Secondary cat delete with oem exhaust mod?

gatorfast · 07-26-2012, 09:29 AM

Has anyone done this? How do you like the results? How did it change the sound level and character?

I am not looking for any power, just a slight increase in sound.

1sikbmr · 07-26-2012, 10:20 AM

I gutted my oem secondary cats and had the oem exhaust mod. It was barely louder but definitely more deep in sound.

gatorfast · 07-26-2012, 10:23 AM

Interesting. So were you happy with it overall? Is it worth the effort?

gatorfast · 07-27-2012, 10:24 AM

Anyone else have any input?

duke10 · 07-27-2012, 04:27 PM

What kinda exhaust mod? Straight through like ACM or just the regular style? I got straight through with primary cats delete, secondary replaced with HFC and it's LOUD!

gatorfast · 07-27-2012, 06:07 PM

Just the traditional mod (two large perforated pipes covered). I'm def not interested in messing with the primary cats though.

Trevor .:R · 07-28-2012, 04:24 AM

Heres a video of OEM mod with test pipes sounds like the tits! I want to try it,

It is the best sounding ive ever heard... Goodluck on the future decision !

raywong · 07-28-2012, 09:29 AM

Quote:

Originally Posted by duke10

What kinda exhaust mod? Straight through like ACM or just the regular style? I got straight through with primary cats delete, secondary replaced with HFC and it's LOUD!

But the secondary cats and sport cats are both 180 cel!?

gatorfast · 07-28-2012, 10:14 AM

Trevor the car in the vid sounds amazing! However, straight pipes I'm assuming means replacement of primary cats? Def not interested in that. Just want input on deleting secondary cats and keeping primaries and resonators.

blankstar43 · 07-28-2012, 11:23 AM

Just curious, why don't u want to remove or change the primary cats?

gatorfast · 07-28-2012, 06:31 PM

Quote:

Originally Posted by blankstar43

Just curious, why don't u want to remove or change the primary cats?

Many reasons...think it will be too loud, don't want engine light, etc.

Just looking for a little more volume and was hoping a secondary cat delete would do the trick.

gatorfast · 07-28-2012, 08:24 PM

Quote:

Originally Posted by m3alabama

Did you read my post? HFC is quieter than an ACM mod in every way except HFC is much higher pitched and has no drone.

No CEL with active xpipe which I have.

Yes read your post but not sure what it has to do with what I am asking. I have the traditional 2 pipe oem mod, not the acm version. Also HFC = high flow cats correct? As I stated, I am not interested in messing with my primary cats, just looking for input from anyone who has removed secondary cats and what they thought of the results.

meko · 07-28-2012, 10:09 PM

This...I'm in the same boat. I did the 2 pipe mod and LOVE the sound. Now I'm thinking I'd go for little power, and primary cat delete is the only cat you should be deleting for power because secondary flows well already. Leaving the resonator in place to. Too much sound increase and having to get a tune for CEL is what's holding me back. Not sure if it's all worth it honestly. These cars are plenty fast, I just want the S65 to breathe her best. Anyway, you should either do the primary or don't bother IMO.

raywong · 07-28-2012, 11:43 PM

I have a loud car already, the M3 is my daily car so I don't want it too loud, just want to brighten up the tone, and definitely no drone. I already bought the Evolve tune, haven't decided weather to get the HFC or test pipe yet. HFC are expensive but it should sound just right. Test pipe might be smelly and might be a bit too loud for me. Does anyone know how much louder is the test pipe comparing to HFC?

gatorfast · 07-30-2012, 07:53 AM

Quote:

Originally Posted by meko

Anyway, you should either do the primary or don't bother IMO.

What are you basing this on? Have you done this or heard a before/after with secondary cats removed?

meko · 07-30-2012, 10:05 PM

Sorry I didn't explain fully. The second cat flows very well and the big restriction is the primary. My point was about sound and HP. Too much sound in my opinion with little HP increase. If you were going to mess with it, go with primary. It's your car though.

