North East SSoM Members!!!

Badstang00 said:
Damn man, that makes me wanna :barf:

You make Bryan look like Fabio, even with his shirt off.....

-Mike
you still want to rub lotion all over my man boobs don't you? You like the working man's tan.
I think that I am all set for the VIP show.
I am trying to clean that baked on crud off the windows today. Not making much progress. Might be time for some steel wool.
 
ok and now its sunny and i got the gauge on. Took the car for a drive and got Fing PULLED OVER!!!!! Cop said for excessive acceleration. So anyways, he takes my liscenes and registration, goes back to his car for like 10 mins, so i'm like "$#IT, I'M F'ED"!!!! Anyways, he comes back, hands me my stuff back and says have a nice day and thank you for your service to our country!! WOW that was a close one!!
 
Dan_Soprano said:
ok and now its sunny and i got the gauge on. Took the car for a drive and got Fing PULLED OVER!!!!! Cop said for excessive acceleration. So anyways, he takes my liscenes and registration, goes back to his car for like 10 mins, so i'm like "$#IT, I'M F'ED"!!!! Anyways, he comes back, hands me my stuff back and says have a nice day and thank you for your service to our country!! WOW that was a close one!!


Thats awesome to see a little love and respect. I would probably be asked to put my hands against the car and spread 'em.

-Mike
 
good write-up on A/F ratios

Air/Fuel Ratio
- Ian Staunton
The air/fuel ratio is a common source of confusion to many people. It refers to the ratio of air to fuel exiting from the engine, and it is a good measure (in combination with an exhaust gas temperature gauge) of measuring engine tune. The air/fuel ratio is commonly represented as a single numeral as in 14.7. This actually represents the number of air particles exiting per single fuel molecule (ie., 14.7:1). The 14.7:1 just mentioned is actually what is called stoichiometric - or the ideal air/fuel ratio, at which temperatures are controlled and fuel economy is optimized. Typically cars make best power at about 12.5:1 air/fuel ratio, but this is harder on the emissions parts and sensors, which reduces lifetime.

As mentioned before, exhaust gas temperature, in combination with air/fuel ratio, is a good measure of the state of engine tune. This is because the air/fuel ratio affects the heat generated during the combustion phase of the engine cycle. Fuel acts as a cooling agent for the cycle, and thus having a numerically lower air/fuel ratio - which is considered to be a RICHER air/fuel ratio (ie., richer in the amount of gas exiting) will result in lower exhaust gas temperatures. Similarly, leaning out the mixture by injecting less gasoline causes the overall exhaust gas temperatures (commonly referred to as EGTs) to rise. Frequently a change from a lean to a rich mixture can cool the exhaust charge by as much as 400 degrees Fahreinheit, so this is a very practical matter.

In order to reduce emissions, modern car engines carefully control the amount of fuel they burn. They try to keep the air-to-fuel ratio very close to the stoichiometric point, which is the calculated ideal ratio of air to fuel. Theoretically, at this ratio, all of the fuel will be burned using all of the oxygen in the air. For gasoline, the stoichiometric ratio is about 14.7:1, meaning that for each pound of gasoline, 14.7 pounds of air will be burned. The fuel mixture actually varies from the ideal ratio quite a bit during driving. Sometimes the mixture can be lean (an air-to-fuel ratio higher than 14.7), and other times the mixture can be rich (an air-to-fuel ratio lower than 14.7).
 
How Catalytic Converters work

Most modern cars are equipped with three-way catalytic converters. "Three-way" refers to the three regulated emissions it helps to reduce -- carbon monoxide, VOCs and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required (they are very expensive).

Main > Auto > Under the Hood

How Catalytic Converters Work

by Karim Nice



Table of Contents
Introduction to How Catalytic Converters Work Pollutants Produced by a Car Engine How Catalytic Converters Reduce Pollution Other Ways to Reduce Pollution Lots More Information Shop or Compare Prices


How Catalytic Converters Reduce Pollution
Most modern cars are equipped with three-way catalytic converters. "Three-way" refers to the three regulated emissions it helps to reduce -- carbon monoxide, VOCs and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidization catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required (they are very expensive).







A three-way catalytic converter: Note the two separate catalysts.



There are two main types of structures used in catalytic converters -- honeycomb and ceramic beads. Most cars today use a honeycomb structure.


Ceramic honeycomb catalyst structure



The Reduction Catalyst
The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example:


2NO => N2 + O2 or 2NO2 => N2 + 2O2
The Oxidization Catalyst
The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example:


2CO + O2 => 2CO2
But where did this oxygen come from?

The Control System
The third stage is a control system that monitors the exhaust stream, and uses this information to control the fuel injection system. There is an oxygen sensor mounted upstream of the catalytic converter, meaning it is closer to the engine than the converter is. This sensor tells the engine computer how much oxygen is in the exhaust. The engine computer can increase or decrease the amount of oxygen in the exhaust by adjusting the air-to-fuel ratio. This control scheme allows the engine computer to make sure that the engine is running at close to the stoichiometric point, and also to make sure that there is enough oxygen in the exhaust to allow the oxidization catalyst to burn the unburned hydrocarbons and CO.
 
cold96snake said:
Oh, and being behind all you guys coming out of the show was like sucking on a tailpipe.


Try doing that all the way down to N.H and back :rlaugh:


Congrats to Dan, Mike, and Chris you guys did a good job. It was a great day for a show and I had a lot of fun, that candy cane was :rlaugh: .

Only thing that sucked is when I got home I noticed alot of break dust on my pass side rim and my rear rims never get alot of break dust compared to the front. I figures something must be wrong so I took the car out for a drive and yup had this un gawdly grinding noise comming from the rear tire, almost like metal on metal. Im not sure if the caliper is locked up or what the hell is wrong, its prob just pads but it sounded to bad to actually be the pads :shrug: