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Old 12-06-2008, 03:25 PM   #92 (permalink)
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Yep emissions for heavy duty diesels are producing more NOx than CO2. although you divided the grams by 10 instead of 65 miles traveled.

Yes the LD50 is administered all at once but the test for non-common application chemicals is over several hours testing periodically to check vitals on animals to see if more extensive testing is needed, but tests for more common chemicals Benzene for example is tested on vast numbers of animals over animal lifespan and includes larger mammals as well.

The LC50 of Benzene or the amount needed to cause near immediate death in 50% is over 3,000 PPM. Chlorine is 293 and most swimming pools are 5 PPM. Much closer to an LC50 than the air anywhere in the world.

Also most Chemistry TA's are going to absorb much more than LD50 of Benzene at some point in their career as well as hearty-doses on a monthly basis for anyone teaching organic. Its not that terribly deadly.

We both do want the same thing. All I am saying is that gasoline engines have a cat to weed out a few grams of HC at the cost of several MPG. if you snip that and improve exhaust efficiency(how fast can you get it away from the engine for free without breaking the valves) you drop the amount of CO2 you produce per mile because you get more miles per gallon. For instance if you did that on the above mentioned civic with variable trans you could probably get it to the 50-55 mark instead of the 40-45 mark. The noise regulations that mandate the engine has to go 4-2-1(also EPA) robs substantial amounts of power and FE, but if you still have a restrictive cat in place then it takes over and you see very small gains.

Pop, both port your exhaust out under the drivers side door(or passneger depending on exhaust and engine layout) with some baffles as it exits the car and you gain tremendous HP and MPG.

I originally thru-piped my cat and muffler for power gains and it was easily noticeable. Changing the exhaust pipes is a little harder and requires some fabrication because finding 4-1 pipes is difficult since its not legal for sound pollution reasons.
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