Downpipes for 3.0?

[smckay37]

C7.5 currently stage 1 APR soon to go sp stage 2. Have CAI and deleted rear mufflers. Happy with my exhaust sound but wondering how significant the performance gains would be if I added downpipes. Looking for real world feedback.

[scmtkings4]

Downpipes would be next to nothing. Power gains from downpopes itself will be very insigificant.

Switch yours out if they're showing signs of wear otherwise save your money for other more important things.

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[Valpo A7]

From what I have read at the various sites selling downpipes is you can expect no more than 10 HP from them. Seems that the "cat back" exhaust systems will net you about 0 HP as well since the stocks flow pretty good to begin with.

[sepheroth86]

I would guess that the most restrictive part of the exhaust system is the catalyst. Removing the cats is your best performance gain from exhaust.

They are also known to melt down over time and cause issues.

[scmtkings4]

I would guess that the most restrictive part of the exhaust system is the catalyst. Removing the cats is your best performance gain from exhaust.

They are also known to melt down over time and cause issues.Yup, the catted downpipes is one of the bigger restrictions and has the potential to clog over time

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[paul-g]

Guys doing stage 2 running mid to low 11's and dont have any exhaust work as it doesn't help much, with that said there is always a point... What you should do is upgrade cooler...way better way to spend that money.

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[Junkers]

If APR disables the secondary O2 sensors
https://www.aliexpress.com/item/32847650451.html?spm=a2g0o.productlist.0.0.70c52f6 a2d77TH&algo_pvid=3bf115f9-796c-4a17-a263-fbf793bb3806&algo_expid=3bf115f9-796c-4a17-a263-fbf793bb3806-0&btsid=0bb0622c16108402453303819efe41&ws_ab_test=searchweb0_0,searchweb201602_,searchweb 201603_
I wanted to test them out but i have IE stage 2 and they don't touch anything with the emissions.

[sepheroth86]

If APR disables the secondary O2 sensors
https://www.aliexpress.com/item/32847650451.html?spm=a2g0o.productlist.0.0.70c52f6 a2d77TH&algo_pvid=3bf115f9-796c-4a17-a263-fbf793bb3806&algo_expid=3bf115f9-796c-4a17-a263-fbf793bb3806-0&btsid=0bb0622c16108402453303819efe41&ws_ab_test=searchweb0_0,searchweb201602_,searchweb 201603_
I wanted to test them out but i have IE stage 2 and they don't touch anything with the emissions.

I am pretty sure that APR no longer touches anything emissions related. So, it would depend on when he had the flash performed.

Do those headers eliminate the cats altogether?

[Junkers]

Yes it replaces both the manifold and cat pipe

[Valpo A7]

Legally we are not supposed to remove the cats for a car that will be ran on the public roads. They are an EPA federal mandate. Emissions is a federal thing that has been delegated to the states to enforce. States were given the freedom to have or not have an emissions testing and monitoring program unless they did not meet federal EPA standards. Some states have a whole state test, some do not because they meet the federal standards. And then you have my state that has selective testing if the county does meet standards. I live in 1 of the 2 counties in Indiana that does testing.

But regardless if states test or don’t test, eliminated the cats is a federal law violation if caught. This rings true with the TDI crowd that does a DEF delete.

[joejoe3]

For those who gone catless, how bad is the smell in cabin?

[ANMS4]

For those who gone catless, how bad is the smell in cabin?

unbearable! And its winter time with the windows up :/. I have my car at my shop now install set set of GSI Sport cats EPA approved ( Green cats)

[joejoe3]

Yeah, the A7 is DD with the kids riding in the back at times.
No way I would like to expose them to the smell.

I'm keeping an eye on your build - hoping to find a setup as quiet as stock but able to keep the cats safe.

[ANMS4]

Yeah, the A7 is DD with the kids riding in the back at times.
No way I would like to expose them to the smell.

I'm keeping an eye on your build - hoping to find a setup as quiet as stock but able to keep the cats safe.

I'll be picking up tonight I hope, also doing resonated DP's AWE, really trying to tone my set up down, ( Older guy) and don't want it loud :/ .

[f4m0u5]

I'll be picking up tonight I hope, also doing resonated DP's AWE, really trying to tone my set up down, ( Older guy) and don't want it loud :/ .

loud!? u scared the shit out of my son lmao!

it sounds really good but yea was def a little loud haha.supprised how tame it was when driving behind you though, and i didnt smell the fuel from behind either

[scmtkings4]

I'll be picking up tonight I hope, also doing resonated DP's AWE, really trying to tone my set up down, ( Older guy) and don't want it loud :/ .Where did you weld your gesi cats? I have a set as well and I'm trying to think of where to put it exactly. Need to put it in the sweet spot where it won't melt, but still see enough heat for the cats to be effective

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[ANMS4]

under the car! As far away from the manifolds as possible I already melted a 2k set up in 6 months. I'll see if they or I can get some pictures

[scmtkings4]

under the car! As far away from the manifolds as possible I already melted a 2k set up in 6 months. I'll see if they or I can get some picturesYes, please let me know if you do get some pictures. I'm thinking about putting the gesi cats right in front of the baby resonators (on my 3.0 s5). This is for your a6 correct?

