seconadary cats question

bmwm3redblack · 06-29-2013, 01:19 PM

Hey guys. I wnat to be fbo next month, the only problem is i'm not going to buy catback, and don't know what to do with sec cats?

If i delete them, will i get more power? Sound? Or i should leave it and just go with catless dp's?

WesleyC · 06-29-2013, 01:21 PM

Leave them.

135Pats · 06-29-2013, 01:54 PM

At FBO power theyre probably costing you a few whp, debatable as to whether youd notice it.

bmwm3redblack · 06-29-2013, 01:56 PM

Quote:

Originally Posted by 135Pats

At FBO power theyre probably costing you a few whp, debatable as to whether youd notice it.

Any louder sound???

E90Company · 06-29-2013, 02:14 PM

Quote:

Originally Posted by bmwm3redblack

Any louder sound???

Raspier. If you like fart can sounds do it.

bmwm3redblack · 06-29-2013, 02:21 PM

Quote:

Originally Posted by E90Company

Raspier. If you like fart can sounds do it.

So it's useless mod

Blaster400 · 06-29-2013, 02:47 PM

You open yourself up to smoking and smell issues if you remove secondary cats with catless DP. Leave them in.

E90Company · 06-29-2013, 04:01 PM

Quote:

Originally Posted by bmwm3redblack

So it's useless mod

What's the problem? You arn't happy with your exhaust sound? Going off your sig you don't have downpipes, get those first and then see if you need more. Do you have an E90 or E92.

R.G. · 06-29-2013, 04:16 PM

Quote:

Originally Posted by Blaster400

You open yourself up to smoking and smell issues if you remove secondary cats with catless DP. Leave them in.

+1

Maxspeed · 06-29-2013, 06:17 PM

I'm fully catless and I don't like the smell. Definitely keep the secondaries!

bmwm3redblack · 06-30-2013, 08:57 AM

Quote:

Originally Posted by E90Company

What's the problem? You arn't happy with your exhaust sound? Going off your sig you don't have downpipes, get those first and then see if you need more. Do you have an E90 or E92.

I'm e92 and i'm waiting my catless dp's in 2 weeks.
Does catless dp's dramatically improve exhaust sound? cause the sound clips in youtube seems it si not?

Blaster400 · 06-30-2013, 09:11 AM

Quote:

Originally Posted by bmwm3redblack

I'm e92 and i'm waiting my catless dp's in 2 weeks.
Does catless dp's dramatically improve exhaust sound? cause the sound clips in youtube seems it si not?

You will notice a very nice difference in sound when you add downpipes. I'm E92 also with catless DP and stock exhaust including secondary cats plus golf tee mod. Everyone has different taste in exhaust sound but to me the sound is perfect. And YouTube clips are not the best way to evaluate exhaust sound.

Wedge1967 · 06-30-2013, 09:47 AM

Quote:

Originally Posted by 135Pats

At FBO power theyre probably costing you a few whp, debatable as to whether youd notice it.

I would normally agree with your assumption, but I removed mine for shift sector and honestly I didn't see an increase on the dyno after removing them. If anything it killed the sound of my exhaust and my car smoked really bad after removing them. I have new turbos now, but honestly I would never run without the secondaries ever again after my experience.

E90Company · 06-30-2013, 10:07 AM

Quote:

Originally Posted by bmwm3redblack

I'm e92 and i'm waiting my catless dp's in 2 weeks.
Does catless dp's dramatically improve exhaust sound? cause the sound clips in youtube seems it si not?

I would say wait until you get the downpipes and go from there. If you want something else, look into mufflers.

Quote:

Originally Posted by Wedge1967

I would normally agree with your assumption, but I removed mine for shift sector and honestly I didn't see an increase on the dyno after removing them. If anything it killed the sound of my exhaust and my car smoked really bad after removing them. I have new turbos now, but honestly I would never run without the secondaries ever again after my experience.

+1. The cons outweigh the possible benefits on stock turbos.

bmwm3redblack · 06-30-2013, 10:39 AM

Quote:

Originally Posted by Blaster400

You will notice a very nice difference in sound when you add downpipes. I'm E92 also with catless DP and stock exhaust including secondary cats plus golf tee mod. Everyone has different taste in exhaust sound but to me the sound is perfect. And YouTube clips are not the best way to evaluate exhaust sound.

I don't wanna a screaming and raspy sound. Just louder than mine stock unit, if dp's male it louder i'll be happy!!!

E90Company · 06-30-2013, 11:48 AM

Quote:

Originally Posted by bmwm3redblack

I don't wanna a screaming and raspy sound. Just louder than mine stock unit, if dp's male it louder i'll be happy!!!

You will probably be happy with downpipes then.

07tundra · 06-30-2013, 02:53 PM

I got rid of mine and yes smell is horrible! I instead went with 200cell race cats very flowing and no smell. I do get some rasp but I have a muffler delete also.

robc1976 · 06-30-2013, 03:38 PM

Put vibrant 1792 resonators in place of cats and the "ultra quite" resonators in place of mufflers. It is a perfect sound...no rasp and 0 drone. I love it.

