Allowable exhaust gases

[tjts1]

Originally Posted by rmay635703

??? US government definately infers the requirement of a variety of equipment OBDII for example implicitly requires a cat.

State law here at least also requires a cat regardless of the emissions output.

Try passing emissions without a catalytic converter.

[rmay635703]

Originally Posted by tjts1

Try passing emissions without a catalytic converter.

My father has owned several non-cat vehicles that passed the sniffer.

[some_other_dave]

Which standards? The current ones for new vehicles? If so, that would be very interesting.

-soD

[oil pan 4]

It would be easy for me to pass 1985 emissions with a fuel injected LS3 from 2007 and up with no emissions garbage.
That is if I had an inspection to pass.

If I had to get inspected after I installed the new generation engine in my old car and lets say it put out HC, CO and NOx emmissions at 1/4 or less of the standard I would fail the visual inspection for no converter (that is why you get one and hollow it out and stick it on).

[tjts1]

Originally Posted by some_other_dave

Which standards? The current ones for new vehicles? If so, that would be very interesting.

-soD

Exactly

[Diesel_Dave]

Originally Posted by some_other_dave

Which standards? The current ones for new vehicles? If so, that would be very interesting.

-soD

Good point. Most folks have no idea just how far the regs have come down.

Consider heavy-duty diesel truck engines (semi truck engines):
In 1988 the NOx limit was 10.7 g/hp-hr.
In 2007 the NOx limit was 0.2 g/hp-hr.

That's 53 times less NOx! 2007 is only 1.9% of what it was in 1988!

FYI, at the same time particulates also went from 0.6 g/hp-hr to 0.01 g/hp-hr--60 times less.

[Duffman]

Originally Posted by Diesel_Dave

Good point. Most folks have no idea just how far the regs have come down.

Consider heavy-duty diesel truck engines (semi truck engines):
In 1988 the NOx limit was 10.7 g/hp-hr.
In 2007 the NOx limit was 0.2 g/hp-hr.

That's 53 times less NOx! 2007 is only 1.9% of what it was in 1988!

FYI, at the same time particulates also went from 0.6 g/hp-hr to 0.01 g/hp-hr--60 times less.

Ding Ding Ding! And the government is not mandating SCR to get there, most manufacturers are using it but not all. Also I think that is the 2010 standard not 2007.

[Duffman]

Good link for the OP, but its for diesels and not comprehensive.
Emission Standards: USA: Heavy-Duty Truck and Bus Engines

[Diesel_Dave]

Originally Posted by Duffman

Ding Ding Ding! And the government is not mandating SCR to get there, most manufacturers are using it but not all. Also I think that is the 2010 standard not 2007.

It was a phase in between 2007 & 2010, so you're correct.

You're right about SCR, too. The standards don't mandate HOW any of the emissions get met--that's up to the manufacturers. In some cases the levels do imply a certain technology. For example, it's virtually impossible to go to 0.01 g/hp-hr of particulates without a DPF (or at least some form of aftertreatment--you just can't get engine-out PM that low).

SCR is for NOx control. You're right that not all manufacturers are going with it. For the manufacturers it's a matter of picking your poison. If you go with SCR you can let the NOx fly out of the engine (to get great FE), and let the SCR clean it up, however, then you're going to have to use a lot of DEF (diesel exhaust fluid), and you have to pay for the SCR system (both in initial cost and maintenance cost & DEF). The SCR alternative is running high amounts of EGR. That means crappy FE, but low NOx. EGR also has it's cost associated with it (initial, maintenance, & extra fuel). So it's a complicated issue, like I said--pick your poison.

[oil pan 4]

The Science Of Diesel Emissions Reduction - Diesel Power Magazine
http://ecomodder.com/wiki/index.php/Water_injection