[David Schapiro]

Hi folks.

I have decat my 320d (163) about a month ago. I have posted results about power gains somewhere else, so now I will focus on emissions only.

I do live in Chile, and here they are quite severe with emissions.

Regarding diesels, they have two emission requirements (They have A LOT of mechanical requirements as well):

- OPACITY: Having one's car mounted in a dynamometer, there should be no sustained smoke (nor balck or blue) ant any steady speed/RPM.

- EMISSIONS: The unit (m-1??) should not read over 2.5 K Particles per million.


Prior to decat, opacity was no issue, and emissions was 0,62.

After decat, opacity still was ok, and emissions got to 1,55, well within legal parameters.


Close to me was a Nissan diesel truck, year 2010, with 1,9 readings.


So the conclusion is that the BMW diesel engine is so refinated, so efficient, that even without a CAT converter, the emissions still are in the range of other, newer, CR diesel engines.


I couldn't be happier to know that I am not only complying with the law but also way below, and still can enjoy that extra HP I gained.

Hope this helps someone.


David.-

[timmahh]

You're ruining the environment.

[taibanl]

Fail

[timmahh]

FYI OP - Places with strict emissions, like here in California, have visual tests - it doesn't matter if your emissions results are passable, they will see the cat is gone and you'll get tagged for it.

[John 070]

I found out the hard way Midas would not accept my 20% off coupon to remove the 4 cats on my car, even after I asked to speak with the regional mgr.

[Wires]

With modern high-flow cats, I doubt you're gaining that much extra power to be worth the trouble or hassle.....

[David Schapiro]

Hi.

If I have to answer staright to the question "are you now producing more emissions than before or not?", the answer must be YES, and there is no workaround. Guilty. Period.

Now, I have invested A LOT of money by buying a diesel car instead of a Gasoline car (In my country diesel cars pay an extra 11% tax), just to get a less contaminating car, and a better mileage car.

My last car was a gasoline Grand Cherokee (Consumption/pollution monster), and I doubt someone here would have blamed me before, but now I'm running a 2.000 cc engine instead.

Gasoiline cars produce far more Carbon Dioxide than modern diesels, which is the principal reason of the global warming...

Diesels, on the other hand, consume far less oil por mile (let's speak about less emissions per gallon, less Mid-east dictatorships dependancy, Etc).

Also, any modded bimmer here probably has a piggiback chip or a remap, which involves yes or yes a timing curve advancing, which lead to more NOx emissions; SAVE FOR DIESELS, where a remap DOES NOT PRODUCE MORE NOx, for in diesels one don't mess with ignition timing...

Considering my car is a 2.000 cc, and that bigger engines (most bimmers in this forum) swallow much more fuel (producing fuel makes A LOT OF POLLUTION), is also an argument.

Finally, after the decat process, my car yields about 2.4 extra miles per gallon CITY, and about 3.6 extra miles per gallon Highway, so the math is also backing me, in the sense that I'm now reducing the fuel consumption (thus contributing in some extent by other side to global pollution)

Said this, I'M NOT SAYING I'M MOTHER THERESA emissionwise, but I can rest assured that I'm contaminating equal or less per driven mile than ANY gasoline bimmer here, and FAR LESS than any gasoline modded bimmer...

I guess that there are very few guys here who can stand and blame me from contaminating MORE THAN THEM (Otherwise it wouldn't be moral to blame me...).

I really don't want to get into arguing with anyone here, far from it, but I feel I don't deserve to be pointed as "the contaminating member", and less coming from more contaminating machines owners ...

Now, technicallywise speaking, the cost of taking apart the cat was affordable, and the benefits are noticeable. The key here is that this is a Turbo engine, and turbo engines benefit far more from freeflow exhausts that NA engines. In a NA engine, low restriction cats make a bad bet the taking of the cat out, I agree.

Finally, emission tests here also seek for VISUAL inspection (Which I approved flawlessly), and also the emissions measurement (Which I also approved with a big margin left). Here, for gasoline engines the use of a CAT converter is mandatory, but for diesels one must only meet the emissions standars.

Cheers.

David.-

[roadkillrob]

Just remember that the cats help more during warmup, once a modern engine is up to temp, they are pretty efficient and pollute a lot less than the old days. It would be interesting to see how much of a difference the cat removal makes on startup and warmup (first 10 minutes of driving) over having the cats installed.

Also remember, a lot of countries tax cars based on emissions, so the extra reduction in emissions is a major selling point in some countries as it means a reduction in operating costs even if it is really good without the cats.

[David Schapiro]

Originally Posted by roadkillrob

Just remember that the cats help more during warmup, once a modern engine is up to temp, they are pretty efficient and pollute a lot less than the old days. It would be interesting to see how much of a difference the cat removal makes on startup and warmup (first 10 minutes of driving) over having the cats installed.

Also remember, a lot of countries tax cars based on emissions, so the extra reduction in emissions is a major selling point in some countries as it means a reduction in operating costs even if it is really good without the cats.

Well, your's is a VERY interesting question. I'll try to get a cold reading and post the results in the near future, but what I can't do now, is getting the cold readings WITH THE CAT IN PLACE. So it will likely be a guessing game.

David.-

[mikracer]

Haters will always hate. Since when have people on forums against modding? Hes still well within his country's strict emissions laws and gets better gas mileage.

I live in California and its visual inspection is a joke. California restricts you from making any modification to the original motor only because its not factory. I've had a fully built, cammed, boosted LS2 Trailblazer SS that passed the sniffer test without any problems, but would have failed the visual only because I didnt put the CARB sticker on it. Its a joke.