Cat Delete?

MrHarris · 03-08-2009, 05:30 AM

If I remove the cats on the x-pipe and put straight pipes, would I get similar gains to an aftermarket x-pipe like AA or Encore?

Sticky · 03-08-2009, 06:53 AM

Similar? Yes...

J08M3 · 03-08-2009, 09:37 AM

I think a big part of the reason you see gains with AA x-pipe is because it forces you to get their ECU tune also so it's not just as simple as eliminating a secondary cat. I would expect close to no gain if you only eliminate your secondary cat. Sure it provides some restriction to your system, but it's minimal and will affect sound more than power.

boostedtwin · 03-08-2009, 11:34 AM

The main restriction are the primary cats... Remove those bad boys and you will notice a difference. AA removes both primary and secondary with X pipe.

Bx Tpr · 03-08-2009, 04:24 PM

Quote:

Originally Posted by boostedtwin

The main restriction are the primary cats... Remove those bad boys and you will notice a difference. AA removes both primary and secondary with X pipe.

The more and more I read about the AA mid section the more I think it's totally worth it. You keep your OEM mid section intact and preserved so when it's time to part ways with the car you can just slap it on and sell the AA mid section.

J08M3 · 03-08-2009, 04:34 PM

AA is real expensive. But I've been researching it lately and they seem to have the best option available. I still don't understand how an x-pipe can be so much? But everyone says their quality is top notch. The fact that it's straight bolt on is nice too. If I end up pulling the trigger on a x-pipe AA is the way I'm gonna go. More for the sound of it combined with HFC and Eisenmann sport than the power increase. Not expecting power increase to even be noticeable, but if it is that will be an added bonus.

MrHarris · 03-08-2009, 05:33 PM

Yeah AA X-Pipe/exhaust is the most appealing to me at the moment due to measurable gains and no drone, but man are they expensive!

chris s · 03-08-2009, 06:40 PM

Quote:

Originally Posted by J08M3

AA is real expensive. But I've been researching it lately and they seem to have the best option available. I still don't understand how an x-pipe can be so much? But everyone says their quality is top notch. The fact that it's straight bolt on is nice too. If I end up pulling the trigger on a x-pipe AA is the way I'm gonna go. More for the sound of it combined with HFC and Eisenmann sport than the power increase. Not expecting power increase to even be noticeable, but if it is that will be an added bonus.

What do you plan to do about NYS inspection?

Bx Tpr · 03-08-2009, 06:46 PM

Quote:

Originally Posted by chris s

What do you plan to do about NYS inspection?

As long as he can keep the O2's from setting a code he should be fine. Going catless is where most people without software upgrades are going to have issues getting past inspection in NYS.

J08M3 · 03-08-2009, 07:24 PM

Quote:

Originally Posted by chris s

What do you plan to do about NYS inspection?

I've been in contact with AA trying to figure out if it will pass inspection with HFC's.

My option if it won't is to simply switch back to stock before going for an inspection. Since it's just bolt up switching back to OEM for an inspection is quite easy. But at the same time it would be quite an inconvenience to me. I can jack the car up in my garage and do the work myself. But I am not crazy about having to do this work just to pass. I would like to install my choice of x-pipe and never have to touch it again.

Bx Tpr · 03-08-2009, 07:31 PM

Quote:

Originally Posted by J08M3

I would like to install my choice of x-pipe and never have to touch it again.

Your best bet then would be to retain the stock primary cats and go with like a Supersprint, Fabspeed midpipe section or a custom mid section from an exhaust shop of your choice.

J08M3 · 03-08-2009, 07:37 PM

Quote:

Originally Posted by Bx Tpr

Your best bet then would be to retain the stock primary cats and go with like a Supersprint, Fabspeed midpipe section or a custom mid section from an exhaust shop of your choice.

Unless the HFC will get me by inspection. Eliminating the secondary cat is nice and still having the resonators is too. A HFC, no secondaries, but still resonators should give me the nicest system. That's what I'll have if going with AA. No one seems to have the answer if it will pass inspection yet.

