and install OEM downpipes or OEM downpipes without resonators if you want to hack something apart.
2. Purchase non-resonated downpipes/try to trade in classifieds.
3. Leave exhaust as is but remove the rear cans (they attach with clamps and are easy to remove) and have the shop create the last section of exhaust with a simple Y for the tips.
4. Sell resonated system and purchase track edition or post a classifieds ad and see if someone would like to trade that thinks their track edition is too loud.

Hope this helped.

good info. I would not want hack up a nice exhaust like that unless like you said remove the mufflers on it and add instead straight pipe with twin tips. But If you want a truly loud exhaust. I would cut off front resonators on the factory down pipes and put in an Xpipe and then just run straight pipe back and thats it with some tips on it and your done.

Most people on here who do not want to spend the money on a true exhaust because its way overpriced, do the X pipe mod. Their are 2 ways to do the mod. First one is to cut out that center resonator, know as suitcase to some and put in an X pipe there. Ive only head video clips of that exhaust. But some others have cut off the front resonators on the down pipes and put in an X pipe there, then leave the center resonator and cut off the mufflers and add in pipe with just twin tips. I have heard that exhaust in person and it sounds great. Its not to loud for normal driving but as soon as you hit it, it gets loud. Ive heard it and it sounds good. I was going to do that mod but i came to be able to acquire a Full AWE exhaust with down pipes for an absolute steal with trade for a factory system.

But i guess its whatever you want to do. I just wouldn't cut up a nice aftermarket exhaust due to cost of it and or resale value. You could make one for much less

**ballinb5** · 11-08-2014 08:43 AM

Originally Posted by jl87

As mentioned above, the downpipes have resonators in them, not catalytic converters.

The main reason for an x-pipe is to promote exhaust scavenging- basically creating a more complete combustion cycle from the engine. An x-pipe also changes exhaust tone.

If you look at the OEM exhaust, unless there's an x-pipe in the center resonator, it is a "true dual" as you call it and does not utilize an x-pipe.

If you already have a resonated AWE exhaust on the car, here are a few options:
1. Remove resonated downpipes and install OEM downpipes or OEM downpipes without resonators if you want to hack something apart.
2. Purchase non-resonated downpipes/try to trade in classifieds.
3. Leave exhaust as is but remove the rear cans (they attach with clamps and are easy to remove) and have the shop create the last section of exhaust with a simple Y for the tips.
4. Sell resonated system and purchase track edition or post a classifieds ad and see if someone would like to trade that thinks their track edition is too loud.

Hope this helped.

Yes, thank you. That's exactly what i was looking for. I will most likely have the shop weld a straight pipe instead of the resonators on downpipe and remove the rear mufflers. Since they are clamped in i wont have to hack up the exhaust.

**jl87** · 11-08-2014 08:49 AM

One more thing to note on the x-pipe, the further upstream you can put it the better.

**drob23** · 11-08-2014 09:09 AM

Originally Posted by ballinb5

Can anyone confirm my main reason for posting so that others with the same questions might be able reference this thread?

Is the x-pipe required? Or can the resonator be deleted in such a way that the exhaust becomes a "true dual" exhaust all the way through (from headers to muffler)

Edit: Looked at the AWE website and it looks like the exhaust already has an X-Pipe:
http://www.awe-tuning.com/awe-tuning...wnpipe-systems

Will prob decide what to do when the car is raised and what the shop can do.

With a v6 you need to have scavenging between the two exhaust manifolds. With 3 cylinders per side, in a given exhaust manifold, you'll always have 180 deg (out of 720) of crank phase with no cylinder firing. So you'll hurt performance (via pumping loss) if you completely decouple the exhaust paths.

**ballinb5** · 11-08-2014 11:12 AM

Originally Posted by drob23

With a v6 you need to have scavenging between the two exhaust manifolds. With 3 cylinders per side, in a given exhaust manifold, you'll always have 180 deg (out of 720) of crank phase with no cylinder firing. So you'll hurt performance (via pumping loss) if you completely decouple the exhaust paths.

Ok thanks.

I ended up only removing the stock downpipe resonators and it sounds amazing. There is an x-pipe on the awe catback so i think for now i will leave the awe as is.

Will post video later