exhaust on 2.2 turbo, remove cat?

southernrock20 · 07-08-2009, 07:58 AM

im getting my exhaust done ( 3 inch from the turbo to the tail) and was wandering if removing the cat is a good idea? I have heard conflicting stories that it will help, but on earlier model cars it will actually hurt performance. I will also be getting my truck tuned soon after.

Lifted97s-10 · 07-08-2009, 09:33 AM

To be honest it won't give you any noticeable power gain. But it you want to get something more free flowing just get a magnaflow fi-flow cat.

~~4x4zr2GA~~ · 07-09-2009, 01:44 AM

turbo acts as the restriction for the exhuast sytem... with a turbo, you want the exhuast to be as least restrictive as possible since the turbo itself puts restriction on it. remove it, you certainly dont need it for inspection since you live in alabama, and c'mon... its turbocharged, wtf would you need a cat. for?

southernrock20 · 07-09-2009, 07:27 AM

well, i have just read and heard that removing the cat in some vehicles would actually cause more problems than good, but i will let the exhaust place know. thanks guys

Gutling · 07-09-2009, 08:32 AM

Mines been off since the day i bought it. it effects nothing.

tiresmokinV8 · 07-09-2009, 03:42 PM

Yea If you dont need it in your area for emissions, take it off, Turboes dont like any restrictions past them.

southernrock20 · 07-09-2009, 04:27 PM

i just cranked it up today, for the first time in a while to go to the exhaust place, well now i have bigger issues with that stupid snow kit leaking like crazy, and i drove over 30 min to that exhaust place just for him not to give me an estimate and say come back around the 20th since hell be on vacation....but ill go ahead and get the cat removed and get a high flow muffler, is there one that sounds like the turbo muffler? i love the way it kinda crackels when you let off the gas

Lifted97s-10 · 07-09-2009, 06:36 PM

Spintech Prostreet

KJF95S-10 · 07-09-2009, 08:08 PM

Yea cats are total BS on any turbo engine. You should notice a decent performance gain by removing it.

tiresmokinV8 · 07-09-2009, 11:58 PM

Get a decent straight throw muffler like magnaflow.

Gutling · 07-10-2009, 08:52 PM

Almost any muffler is going to crackle when the cat is removed. I have a magnaflow on mine, and it sounds awesome even without the turbo.

~~SteveHH~~ · 07-10-2009, 09:03 PM

lawnmower

southernrock20 · 07-11-2009, 12:23 PM

Quote: Originally Posted by Dr. Steve

lawnmower

lol, i hope not

King_Ice_Flash2 · 07-12-2009, 10:39 AM

Quote: Originally Posted by KJF95S-10

Yea cats are total BS on any turbo engine. You should notice a decent performance gain by removing it.

The change on mine was NOT noticeable.

southernrock20 · 07-13-2009, 05:33 PM

well, i got back from the exhaust place, i got 2 1/2 from the cat back. ( i think from the turbo to the cat is 2 1/2 and the cat is 2 1/4) they wouldnt cut it off, even if i cut it off they wouldnt mess with it. I also changed from a turbo muffler to the flowmaster. It sounds alot quieter than the turbo. I like it. The performance is great, but then again i had a major leak at the header. So that contributes to alot of the gains. Also got 2 1/2 SS tips. all and all it was nearly 400 bucks. I guess thats good.

A CLEANMACHINE · 07-18-2009, 09:08 PM

Quote: Originally Posted by southernrock20

well, i got back from the exhaust place, i got 2 1/2 from the cat back. ( i think from the turbo to the cat is 2 1/2 and the cat is 2 1/4) they wouldnt cut it off, even if i cut it off they wouldnt mess with it. I also changed from a turbo muffler to the flowmaster. It sounds alot quieter than the turbo. I like it. The performance is great, but then again i had a major leak at the header. So that contributes to alot of the gains. Also got 2 1/2 SS tips. all and all it was nearly 400 bucks. I guess thats good.

