Exhaust Emission Standards

Improving Reliability and Longevity to Any Sporting Machine

In this article I will discuss what should be the first priority improvement to any car, and especially to a sporting machine.

The answer begins with a look at the problem. And the problem is governmental intervention into the automotive design process. If automobile designers were given a free hand as they pretty much were until 1968 cars today would be a lot more fun to drive, faster, and more economical. Our job as high-performance freaks is to outsmart the G-men, to figure out what is best for us and our cars, and then compromise only enough to beat the inspectors. This is politely called “by-passing” not breaking the law.

As an attorney I can tell you that until you are proven guilty you have not, in the eyes of the law, done anything deserving punishment. I can also tell you that there are so many laws restricting so much of human activity that most members of the Silent Majority unknowingly break enough laws every day that were they caught and successfully prosecuted, they would spend a lot of time in custody.

But I digress. For our purposes it is sufficient to know or to find out how our (your) particular state inspects motor vehicles. All states inspect for safety-related items such as lights, brakes, window glass, etc. A few inspect for compliance with some exhaust emission standard. That is, an actual emission test is made of your car’s exhaust at the inspection station (for example, in N.J.). Most states have a visual inspection rule (for example, N.Y.). The inspector is supposed to conduct a “visual inspection… to determine the presence and correct installation of any air contaminant emission systems or devices which are required by state or federal law… ” (Section 301 (c) (2), Vehicle and Traffic Law of the State of New York).

Practically speaking, then, if your car looks stock it will pass 90% of all state inspections; and since all state inspection tests are done with the engine idling, if your car has a “clean” exhaust at idle, it will pass 100% of all state inspections.

The road to the high performance shop should now be clear:

(1) All procedures should be no less than professional quality.

(2) All work should look like “it came from the factory that way.”

(3) Exhaust emissions should not exceed the prescribed limit under the parameters tested, i.e., at idle.

Now we are ready to analyze the various aspects and effects of government regulation on our poor suffering automobile. These can be divided into the following five general systems, typically present on most cars:

– Evaporative Emissions Control

– Catalytic Emissions Control

– Exhaust Gas Recirculation

– Modified Ignition Timing

– Carburetion/Jetting/Metering (richness) and Throttle Controls

The Evaporative Emissions Control principally involves trapping crankcase and fuel tank vapors and feeding them into the induction system to be burned, rather than venting them into the atmosphere. No real harm is done to performance by this system. There are just lots of hoses, seals, and a two-quart container of explosive gasoline vapor locked up in the trunk. If you take it off, be sure to vent the gasoline tank.

The Catalytic Emissions Control is simply the catalytic converter under the floor. It gets hot (1,000 degrees or more). It gets clogged. It gets expensive to replace (up to $500 or more). It shortens the life of the exhaust system. And it acts like a cork on horsepower. Remove and replace with straight pipe, but watch the idle emissions carefully.

One side benefit is that catalytic converter equipped cars are generally carbureted and timed better (by our standards) than equivalent non-converter equipped cars.

Exhaust gas recirculation is a system which literally feeds some of the burned exhaust gases back into the induction system to contaminate the incoming mixture in order to lower peak combustion temperatures, thereby reducing nitrous-oxide formation. It also robs horsepower which is produced by the very same heat. EGR has no effect at idle.

Need I say more?

Author: Unknown


Submit a Comment

Your email address will not be published. Required fields are marked *

Restoration Categories

Updates by Email

BMW 2002 T-shirts

Today’s BMW Poll