Can/should I rip out my catalytic?
09-08-2006, 08:23 PM
#16
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Originally Posted by Imo000
That may be in a N/A application, but it makes a HUGE difference when boosted. I’ve removed mine and replaced it with only an H- pipe and the engine woke up. My guess is at least a 25hp gain from removing the original cats. A boosted engine loves free flowing exhaust. The freer the better.
On a N/A car I wouldn’t remove them. If they are plugged, replace it cause as mentioned above the gain is hardly noticeable but the smell sure isn’t.
On a N/A car I wouldn’t remove them. If they are plugged, replace it cause as mentioned above the gain is hardly noticeable but the smell sure isn’t.
-Cat's are "scrubbers", designed to remove the garbage when the engine misbehaves and produces too many noxious emissions. Here's the thing most people don't understand: a properly functioning fuel injection system does not put any load on the cats....at least in the research I've done. That's why a bunch of 928 people out in the People's Republic of California have PASSED emissions testing when they have arrived at the testing station with catalytic converters that are basically hollow metal tubes. If your engine runs right, you don't need the damn thing.
NOW- do this: Do a Rennlist search regarding "fuel injection problems" on the 928 forums and tell me how many pages you come up with. Certainly in the 100's....
Hello?
Cat's on a fairly new ZO6 are probably overkill. On a 20+ year old 928? Probably a good idea, especially when products that will not cost you a single horsepower up to 500 hp level are available!
::slides a beer down the bar anyway::N!
09-08-2006, 10:13 PM
#17
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Originally Posted by MGW-Fla
yeah I say DITCH THE CATS!!!! I love the environment as much as most people, but common now..... there are much bigger problems than her 928 without the cats. Lord, just this week alone in traffic I've seen several cars pouring out so much smoke you'd think they were on fire! You see them on a regular basis here. If those can slide without recourse, then the system is just messed up. You will notice more low end torque, a more robust exhaust note, and perhaps a bit of gas/exhaust smell upon start up or shut down, but not enough to deter from the added benefits in my book. Again I say, DITCH THE CATS & GET AN XPIPE!
09-09-2006, 01:14 AM
#18
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If you get caught with no cats on a vehicle that orginal was equipped with cats. $1500.00 fine. Federal law under the EPA Clean Air Act.
Here in NJ spot road side inspections are common.
Install an X pipe and use 2 cats for free exahust flow. Good for 25 HP+
Here in NJ spot road side inspections are common.
Install an X pipe and use 2 cats for free exahust flow. Good for 25 HP+
09-09-2006, 10:36 AM
#20
Instructor
Originally Posted by dr bob
It's hard to believe that NY doesn't care about cars over ten years old.
These motor vehicles are exempt from emissions inspection for gas-powered vehicles:
Vehicles that are less than two model years old, or more than 25 model years old (for example, a 1975 model in 2001).
What emissions inspection is required if a gas-powered vehicle is not required to have the OBDII test and is not exempt from emissions inspection?
If a vehicle is a 1995 or older model gas-powered vehicle that is not exempt from emissions inspection the vehicle receives:
A high-enhanced emissions inspection if the vehicle is registered in the NYCMA, or
A low-enhanced emissions inspection if the vehicle is registered in the Upstate Area.
THE LOW-ENHANCED EMISSIONS INSPECTION FOR THE UPSTATE AREA
A 1995 or older model year vehicle, or a vehicle that weighs 8,501 lbs. or more is required to have a low-enhanced emissions inspection if the vehicle:
Is registered in the Upstate Area, and
Is not exempt from emissions inspection.
What does the low-enhanced emissions inspection include?
The low-enhanced emissions inspection includes a gas cap check and a visual inspection to find evidence of tampering and to prevent malfunctions in the air pollution control devices. The test is done annually at the same time as the safety inspection.
Bottom Line: Your car is less than 25 years old -- You definitely need a low-enhanced emissions inspection with a visual check of the pollution control devices -- You need a cat...
Originally Posted by Sexy928Porsche
Seems that my cat is causing problems...NYS states that emissions control systems on gas-powered vehicles that have a model year of 1996 and newer have to pass. Nothing about prior to 1996.
New York State has a new program for annual vehicle inspection (NYVIP).
The NYVIP is a program that includes a new inspection of the emissions control systems on gas-powered vehicles that have a model year of 1996 and newer. The NYVIP inspection also includes:
The current safety inspection,
The current gas cap check, and
The current visual inspection of the emission control devices.
The NYVIP will help NYS to comply with the Federal Clean Air Act, decrease the emissions from motor vehicles, and reduce air pollution.
Below are FAQs about the NYVIP inspection:
When will the NYVIP begin?
NYCMA: The NYCMA includes nine counties: the five boroughs of New York City, Nassau county, Suffolk County, Westchester County, and Rockland County. All NYS-licensed inspection stations must begin the new program no later than April 1, 2005.
Upstate Area: The Upstate Area includes the 53 counties in New York State that are located north of the NYCMA. The NYVIP began in the Upstate Area in September of 2004.
09-09-2006, 03:38 PM
#21
Drifting
As far as cats go, we verified a loss of 14 hp using the standard available Gorlich, dynomax, etc. 400cpi (cell per inch) ceramic cats on our X-over. We switched to a 300cpi metal matrix spiral wound cat and saw losses of 7 to 8 hp. I have since had a custom batch of 500, 100cpi metal matrix spiral wound cats made that show almost no loss. They are not as efficient (clean) as the 300cpi, but they are more than enough on any well running 32 valve engine. The 300cpi cats were tested against the factory 3 stage air injected cats and were almost exactly the same emission wise.
Technology has come a long ways in catalytic converters. The 100cpi cats I had made will offer almost no flow restriction while still cleaning the exhaust up more than enough for even the most stringent emission tests. We sell them for $299.95 a pair if you purchase a X-over or $159.95 each in 100cpi or 300cpi and 2.5" or 3" configurations.
And Rhys...we do strive to be clean but if you want to be the cleanest...don't drive at all.
Technology has come a long ways in catalytic converters. The 100cpi cats I had made will offer almost no flow restriction while still cleaning the exhaust up more than enough for even the most stringent emission tests. We sell them for $299.95 a pair if you purchase a X-over or $159.95 each in 100cpi or 300cpi and 2.5" or 3" configurations.
And Rhys...we do strive to be clean but if you want to be the cleanest...don't drive at all.
Last edited by Ketchmi; 10-25-2007 at 04:57 PM.
09-09-2006, 07:28 PM
#23
Drifting
Yes we can, you just have to cut the last 9" off of the pipes, slip these on and install the clamps. (included with the cats) The cut off parts can easily be swaged to fit over the rear of the X-over to run catless once again. They do a significant amout of noise reduction also...
09-09-2006, 09:20 PM
#24
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Originally Posted by Ketchmi
Yes we can, you just have to cut the last 9" off of the pipes, slip these on and install the clamps. (included with the cats) The cut off parts can easily be swaged to fit over the rear of the X-over to run catless once again. They do a significant amout of noise reduction also...
09-09-2006, 09:38 PM
#25
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My noise level picked up incredibly when I removed the cats. Prior, the car just had a growl. I suspect it had something to do with the "sewer pipe" exhaust. I make a note of crawling through my neighborhood in my 928S2 at idle in 5th gear- S2's do this, other cars don't!
S2's are rarely bothered by bridges here in south Florida!
S2's are rarely bothered by bridges here in south Florida!