read this

Exhaust System

The goal of a good exhaust system is to minimize back pressure. Back pressure prevents the turbocharger from spooling up freely creating lag and a loss of power. The key to minimizing back pressure is to use straight through mufflers, mandrel bent piping, and larger than stock diameter pipe. The turbocharger itself acts as a good muffler, removing as much as 1/3 of the noise from the exhaust system. The first component that requires consideration are the mufflers. Mufflers that have a straight through design do not have internal baffles. The ideal straight through design will have a perforated core instead of a louvered one. Louvers protrude into the exhaust flow to muffle the noise. Perforated cores have holes in the center pipe that do not inhibit exhaust flow. Another thing to look for in a good muffler is stainless steel packing. Stainless packing will not burn out of the muffler like fiberglass (which is used in most aftermarket mufflers) will. MagnaFlow makes excellent universal mufflers that meet these requirements. Of course the best muffler in the world will not make any difference if the pipe diameter is small, restricting gas flow. Two factors effect exhaust flow, the type of bend used and the diameter of the pipe. Two types of pipe bend are crush and mandrel. Crush bending works by crushing the pipe at the bend, in effect, putting a kink in the pipe, reducing the diameter of the pipe at that bend. Mandrel bending works by stretching the pipe as it is bent. The result is a bend that does not reduce the diameter of the pipe. As far as diameter goes, bigger is better, but up to a point. The Corkey Bell book "Maximum Boost: Design, Testing, and Installing Turbocharger Systems" suggests that the full benefits of 3" diameter pipe will not be fully realized until 700 horsepower! To learn more about why, pick up the book. Clearance with the rear suspension can also be an issue with 3" pipe, especially if the car is lowered. If you choose to have a custom exhaust system made and crush bending is the only option (mandrel bending machines are expensive so a lot of shops do not have them) then 3" would be the way to go. The extra diameter will compensate for the diameter you lose when crush bending. If you have access to mandrel bending services then 2.5" diameter pipe is ideal to use. The 2.5" pipe is good to 500 horsepower. The only option for a prefabricated, bolt-on, exhaust system that is suitable for use on a turbocharged car is from Thermal Research & Development
The catalytic converter is a significant flow restricter in the exhaust system, even presumably 'high flow' cats. You can expect as much as a 30 horsepower gain by removing the cat. Having the cat in the system will also contribute to extremely sluggish low RPM performance. However, removing the cat in most areas of the country is illegal and results in a heavy fine, remove it at your own risk. One option to reduce the chance of being caught it to have a fake heat shield that looks like a cat's heat shield welded onto a straight pipe, making it look like a cat (I'm not telling you to do this, I'm just telling you what some people have done).

southernrock20 · 07-18-2009, 10:23 PM

ive always thought that when they bent the exhaust, that your not really getting the full 2 1/2 and since my cat is still 2 1/4 i didnt figure that getting 2 1/2 past that would make any difference lol.But im still working on trying to get the cat off but i so far i cant find a place to put in a 2 1/2 pipe for me. I can cut the cat off myself, but no one will put in a straight pipe for me. They say since they know of what vehicles came with cats, they wont mess with it. sucks for me i guess lol.

07-08-2009, 07:58 AM	#1
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	exhaust on 2.2 turbo, remove cat? im getting my exhaust done ( 3 inch from the turbo to the tail) and was wandering if removing the cat is a good idea? I have heard conflicting stories that it will help, but on earlier model cars it will actually hurt performance. I will also be getting my truck tuned soon after.
	[Reply w/Quote]

07-08-2009, 09:33 AM	#2
Lifted97s-10 V8.cuz.big.girls.cant.run Age: 23 Join Date: Jun 2008 Posts: 1,235 Location: Stow User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? To be honest it won't give you any noticeable power gain. But it you want to get something more free flowing just get a magnaflow fi-flow cat.
	[Reply w/Quote]

07-09-2009, 01:44 AM	#3
~~4x4zr2GA~~ Banned Age: 26 Join Date: Feb 2006 Posts: 2,361 Location: warner robins, GA User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? turbo acts as the restriction for the exhuast sytem... with a turbo, you want the exhuast to be as least restrictive as possible since the turbo itself puts restriction on it. remove it, you certainly dont need it for inspection since you live in alabama, and c'mon... its turbocharged, wtf would you need a cat. for?
	[Reply w/Quote]