ElmerBento · 07-30-2012, 10:16 PM

It was barely louder but definitely more deep in sound

gatorfast · 07-31-2012, 08:31 AM

Quote:

Originally Posted by ElmerBento

It was barely louder but definitely more deep in sound

Thanks for the input. Im starting to get the impression that it may not be worth the hassle if there is no noticeable increase in sound.

gatorfast · 08-17-2012, 09:53 AM

Debating taking my car in tomorrow to have secondary cats replaced with straight pipes. Anyone else have any input? Will I notice the sound increase or am I wasting my time?

tibra1 · 08-17-2012, 10:37 AM

I wouldnt do it, OEM mod will drone w/ sec cat delete

dtmwerksm3 · 08-17-2012, 04:44 PM

Turner Test Pipes with stock rear section is a great way to fly, not to loud but sounds amazing WOT and on down shifts, combine that with a tune and you're looking at 40+whp/30+wtq gains.

Just did mine the other week

alpina527 · 08-17-2012, 05:03 PM

I've done the secondary cat delete and am happy with the result.

I would say it's got 5-7% more volume, and sounds slightly more aggressive. No Cel issues or drone at all with the oem rear box.

I have tried different setups before which sound great for a Month, but then they would get on my nerves.

The secondary cat delete gives it a subtle improvement and is worth doing. The cats can easily be smashed out from their housings leaving everything looking standard once welded up again.

07-26-2012, 09:29 AM	#1
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Secondary cat delete with oem exhaust mod? Has anyone done this? How do you like the results? How did it change the sound level and character? I am not looking for any power, just a slight increase in sound.
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07-26-2012, 10:20 AM	#2
1sikbmr Brigadier General Drives: E90 M3 6MT Join Date: Mar 2010 Location: New York Posts: 3,106 iTrader: (12)	I gutted my oem secondary cats and had the oem exhaust mod. It was barely louder but definitely more deep in sound. __________________ E90 ///M3 6MT Atlantis Blue - Fox red Gloss black grilles/Red gills\|V1 hardwire\|Painted reflectors\|ZHP lighted shift knob\|VMR V710 silver\|GTS lip\|Lux custom 8k kit\|AA Green Filter\| AA Pulley\| RPI GTM Exhaust\|Sosi x-pipe\|BMW Performance Steering Wheel V1\|

07-28-2012, 04:24 AM	#7
Trevor .:R Captain Drives: 11 ZCP Join Date: Jan 2011 Location: Thousand Oaks/Camarillo/Westlake Posts: 631 iTrader: (1) Garage List 11 M3 [5.00]	Heres a video of OEM mod with test pipes sounds like the tits! I want to try it, It is the best sounding ive ever heard... Goodluck on the future decision ! __________________ 2011 E90 M3 AW COMP

07-28-2012, 11:23 AM	#10
blankstar43 First Lieutenant Drives: 2012 e92 M3 Join Date: Mar 2010 Location: Charleston, SC Posts: 332 iTrader: (1)	Just curious, why don't u want to remove or change the primary cats? __________________ 2012 JZB/Fox Red M3 DCT - Akra slip-on, painted reflectors

07-28-2012, 10:09 PM	#13
meko Private First Class Drives: E92 M3 Join Date: Oct 2010 Location: New Jersey Posts: 109 iTrader: (2)	This...I'm in the same boat. I did the 2 pipe mod and LOVE the sound. Now I'm thinking I'd go for little power, and primary cat delete is the only cat you should be deleting for power because secondary flows well already. Leaving the resonator in place to. Too much sound increase and having to get a tune for CEL is what's holding me back. Not sure if it's all worth it honestly. These cars are plenty fast, I just want the S65 to breathe her best. Anyway, you should either do the primary or don't bother IMO. __________________

07-26-2012, 10:23 AM	#3
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Interesting. So were you happy with it overall? Is it worth the effort?

07-27-2012, 10:24 AM	#4
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Anyone else have any input?

