100 Cell Hi Flo cats?
02-17-2012 | 01:30 PM
#16
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Cats dont really cause much power loss (especially the newer high flow cats). The sound is not that muffled either. Is the gain of 2-3 HP really worth smelling like hydrocarbons. I've never owned a 928 without CATs, but other V8s and my Rx7 without cats will make your eyes water just standing near the car.
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
I either do with cats now and not do the MM / OPG, or do the MM / OPG and a straight x-pipe and put the cats on later.
Keeping in mind the car is not driven much and I would not DD a car with no cats. But I would kick myself if I got caught during the pre-cat period.
02-17-2012 | 01:44 PM
#17
Racer
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From: Stoney Creek, Ont
mine is an 89 so it's a moot point. I need cats to pass smog every 2 years. The only question for me is whether I buy the cats from Roger or try to source something locally and not incur the shipping costs. Are the ones that Roger sells a common name brand that we could find up here?
02-17-2012 | 02:01 PM
#18
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mine is an 89 so it's a moot point. I need cats to pass smog every 2 years. The only question for me is whether I buy the cats from Roger or try to source something locally and not incur the shipping costs. Are the ones that Roger sells a common name brand that we could find up here?
02-17-2012 | 02:03 PM
#20
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From: Bird lover in Sharpsburg
Cats dont really cause much power loss (especially the newer high flow cats). The sound is not that muffled either. Is the gain of 2-3 HP really worth smelling like hydrocarbons. I've never owned a 928 without CATs, but other V8s and my Rx7 without cats will make your eyes water just standing near the car.
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
02-17-2012 | 02:10 PM
#21
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The RX-7 will, I have had several FB's, the old rotaries had an after burner chamber and 3 cats to burn that unused fuel. My last GSL-SE gave me headaches, header and Racing beat no cat exhaust.
02-17-2012 | 02:12 PM
#22
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Cats dont really cause much power loss (especially the newer high flow cats). The sound is not that muffled either. Is the gain of 2-3 HP really worth smelling like hydrocarbons. I've never owned a 928 without CATs, but other V8s and my Rx7 without cats will make your eyes water just standing near the car.
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
IMHO (since you asked) its seriously irresponsible to drive around without Cat Converters, especially if you consider why they were actually required on cars in the first place. In America, there are huge fines if you are caught operating a cat-less car on public roads, including impounding of the vehicle and complex hurdles to it back. (if the car was originally equipped with one). I'm not sure if you realize the gains of running with no cats are very minimal compared to replacing the factory unit, especially if you have a car that has been running rich or misfiring (not igniting). Even in boosted applications the gains only really show up at higher RPM's.
Here are some facts to help my make an informed decision .
http://www.importtuner.com/features/...l/viewall.html
http://www.epa.gov/compliance/resour...hsysrepair.pdf
I agree with Greg, if it stinks too much the engine is too rich. Mine is only eye watering during cold start up and if I am on the loud pedal under boost. Rest of the time I am clean running 14.7-1 on my wide band.
02-17-2012 | 02:26 PM
#23
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From: Canada
I went catless for a while and the smell was too much as stated in an earlier thread when the engine is really cold. It was also smelly when driving on Yonge St on a Saturday night. With the free flow cats there was little or no difference with seat of the pants measurement, but no smell.As I wrote to Murray, I got my X and cats cut and installed at Noyz Boyz in Scarborough for $800 + tax and I have passed the emission test with them (Durham Emission Testing in Pickering)
02-17-2012 | 02:31 PM
#24
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From: Hamilton, Ontario, Canada
Mine is an 89 as well, but i still have a bit of engine rebuilding to do before I even consider the x pipe and cats. I think I will pass on them this time since I may need some of the $$ on unforseen engine items (see the new Crankshaft thread).
The Max Jax is up and running within 15 minutes and is a god send. I aslso have an engine hoist, two engine stands, a bunch of tools ( but not all) etc. Give me a buzz if you want to work on it on a weekend or something.
The Max Jax is up and running within 15 minutes and is a god send. I aslso have an engine hoist, two engine stands, a bunch of tools ( but not all) etc. Give me a buzz if you want to work on it on a weekend or something.
02-17-2012 | 02:40 PM
#25
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From: Washington "Dc"
Yes Rx7s are know to run very rich, particularly at Idle.
The V8s I have owned have been carb cars and/or Big cam chysler motors with a lot of lope at idle. My point is even with a lean burning car at idle the emissions are very irritating (to me) without cats.
The V8s I have owned have been carb cars and/or Big cam chysler motors with a lot of lope at idle. My point is even with a lean burning car at idle the emissions are very irritating (to me) without cats.
02-17-2012 | 02:44 PM
#26
Racer
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From: Stoney Creek, Ont
Geez Livio, if you can drop $5K on a new crank then the x-pipe should be like beer money :-)
Anyway good luck with the engine build. i wil definately take you up on the use of the lift when it comes time to install the x-pipe.
Murray
Anyway good luck with the engine build. i wil definately take you up on the use of the lift when it comes time to install the x-pipe.
Murray
02-17-2012 | 02:47 PM
#27
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From: Washington "Dc"
Whoa, nobody asked you to wave the eco flag regarding the social responsibility for driving without cats. My seasonal non daily driver 928 is like one millionth of a drop in the bucket in the whole scheme of things. Maybe we shouldn't drive cars for pleasure, is that not irresponsible too?? Wasting fuel and polluting the air for nothing but pure enjoyment?
I agree with Greg, if it stinks too much the engine is too rich. Mine is only eye watering during cold start up and if I am on the loud pedal under boost. Rest of the time I am clean running 14.7-1 on my wide band.
I agree with Greg, if it stinks too much the engine is too rich. Mine is only eye watering during cold start up and if I am on the loud pedal under boost. Rest of the time I am clean running 14.7-1 on my wide band.
YMMV, however I was pointing multiple factors and the fact that removing the Cats on MOST cars driven on the street is not the gain some people expect it to be. Some people would like to make informed choices, and you are free to ignore the information I have shared if you like. However do as you like, as in all things the decision (and consequences) are yours to make (And deal with.)
02-17-2012 | 02:49 PM
#28
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From: Hamilton, Ontario, Canada
How dare you bring me back to reality!! Some guys can dream can't they. The thought of all of this stuff and how i was going to be able to enjoy it once the engine was re-built, installed, fix the cosmetic damage that happened in storage etc. was the one of a few good thing to happen today. ...Now where was i, new crank, possible oiling issue fixed with Greg Brown stroked motor... ;-)
02-17-2012 | 03:03 PM
#29
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Just make sure you are not behind me in the SITM parade LOL!Adam: I remember seeing a post from Roger talking about exhaust parts recently and I believe a pair of his hi flow cats for the x pipe was $360 or something like that.
02-17-2012 | 03:05 PM
#30
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Umm but you kinda started this in your OP in this thread. But I digress. Everyone takes their own path for their own reasons. Just make sure you are not behind me in the SITM parade LOL!
Adam: I remember seeing a post from Roger talking about exhaust parts recently and I believe a pair of his hi flow cats for the x pipe was $360 or something like that.
Just make sure you are not behind me in the SITM parade LOL!Adam: I remember seeing a post from Roger talking about exhaust parts recently and I believe a pair of his hi flow cats for the x pipe was $360 or something like that.