07tundra · 06-30-2013, 03:50 PM

Quote:

Originally Posted by robc1976

Put vibrant 1792 resonators in place of cats and the "ultra quite" resonators in place of mufflers. It is a perfect sound...no rasp and 0 drone. I love it.

You're sold on it Rob that's good you found a combo you like!......I will be doing something similar when I get home!

robc1976 · 06-30-2013, 03:58 PM

Quote:

Originally Posted by 07tundra

You're sold on it Rob that's good you found a combo you like!......I will doing something similar when I get home!

Only thing I am changing and is the getting stainless piping...instead of getting expensive Meisterschaft piping I am considering getting the M2 exhaust...cutting out the mufflers and replacing with "ultra quite" resonators. Basically just use the piping. I need to know if that system has resonators or not and if so what kind.

07tundra · 06-30-2013, 04:03 PM

Quote:

Originally Posted by robc1976

Only thing I am changing and is the getting stainless piping...instead of getting expensive Meisterschaft piping I am considering getting the M2 exhaust...cutting out the mufflers and replacing with "ultra quite" resonators. Basically just use the piping. I need to know if that system has resonators or not and if so what kind.

Hey that's a smart idea.....i think it does have some bullet style resonators!

boris · 06-30-2013, 04:09 PM

How else are people going to see your flames?

See if theres a local in your area running a catless tbe.

my money's on you'll think it sounds idiotic.

06-29-2013, 01:19 PM	#1
bmwm3redblack Captain 59 Rep 886 Posts Drives: BMW ///M3 E46, BMW E92 335Xi Join Date: Jan 2011 Location: e13 osl iTrader: (0)	seconadary cats question Hey guys. I wnat to be fbo next month, the only problem is i'm not going to buy catback, and don't know what to do with sec cats? If i delete them, will i get more power? Sound? Or i should leave it and just go with catless dp's? __________________ Bmw 335xi/FBO/ black on black/ 6sp manual/Cobb AP/BMS DCI/AA BOV KIT/VRSF DP'S/VRSF 7'FMIC /FULLY CATLESS/H&R sport springs/ 19' ac schnitzer wheels.
	Appreciate 0 Tweet Quote

06-29-2013, 01:21 PM	#2
WesleyC Colonel 54 Rep 2,907 Posts Drives: BMW Join Date: Dec 2008 iTrader: (20)	Leave them.
	Appreciate 0 Quote

06-29-2013, 01:54 PM	#3
135Pats Major General 456 Rep 6,478 Posts Drives: A few BMWs Join Date: May 2012 Location: Maryland iTrader: (3)	At FBO power theyre probably costing you a few whp, debatable as to whether youd notice it.
	Appreciate 0 Quote

06-29-2013, 02:47 PM	#7
Blaster400 Captain 127 Rep 865 Posts Drives: BMW X3 35i, Porsche Macan S Join Date: Jul 2012 Location: Scottsdale AZ iTrader: (3) Garage List 2018 Porsche Macan S [0.00] 2012 BMW X3 35i [0.00]	You open yourself up to smoking and smell issues if you remove secondary cats with catless DP. Leave them in. __________________ MOTIV 750 ST \| MOTIV PI \| 100% E85 \| Fuel-it Stage 4 LPFP \| MOTIV Boost Box + MHD Protune \| Quaife \| Öhlins \| Brembo \| Akrapovic
	Appreciate 0 Quote

06-29-2013, 06:17 PM	#10
Maxspeed Private First Class 9 Rep 115 Posts Drives: 2009 BMW 335i Coupe Join Date: Apr 2013 Location: CA iTrader: (0)	I'm fully catless and I don't like the smell. Definitely keep the secondaries!
	Appreciate 0 Quote

06-30-2013, 02:53 PM	#17
07tundra Lieutenant Colonel 119 Rep 1,525 Posts Drives: 8.1L Chevy 2500hd Join Date: Jan 2012 Location: New Mexico iTrader: (9)	Cats I got rid of mine and yes smell is horrible! I instead went with 200cell race cats very flowing and no smell. I do get some rasp but I have a muffler delete also.
	Appreciate 0 Quote

06-30-2013, 03:38 PM	#18
robc1976 DIYER 614 Rep 5,521 Posts Drives: E90 335i Join Date: Mar 2012 Location: Illinois iTrader: (14)	Put vibrant 1792 resonators in place of cats and the "ultra quite" resonators in place of mufflers. It is a perfect sound...no rasp and 0 drone. I love it.
	Appreciate 0 Quote

06-30-2013, 04:09 PM	#22
boris Борис 31 Rep 505 Posts Drives: e92 n54 335i Join Date: Nov 2012 Location: CT iTrader: (1)	How else are people going to see your flames? See if theres a local in your area running a catless tbe. my money's on you'll think it sounds idiotic. __________________ 07 SG 335i GONE! COBB - Burger Motorsports -Ultimate Racing - Evolution Racewerks - TiAL- AMS In Winter Mode - Dunlop Wintersport 3D/Sport Edition Wheels
	Appreciate 0 Quote