07-09-2009, 07:27 AM	#4
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? well, i have just read and heard that removing the cat in some vehicles would actually cause more problems than good, but i will let the exhaust place know. thanks guys
	[Reply w/Quote]

07-09-2009, 08:32 AM	#5
Gutling Registered User Age: 30 Join Date: Mar 2007 Posts: 911 Location: Claxton, GA User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Mines been off since the day i bought it. it effects nothing.
	[Reply w/Quote]

07-09-2009, 03:42 PM	#6
tiresmokinV8 Drives a VVT LSX Sonoma.. Age: 27 Join Date: Nov 2007 Posts: 3,194 Location: Springfield Twp, Ohio User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Yea If you dont need it in your area for emissions, take it off, Turboes dont like any restrictions past them.
	[Reply w/Quote]

07-09-2009, 04:27 PM	#7
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? i just cranked it up today, for the first time in a while to go to the exhaust place, well now i have bigger issues with that stupid snow kit leaking like crazy, and i drove over 30 min to that exhaust place just for him not to give me an estimate and say come back around the 20th since hell be on vacation....but ill go ahead and get the cat removed and get a high flow muffler, is there one that sounds like the turbo muffler? i love the way it kinda crackels when you let off the gas
	[Reply w/Quote]

07-09-2009, 06:36 PM	#8
Lifted97s-10 V8.cuz.big.girls.cant.run Age: 23 Join Date: Jun 2008 Posts: 1,235 Location: Stow User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Spintech Prostreet
	[Reply w/Quote]

07-09-2009, 08:08 PM	#9
KJF95S-10 Two tones of terror Age: 23 Join Date: Feb 2008 Posts: 675 Location: Tampa, FL User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Yea cats are total BS on any turbo engine. You should notice a decent performance gain by removing it.
	[Reply w/Quote]

07-09-2009, 11:58 PM	#10
tiresmokinV8 Drives a VVT LSX Sonoma.. Age: 27 Join Date: Nov 2007 Posts: 3,194 Location: Springfield Twp, Ohio User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Get a decent straight throw muffler like magnaflow.
	[Reply w/Quote]

07-10-2009, 08:52 PM	#11
Gutling Registered User Age: 30 Join Date: Mar 2007 Posts: 911 Location: Claxton, GA User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Almost any muffler is going to crackle when the cat is removed. I have a magnaflow on mine, and it sounds awesome even without the turbo.
	[Reply w/Quote]

07-10-2009, 09:03 PM	#12
~~SteveHH~~ Banned Age: 30 Join Date: May 2006 Posts: 12,194 Location: Levittown, PA-☆-NE Philly-☆-Trenton, NJ-☆Tha 19057 Bitches☆ User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? lawnmower
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07-11-2009, 12:23 PM	#13
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Quote: Originally Posted by Dr. Steve lawnmower lol, i hope not
	[Reply w/Quote]

07-12-2009, 10:39 AM	#14
King_Ice_Flash2 Will work for turbo parts Join Date: Jan 2007 Posts: 2,789 Location: SE, WI User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Quote: Originally Posted by KJF95S-10 Yea cats are total BS on any turbo engine. You should notice a decent performance gain by removing it. The change on mine was NOT noticeable.
	[Reply w/Quote]

07-13-2009, 05:33 PM	#15
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? well, i got back from the exhaust place, i got 2 1/2 from the cat back. ( i think from the turbo to the cat is 2 1/2 and the cat is 2 1/4) they wouldnt cut it off, even if i cut it off they wouldnt mess with it. I also changed from a turbo muffler to the flowmaster. It sounds alot quieter than the turbo. I like it. The performance is great, but then again i had a major leak at the header. So that contributes to alot of the gains. Also got 2 1/2 SS tips. all and all it was nearly 400 bucks. I guess thats good.
	[Reply w/Quote]

