Cooled EGR

[Piwoslaw]

Originally Posted by UFO

Maybe you can support that claim. All that I've read about NOx is it requires hydrocarbons and UV to create smog. Modern pollution controls have reduced vehicle HC output to the point that additional NOx control is pointless.

It's not only about smog. From What is Acid Rain and What Causes It?:

Scientists discovered, and have confirmed, that sulfur dioxide (SO2) and nitrogen oxides (NOx) are the primary causes of acid rain.

[euromodder]

Originally Posted by UFO

Maybe you can support that claim. All that I've read about NOx is it requires hydrocarbons and UV to create smog. Modern pollution controls have reduced vehicle HC output to the point that additional NOx control is pointless.

On gas engines.
On diesels, NOx (and PM) remains a serious problem.

Using biodiesel in non-EGR engines, NOx output is further increased over regular diesel.
(EPA test on non-EGR vehicles)

Even so, if I net 10% better mileage with the disabled EGR, my total pollution output with biodiesel is WAY ahead.

Biodiesel has serious advantages over regular diesel, being renewable and having lower HC, particulate, sulphates and PAH emissions.

So why ruin its NOx emissions by disabling EGR

CO2 is not the issue as biodiesel is renewable.

Additionally, I don't have to clean out my intakes anymore. Bonus.

If we all throw the emissions control gear out of our cars, motoring would be a lot cheaper for all ... Bonus.
Or not ?
We'd also be going back to the pollution levels of the 50's-60's-70's.

[UFO]

Originally Posted by euromodder

On gas engines.
On diesels, NOx (and PM) remains a serious problem.

So you and some others claim.

Originally Posted by euromodder

Using biodiesel in non-EGR engines, NOx output is further increased over regular diesel.
(EPA test on non-EGR vehicles)

I accept that, but it's not a particularly large amount.

Originally Posted by euromodder

Biodiesel has serious advantages over regular diesel, being renewable and having lower HC, particulate, sulphates and PAH emissions.

So why ruin its NOx emissions by disabling EGR

Because the engine functions better and lasts longer. And it gets better mileage. Yes there are tradeoffs, but I am not convinced NOx is a serious problem. Acid rain is not an issue in the front range of Colorado, smog was much worse than it is now. My understanding of acid rain is it's caused mostly the sulfur from coal plants.

Originally Posted by euromodder

CO2 is not the issue as biodiesel is renewable.

If we all throw the emissions control gear out of our cars, motoring would be a lot cheaper for all ... Bonus.
Or not ?
We'd also be going back to the pollution levels of the 50's-60's-70's.

I never advocated "throwing out all the emissions control gear from our cars", so please don't put words in my mouth. I am not ripping out the catalytic converters from my vehicles, and certainly not disabling EGR or evaporative controls on my gasser. I also never advocated making modifications solely on the basis of cost savings either.

If you are reasonable I think you will find my actions are proper enough, regardless of whether you agree with me specifically. If you want to be a purist, I'm not interested in your judgment. You will only invite the same on yourself.

[Piwoslaw]

Originally Posted by UFO

Yes there are tradeoffs, but I am not convinced NOx is a serious problem. Acid rain is not an issue in the front range of Colorado, smog was much worse than it is now. My understanding of acid rain is it's caused mostly the sulfur from coal plants.

So if the NOx you produce doesn't effect you locally, then it's not a problem?

[UFO]

Originally Posted by Piwoslaw

So if the NOx you produce doesn't effect you locally, then it's not a problem?

I knew this was coming.

I already stated my position that the small amount of NOx is not a big problem compared to the gain in fuel efficiency, and the marginal amount extra from burning biodiesel is balanced by using renewable, lower carbon fuel.

Maybe I should go back to burning fossil fuels? If you are not happy with my compromises, I can tell you emphatically I'm not happy with yours either. So let's agree to disagree, OK?

[ShadeTreeMech]

Seeing as how you live in Denver, you have to pass emmisions tests, correct? Or is it exempt due to being a diesel?

I lived in CO Springs a few years ago for a year, and have a ton of family in Auroura and surrounding area. I do miss seeing those mountains. I had Pikes Peak as my front door vista during that time, and its beauty is something I miss greatly.

[UFO]

We do have emissions testing specifically for diesels. It's twice as expensive as gassers, and annual instead of biannual. However the only measurable is soot output as opacity, and the standard is quite low. You've got to be smoking pretty heavily to fail. And biodiesel helps with less soot output.

[COcyclist]

I just found this article today. It may be useful for this discussion. It is written specifically for the VW TDI engine (pumpe duese is the injectors driven by the cam as in my car).

TDI EGR system FAQ

"Removal of the EGR will turn on the check engine light which will results in automatic failure during emissions testing and can prevent you from registering the vehicle in many states. Disabling the light or taping over it won't work since they plug in an obd2 scanner which reads your car's computer. There are ways to trick the computer into not showing a check engine light like through a chip tune but tampering with emissions devices is illegal in most places.

The biggest gain is reduced cleaning of the intake manifold. However, ultra low sulfur fuel used in all US and Canadian diesel fuel has greatly reduced major clogging. Biodiesel users report no excess intake buildup although there'll always be a small film. There are only small mileage or power gains from disabling the EGR system since it only operates at partial throttle and idle. Generally speaking, at full throttle, the EGR system is closed by the computer so it makes no noticeable difference in peak power. If you are removing the EGR for reduced pumping losses and the small power or economy gains, bigger and better gains can be made elsewhere. See 1000q: basic performance upgrades for a list of starting performance modifications. Also, the pumpe duse cars use an O2 sensor to regulate the EGR system much more efficiently than non pumpe duse cars. Even newer technologies on the common rail system cars allow more precise fuel delivery and burn, resulting in less intake clogging."

[UFO]

^^^

I've tried that, just pulling the EGR control, and it results in drivability issues and in the short time I tolerated it, no discernable mileage change. Probably because the MIL is set (malfunction indication lamp.) But I am running something else in my Jeep, a circuit that electronically emulates the presence of the EGR system so the engine computer does not trip the MIL. I intend to do the same on my ALH TDI.

[Piwoslaw]

Originally Posted by UFO

I knew this was coming.

For me, using less fuel is part of how I try to pollute less. If I had the option to reduce fuel consumption and certain pollutants while increasing certain others, I would research the matter and make an educated choice. I believe this is what you did in good faith and I respect that. If you are not indifferent to NOx pollution on a global scale and your post cited above was only worded unfortunately, then I take back my comment.

How a certain engine reacts to adding/removing EGR seems to be a highly individual thing. Some report milage going up, others down. I read recently that in newer cars the ECU has so much control over the engine that EGR operation is almost unnoticible, so we have cleaner cars without sacrificing performance.

I would also like to ask everyone to keep the focus on the differences between cooled and non-cooled EGR. There many threads on EGR in general, so please move any off-topic discussions there.