Bx Tpr · 03-08-2009, 07:50 PM

Quote:

Originally Posted by J08M3

Unless the HFC will get me by inspection. Eliminating the secondary cat is nice and still having the resonators is too. A HFC, no secondaries, but still resonators should give me the nicest system. That's what I'll have if going with AA. No one seems to have the answer if it will pass inspection yet.

If you can pass inspection with the HFC's in NYS, the AA mids with HFC's will be my first mod on the car when/if I get it. LoL

Definitely keep us in the loop if you go with the HFC's.

03-08-2009, 05:30 AM	#1
MrHarris yodog 197 Rep 5,026 Posts Drives: '86 Corolla Join Date: Jun 2007 Location: Diamond Bar, Ca iTrader: (5) Garage List 2009 BMW [10.00]	Cat Delete? If I remove the cats on the x-pipe and put straight pipes, would I get similar gains to an aftermarket x-pipe like AA or Encore? __________________ 2009 E92 M3 \| Alpine White \| Black Extended \| Advan RS \| Turner Test Pipes \| Dinan Axle-Back \| OETuning \| Eibach Springs \| UUC SSK \| VRS Front Lip \| VRS Type I Diffuser \| Matte Black \| RPi Scoops \| MS Filter \| Yokohama AD08 \| F1 Pinnacle Special Thanks: Gintani \| OETuning \| eAs
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03-08-2009, 06:53 AM	#2
Sticky Banned 78 Rep 2,244 Posts Drives: E92 Jerez DCT M3 Join Date: Jan 2008 Location: Anaheim Hills / Malibu iTrader: (0)	Similar? Yes...
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03-08-2009, 09:37 AM	#3
J08M3 Major General 285 Rep 6,007 Posts Drives: 2011 M3 COUPE Join Date: May 2008 Location: NEW YORK iTrader: (8)	I think a big part of the reason you see gains with AA x-pipe is because it forces you to get their ECU tune also so it's not just as simple as eliminating a secondary cat. I would expect close to no gain if you only eliminate your secondary cat. Sure it provides some restriction to your system, but it's minimal and will affect sound more than power. __________________
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03-08-2009, 11:34 AM	#4
boostedtwin Sheriff 109 Rep 1,481 Posts Drives: spyder, Macan GTS, 4xe Rubicon Join Date: Mar 2007 Location: Orlando iTrader: (10) Garage List 07 335i [0.00] 07 335i [0.00]	The main restriction are the primary cats... Remove those bad boys and you will notice a difference. AA removes both primary and secondary with X pipe. __________________ 2023 Porsche Spyder, 2024 Porsche Macan GTS, 4Xe Rubicon & 2021 BMW X5 M Package
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03-08-2009, 04:34 PM	#6
J08M3 Major General 285 Rep 6,007 Posts Drives: 2011 M3 COUPE Join Date: May 2008 Location: NEW YORK iTrader: (8)	AA is real expensive. But I've been researching it lately and they seem to have the best option available. I still don't understand how an x-pipe can be so much? But everyone says their quality is top notch. The fact that it's straight bolt on is nice too. If I end up pulling the trigger on a x-pipe AA is the way I'm gonna go. More for the sound of it combined with HFC and Eisenmann sport than the power increase. Not expecting power increase to even be noticeable, but if it is that will be an added bonus. __________________
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03-08-2009, 05:33 PM	#7
MrHarris yodog 197 Rep 5,026 Posts Drives: '86 Corolla Join Date: Jun 2007 Location: Diamond Bar, Ca iTrader: (5) Garage List 2009 BMW [10.00]	Yeah AA X-Pipe/exhaust is the most appealing to me at the moment due to measurable gains and no drone, but man are they expensive! __________________ 2009 E92 M3 \| Alpine White \| Black Extended \| Advan RS \| Turner Test Pipes \| Dinan Axle-Back \| OETuning \| Eibach Springs \| UUC SSK \| VRS Front Lip \| VRS Type I Diffuser \| Matte Black \| RPi Scoops \| MS Filter \| Yokohama AD08 \| F1 Pinnacle Special Thanks: Gintani \| OETuning \| eAs
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