I've had numerous conversations with people and the general consensus is that in general, emssisions don't do a whole lot. That much of the system in theory may sound good, but in actuality probably does almost nothing. While a Cat doesn't bother me the whole "smog pump" and "air tube" setup bewilders me. What in gods name are all those tubes possibly doing. The cat has 1000* exhaust gas going through it, why does it need it's own TINY separate line feeding off the exhaust manifods to "pre-heat" it.

Also how does the EPA run the set emission standards? How is it that I could take a car, put a non-emissions engine in it, get 25MPG, but be considered "illegal" and be failed when possibly the same car in stock form doesn't get 25MPG.

What is the deal with parts per million? I mean, I know gearing of rear/transmission plays a huge role, but burning 1 gallon of gas is burning 1 gallon of gas. A cat will take out some pollutants...I know I'm confusing fuel efficiency with cleaner emissions, but does that mean you can burn less fuel, get better MPG, and still pollute alot more then a car getting worse MPG? I mean, would that not equal out, your parts per million is less, but you burn more fuel....I don't know, I'm an idiot....just something I was thinking about. In actuality I think I'm just pissed that in a year I'm going to have to find a way to pass emissions....it's not like there's that many people building engines anymore...jeez...let me take off my emissions.

 

In the emmisions testing, the biggest things they look for is NOx and CarbonDioxide. Those are concidered the 2 biggest enimies to the enviroment. You usually get high NOx when the engine is running lean and the other when it is running rich. You cats need the air pumps to keep them from clogging.

The whole idea behind the cat is to separate NOx into O2 and N and turn CO into CO2. The air tube isnt used to preheat the cat, to preheat the cat the engine runs rich to make that happen.

The deal with parts per million (ppm) is that the enviroment produces so many on its own so I think that they are trying to get so cars produce less then that, put then usually one car produces more ppm then the whole enviroment produces so it doesnt equal out.

 

The "AIR" or "smog" pump is set up differently on different year/engines. The 3rdGen used a catalytic convertor that had two distinct "beds"... a "reducing" bed to break down the chemical bond and turn the NOx into N2 and O2.... and an "oxidizing" bed to burn the HC's to H2O and CO2, and the CO to CO2. The AIR pump has a divertor valve on it. At startup, it directs the air to the head pipe/manifold to held burn the rich startup mixture and generate heat, speeding up the heat up rate in the cats. They don't work when they are cold.

Once you get the engine running normally, and there is enough heat in the system to keep the catalytic convertor "hot", the divertor valve redirects the air flow to the middle of the catalytic convertor. The front bed is "reducing" the NOx, and the extra O2 is added in the second bed to provide even more O2 to "burn" the CO and HC.

In the 4th Gens, they use a monolithic convertor, which allows a homogeneous mixture of the two catalysts required, and the seperate O2 supply to the cat is not required. Hence, in the LT1 engines, the AIR pump only runs for a few minutes to "pre-heat" the convertor.

The possible conflicts between emisisons and fuel economy is considered in setting the standards. The reason that most EFI system use 14.7:1 as the closed loop control A/F ratio is because that is the point at which the best balance of fuel economy and emissions is found. Actually, 14.7:1 is not the "best" for any of the three pollutants that are controlled - HC, CO and NOx - but it provides the best balance. As poointed out in a post above, you could reduce CO and HC by running a lot leaner, but then NOx would skyrocket. You could reduce NOx even further by running a bit richer than 14.7:1, but you would cause CO and HC emissions to elevate. And, 14.7:1 isn't necessarily the best for fuel mileage... 15.8:1 would probably be better, but then the NOx becomes a problem, as noted in the post above.

 

Some of the smog laws are kinda retarted. I just failed the NJ test this year for high HCs. Tures out the car was running way rich due to a bad injector.

Anyway, I have heard that an ls1 puts out less polutants (sp?) than an average lawn tractor. I would think they should do something to fix the crap coming out of factory smokestakes (fly into Newark Intl and all you see is the damn smoke).

Injuneer, just saw your from Jersey, I'm over in Momunth county, you?

 

Not even the ***** would have come up with an organization as strickt and cruel as the EPA. I understand keeping the enviroment clean but a blanket law is crappy. Why does a low production sports car have to meet the same standard as a mass produced ****box? Also after a car is bought and paid for there should be a rule that you can do anything to it as it is not a massive enviro problem when a few ppl modify there cars. Im sure the Mustang and Camaro fans would never compete in pollution compaired to the School and City busses.

I hate inspections sorry just cant see why i cant modify my car without being thought of as a baby killer by the tree huggers or govt.

 

Isn't it all about money? Like....companies pay to be allowed to produce more pollution and they share credits....doesn't the state get money for keeping emissions?

 

Isnt there a law in CA that states that if the motor is bigger then 500 in3, that it doesnt have to pass the tail pipe test?

As far as the low production car meeting the same as a high production car, I would think it would cheaper for the car companies to meet the same standard with the low production car as the high production cars. Also as far as the exemption to emissions for paid for cars, think about it, I would think that if there was an exemption like this, I would think that you would see a spike in modded cars. Also you could call a car burning oil modded, it has modded piston rings.

 

Obviously, world history is not your area of expertise.

 

I really don't think you'd see that much of a spike in modded cars. Most people don't buy a brand new car and void the warranty by messing with it.

It's only like 2 decades of cars that got reamed, pre 78 or 76 are exempt, so it's only like 80+ that are screwed over. I think beat cars that are not correctly kept up are a bigger problem then modded cars.

 

I actually have a minor in history. I used the example to illustrate how regulated and unfree our American lives have become. Its my car I paid for it and I should be able to modify it and drive it on the weekends when ever I want. It is safe it cant hurt anyone else. I think it should have to be safe. But not allowing me to work on it as my hobby and my own personal property i find that a little invasive. Screw the EPA bunch of ***** if you ask me.

 

This has deteriorated to a "Lounge" topic.

Closing