07-27-2012, 04:27 PM	#5
duke10 Private First Class Drives: 2009 BMW e92 M3 Join Date: Jun 2011 Location: Houston, TX Posts: 128 iTrader: (1)	What kinda exhaust mod? Straight through like ACM or just the regular style? I got straight through with primary cats delete, secondary replaced with HFC and it's LOUD!

07-27-2012, 06:07 PM	#6
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Just the traditional mod (two large perforated pipes covered). I'm def not interested in messing with the primary cats though.

07-28-2012, 10:14 AM	#9
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Trevor the car in the vid sounds amazing! However, straight pipes I'm assuming means replacement of primary cats? Def not interested in that. Just want input on deleting secondary cats and keeping primaries and resonators.

07-28-2012, 11:43 PM	#14
raywong Private First Class Drives: E92M3 Join Date: Jun 2011 Location: Hong Kong Posts: 126 iTrader: (0)	I have a loud car already, the M3 is my daily car so I don't want it too loud, just want to brighten up the tone, and definitely no drone. I already bought the Evolve tune, haven't decided weather to get the HFC or test pipe yet. HFC are expensive but it should sound just right. Test pipe might be smelly and might be a bit too loud for me. Does anyone know how much louder is the test pipe comparing to HFC?

07-30-2012, 10:05 PM	#16
meko Private First Class Drives: E92 M3 Join Date: Oct 2010 Location: New Jersey Posts: 109 iTrader: (2)	Sorry I didn't explain fully. The second cat flows very well and the big restriction is the primary. My point was about sound and HP. Too much sound in my opinion with little HP increase. If you were going to mess with it, go with primary. It's your car though. __________________

07-30-2012, 10:16 PM	#17
ElmerBento New Member Drives: bmw Join Date: Jul 2012 Location: nice Posts: 6 iTrader: (0)	It was barely louder but definitely more deep in sound __________________

08-17-2012, 09:53 AM	#19
gatorfast Lieutenant Colonel Drives: MR E90 M3 Join Date: Jan 2008 Location: SoFla Posts: 1,808 iTrader: (3)	Debating taking my car in tomorrow to have secondary cats replaced with straight pipes. Anyone else have any input? Will I notice the sound increase or am I wasting my time?

08-17-2012, 10:37 AM	#20
tibra1 Banned Drives: 2011 ZCP M3 - 2007 335i crashd Join Date: Apr 2009 Location: NYC Posts: 6,779 iTrader: (4)	I wouldnt do it, OEM mod will drone w/ sec cat delete

08-17-2012, 04:44 PM	#21
dtmwerksm3 Second Lieutenant Drives: 09 M3 DCT Alpine White/Fox Red Join Date: Oct 2011 Location: San Diego, CA Posts: 223 iTrader: (0)	Turner Test Pipes with stock rear section is a great way to fly, not to loud but sounds amazing WOT and on down shifts, combine that with a tune and you're looking at 40+whp/30+wtq gains. Just did mine the other week __________________ 2012 BMW S1000RR — Racing Red/Alpine White 2009 BMW M3 Coupe — Alpine White on Fox Red, DCT - ESS \| Turner Test Pipes \| Macht Schnell Stg 2 \| OEM Performance Splitters, Spoiler & Mirror Caps \| 3D Design Diffuser 2003 BMW M3 — Carbon Black on Black, 6MT - DPE \| B&G \| K&N \| JL AUDIO - Sold 1995 BMW M3 Coupe — Cosmos Black on Black - Sold

08-17-2012, 05:03 PM	#22
alpina527 Captain Drives: 2008 E92 M3 DCT JZB/FR Join Date: Jan 2010 Location: London, England Posts: 627 iTrader: (1)	I've done the secondary cat delete and am happy with the result. I would say it's got 5-7% more volume, and sounds slightly more aggressive. No Cel issues or drone at all with the oem rear box. I have tried different setups before which sound great for a Month, but then they would get on my nerves. The secondary cat delete gives it a subtle improvement and is worth doing. The cats can easily be smashed out from their housings leaving everything looking standard once welded up again.

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