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07-18-2009, 09:08 PM	#16
A CLEANMACHINE Registered User Join Date: Sep 2006 Posts: 1,070 Location: ORLAND PARK ILLINOIS User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? Quote: Originally Posted by southernrock20 well, i got back from the exhaust place, i got 2 1/2 from the cat back. ( i think from the turbo to the cat is 2 1/2 and the cat is 2 1/4) they wouldnt cut it off, even if i cut it off they wouldnt mess with it. I also changed from a turbo muffler to the flowmaster. It sounds alot quieter than the turbo. I like it. The performance is great, but then again i had a major leak at the header. So that contributes to alot of the gains. Also got 2 1/2 SS tips. all and all it was nearly 400 bucks. I guess thats good. read this Exhaust System The goal of a good exhaust system is to minimize back pressure. Back pressure prevents the turbocharger from spooling up freely creating lag and a loss of power. The key to minimizing back pressure is to use straight through mufflers, mandrel bent piping, and larger than stock diameter pipe. The turbocharger itself acts as a good muffler, removing as much as 1/3 of the noise from the exhaust system. The first component that requires consideration are the mufflers. Mufflers that have a straight through design do not have internal baffles. The ideal straight through design will have a perforated core instead of a louvered one. Louvers protrude into the exhaust flow to muffle the noise. Perforated cores have holes in the center pipe that do not inhibit exhaust flow. Another thing to look for in a good muffler is stainless steel packing. Stainless packing will not burn out of the muffler like fiberglass (which is used in most aftermarket mufflers) will. MagnaFlow makes excellent universal mufflers that meet these requirements. Of course the best muffler in the world will not make any difference if the pipe diameter is small, restricting gas flow. Two factors effect exhaust flow, the type of bend used and the diameter of the pipe. Two types of pipe bend are crush and mandrel. Crush bending works by crushing the pipe at the bend, in effect, putting a kink in the pipe, reducing the diameter of the pipe at that bend. Mandrel bending works by stretching the pipe as it is bent. The result is a bend that does not reduce the diameter of the pipe. As far as diameter goes, bigger is better, but up to a point. The Corkey Bell book "Maximum Boost: Design, Testing, and Installing Turbocharger Systems" suggests that the full benefits of 3" diameter pipe will not be fully realized until 700 horsepower! To learn more about why, pick up the book. Clearance with the rear suspension can also be an issue with 3" pipe, especially if the car is lowered. If you choose to have a custom exhaust system made and crush bending is the only option (mandrel bending machines are expensive so a lot of shops do not have them) then 3" would be the way to go. The extra diameter will compensate for the diameter you lose when crush bending. If you have access to mandrel bending services then 2.5" diameter pipe is ideal to use. The 2.5" pipe is good to 500 horsepower. The only option for a prefabricated, bolt-on, exhaust system that is suitable for use on a turbocharged car is from Thermal Research & Development The catalytic converter is a significant flow restricter in the exhaust system, even presumably 'high flow' cats. You can expect as much as a 30 horsepower gain by removing the cat. Having the cat in the system will also contribute to extremely sluggish low RPM performance. However, removing the cat in most areas of the country is illegal and results in a heavy fine, remove it at your own risk. One option to reduce the chance of being caught it to have a fake heat shield that looks like a cat's heat shield welded onto a straight pipe, making it look like a cat (I'm not telling you to do this, I'm just telling you what some people have done).
	[Reply w/Quote]

07-18-2009, 10:23 PM	#17
southernrock20 one of a kind Age: 27 Join Date: Feb 2007 Posts: 1,962 Location: SA TX User is: OffLine	Re: exhaust on 2.2 turbo, remove cat? ive always thought that when they bent the exhaust, that your not really getting the full 2 1/2 and since my cat is still 2 1/4 i didnt figure that getting 2 1/2 past that would make any difference lol.But im still working on trying to get the cat off but i so far i cant find a place to put in a 2 1/2 pipe for me. I can cut the cat off myself, but no one will put in a straight pipe for me. They say since they know of what vehicles came with cats, they wont mess with it. sucks for me i guess lol.
	[Reply w/Quote]