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[ANMS4]

loud!? u scared the shit out of my son lmao!

it sounds really good but yea was def a little loud haha.supprised how tame it was when driving behind you though, and i didnt smell the fuel from behind either

AHHA sorry about that :), I saw his face too LOL. Yea it's weird I smell it in the car all the time :/. Thanx man!

[ANMS4]

I'll have pictures today asked the shop to take some for me, the DP's didn't get there till 4PM :/

[ANMS4]

So the cats and the resonators don't fit., I'm not install the cats :/. Guess I'm stuck with the smell

[scmtkings4]

So the cats and the resonators don't fit., I'm not install the cats :/. Guess I'm stuck with the smellWhy doesnt it fit? Where are you asking them to weld it? I think a bunch of guys had that done already. Myself included, mine is at the shop right this moment getting it done.

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[ANMS4]

Why doesnt it fit? Where are you asking them to weld it? I think a bunch of guys had that done already. Myself included, mine is at the shop right this moment getting it done.

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Where did you put them. mine was putting them here? That's were the AWE resonators will sit

[scmtkings4]

Where did you put them. mine was putting them here? That's were the AWE resonators will sitThe cats are fitting there in that picture. Why aren't you going to keep them there?

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[ANMS4]

Then I cannot run the AWE resonators, that's where the resonators sit :/

[XLR8 Craig]

Guys doing stage 2 running mid to low 11's and dont have any exhaust work as it doesn't help much, with that said there is always a point... What you should do is upgrade cooler...way better way to spend that money.

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We have a customer (stage 2 IE 100 octane) who ran ~11.6 @ 122 consistently without a launch. He just matted it when the light went green. Definitely quick cars.

Couldn't agree more with the cooler statement. You are never going to see the full potential of the cars without that on there. Those who do not have it: they can cross that IAT threshold and start dialing power back with just one hard pull behind it.


If APR disables the secondary O2 sensors
https://www.aliexpress.com/item/32847650451.html?spm=a2g0o.productlist.0.0.70c52f6 a2d77TH&algo_pvid=3bf115f9-796c-4a17-a263-fbf793bb3806&algo_expid=3bf115f9-796c-4a17-a263-fbf793bb3806-0&btsid=0bb0622c16108402453303819efe41&ws_ab_test=searchweb0_0,searchweb201602_,searchweb 201603_
I wanted to test them out but i have IE stage 2 and they don't touch anything with the emissions.

APR Stage 2 testpipe files are no longer available to the public as it disables the rear O2s. Regardless as to what software you run, you would have to keep the CEL off with oxygen sensor spacers in the downstream. As others have stated when you turn off emissions components it creates EPA/Emissions issues.

When we do them in shop nowadays: JHM Cat Relocation and O2 sensor spacers in the downstreams. While it's still not the most emissions friendly, it is a good middle ground for those who are set on ditching OEM cats and getting a little more out of the car. Can pass a visual, has all the readiness monitors on, and keeps some of the smell out of the cabin (which can be pretty brutal).

Feel free to send me a PM if you need some pricing!

[Alabama]

Legally we are not supposed to remove the cats for a car that will be ran on the public roads. They are an EPA federal mandate. Emissions is a federal thing that has been delegated to the states to enforce. States were given the freedom to have or not have an emissions testing and monitoring program unless they did not meet federal EPA standards. Some states have a whole state test, some do not because they meet the federal standards. And then you have my state that has selective testing if the county does meet standards. I live in 1 of the 2 counties in Indiana that does testing.

But regardless if states test or don’t test, eliminated the cats is a federal law violation if caught. This rings true with the TDI crowd that does a DEF delete.

Agreed. The GESI website does not claim that EPA has certified the cats, just the following: "The key difference between models is our EPA Compliant catalytic converters have been third-party lab tested to meet or exceed local emissions standards in North America (excluding California) and will address Check Engine light issues with proper engine setup". GESI lists several "partners" who use their cats. APR has stopped selling downpipes altogether, AMS has a disclaimer: "NOT LEGAL FOR USE ON POLLUTION CONTROLLED MOTOR VEHICLES. THIS PRODUCT IS FOR RACING COMPETITION ONLY AND IS NOT LEGAL FOR USE ON HIGHWAY OR STREET VEHICLES, OR OTHER NON-RACING COMPETITION OFF-ROAD VEHICLES", and Kooks Headers is even more stern: "This is a RACE ONLY product manufactured and sold for installation on vehicles to be used solely for competition purposes. Once this part is installed, the vehicle may never be used, or registered or licensed for use, on a public road or highway. If you install this part on your vehicle and use the vehicle on a public road or highway, you will violate the Clean Air Act 203(a)(3), 42 U.S.C, 7522(a)(3) and may be subject to personal civil or criminal liability, including fines of up to $4,819 per day."