Cat conv. and performance
- Thread starter yadawho
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Nelson84, well thanks for the advice on moving. But actually I'm quite content living where I am. 300+ days of sunshine, no snow, and the roads are some of the best of anywhere I've lived. ( MI, GA, CA, TX ) Plus the hunting is great.
I'm not gonna beat a dead horse on the cat issue anymore but I did find some very interesting information on catalytic converters and performance.
[FONT=Verdana, Arial, Helvetica, sans-serif]H[/FONT]igh efficiency catalytic converters are the key to high output and low exhaust emissions. They’ve been cursed, damned, gutted, removed and praised, and depending upon your priorities, they’re either the best or worst thing to happen to automobiles in the past 30 years. Since they first appeared on 1975 model year vehicles, catalytic converters have made a significant impact on both pollution and performance. Unfortunately, that impact hasn’t always been positive on both accounts. Owing largely to early designs, which were very restrictive, catalytic converters are widely viewed as horsepower killers. And while even the most free-flowing converter will increase exhaust back pressure, the effect on performance can be minimal. Independent dyno testing has repeatedly proven that most engines produce just as much power when equipped with high efficiency catalytic converters as they do when running through straight pipes. So it just doesn't make sense to drive a car that isn't emissions legal.
That statement may seem to fly in the face of reality but catalytic converters have changed dramatically over the years. The first converters to find widespread usage were filled with pellets coated with precious metals. As hot exhaust gases pass over the pellets, (also called beads) their coating serves as a catalyst and instigates a chemical reaction intended to transform exhaust pollutants into harmless compounds. Specifically, when unburned hydrocarbons come in contact with platinum and/or palladium, the resulting oxidation process transforms them into carbon dioxide and water. Similarly, when carbon monoxide meets palladium and/or rhodium, the resulting oxidation process converts it into carbon dioxide.
Although “three-way plus oxidation” type converters were prevalent during the 80s, that’s no longer the case. With improvements in washcoat technology, and improved control of air/fuel ratios, the need for additional oxygen has been eliminated. Some vehicle manufacturers have continued to use oxidation converters on some models, but typically that has been done to use up inventory. As an example, the Corvette and Camaro Z/28 were equipped with oxidation converters through 1991 and 1992 respectively. But when the LT1 engine replaced the L98 (1992 in Corvette, 1993 in Camaro) three-way converters with no air tubes were incorporated.
In theory, a catalytic converter should last the life of a vehicle; it has no moving parts, the bricks are not consumed by the catalytic reaction and the cases of all original equipment converters are made of stainless steel, so rust isn’t a problem. In the real world, an excessively rich air/fuel ratio, oil or antifreeze in the exhaust system or physical damage can send a catalytic converter off to the great recycling yard in the sky.
Physical damage is the easiest to diagnose. If a converter is bounced off a curb or speed bump, or is struck by freeway flotsam, the ceramic bricks can be fractured. Once that happens, it’s just a matter of time before the bricks start rattling around inside the case, beating themselves into oblivion.
The information above was copy and pasted from this website, feel free to visit this site and educate yourself further. Thanks, and have a great day.
http://randomtechnology.com/technical.html
Oh, and I think Hib Halverson has an excellent article on how to improve the LT1/LT4 ZR-1 exhaust to the tune of 28 hp over the stock exhaust system. You'll find that article right here on this site. Its in the Knowledge base section under C4 exhausts. Enjoy.
I'm not gonna beat a dead horse on the cat issue anymore but I did find some very interesting information on catalytic converters and performance.
[FONT=Verdana, Arial, Helvetica, sans-serif]H[/FONT]igh efficiency catalytic converters are the key to high output and low exhaust emissions. They’ve been cursed, damned, gutted, removed and praised, and depending upon your priorities, they’re either the best or worst thing to happen to automobiles in the past 30 years. Since they first appeared on 1975 model year vehicles, catalytic converters have made a significant impact on both pollution and performance. Unfortunately, that impact hasn’t always been positive on both accounts. Owing largely to early designs, which were very restrictive, catalytic converters are widely viewed as horsepower killers. And while even the most free-flowing converter will increase exhaust back pressure, the effect on performance can be minimal. Independent dyno testing has repeatedly proven that most engines produce just as much power when equipped with high efficiency catalytic converters as they do when running through straight pipes. So it just doesn't make sense to drive a car that isn't emissions legal.
That statement may seem to fly in the face of reality but catalytic converters have changed dramatically over the years. The first converters to find widespread usage were filled with pellets coated with precious metals. As hot exhaust gases pass over the pellets, (also called beads) their coating serves as a catalyst and instigates a chemical reaction intended to transform exhaust pollutants into harmless compounds. Specifically, when unburned hydrocarbons come in contact with platinum and/or palladium, the resulting oxidation process transforms them into carbon dioxide and water. Similarly, when carbon monoxide meets palladium and/or rhodium, the resulting oxidation process converts it into carbon dioxide.
Although “three-way plus oxidation” type converters were prevalent during the 80s, that’s no longer the case. With improvements in washcoat technology, and improved control of air/fuel ratios, the need for additional oxygen has been eliminated. Some vehicle manufacturers have continued to use oxidation converters on some models, but typically that has been done to use up inventory. As an example, the Corvette and Camaro Z/28 were equipped with oxidation converters through 1991 and 1992 respectively. But when the LT1 engine replaced the L98 (1992 in Corvette, 1993 in Camaro) three-way converters with no air tubes were incorporated.
In theory, a catalytic converter should last the life of a vehicle; it has no moving parts, the bricks are not consumed by the catalytic reaction and the cases of all original equipment converters are made of stainless steel, so rust isn’t a problem. In the real world, an excessively rich air/fuel ratio, oil or antifreeze in the exhaust system or physical damage can send a catalytic converter off to the great recycling yard in the sky.
Physical damage is the easiest to diagnose. If a converter is bounced off a curb or speed bump, or is struck by freeway flotsam, the ceramic bricks can be fractured. Once that happens, it’s just a matter of time before the bricks start rattling around inside the case, beating themselves into oblivion.
The information above was copy and pasted from this website, feel free to visit this site and educate yourself further. Thanks, and have a great day.
http://randomtechnology.com/technical.html
Oh, and I think Hib Halverson has an excellent article on how to improve the LT1/LT4 ZR-1 exhaust to the tune of 28 hp over the stock exhaust system. You'll find that article right here on this site. Its in the Knowledge base section under C4 exhausts. Enjoy.
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