Best place for a Cat?

[rayaapp2]

Poor fuel control will kill that cat...

 

Do yourself a favor and put an AFR meter on it, and insure you are at 14.7 under a majority of conditions, you will kill it. A catalyst is a pass-through device, it is NOT a 'scrubber'---if your AFR is correct, you will have no HC to make your eyes water.

 

The ONLY time a catalyst is operational is during transitions (acceleration, WOT, decel if you don't have fuel-cut like EFI does.)

 

If you idle or go down the road and get fumes and smell exhaust YOU ARE TOO RICH.

 

And you will burn up or overheat that catalyst in short order if you don't fix that first. You don't slap it on and make it all better. Fix the problem, don't bandaid it! If you smell fumes, you are not 'adjusted correctly'!

 

I guess I didnt touch on Cat operation.

a two way cat functions as Tony describes. In older cars equipped with these cats will not be functioning at idle, cruise, or WOT.

WOT I believe is a dwell issue. Its still functioning and is lit off, but its not efficient. You can see this by watching the O2 sensor. The O2 doesnt swing the mixture. The O2 only samples the swing in mixture.

At idle on most of these old cars its hard for the O2 sensor to stay "awake". This is why they integrated heater circuits into the O2. The heater sensor does help cold start emissions, but also idle conditions where the exhaust is just to cold to support the O2 AND catalytic reaction. There isnt a heater circuit in the cat and if you idle for long enough even after a good long lite time it will cool off and not function again.

At cruise the cat is lit off and the O2 is swinging. The cat though is doing very little(hopefully) though. Other emissions devices whether they be EGR, AIR, or combustion chamber design are in effect here to bring the efficiency up of the combustion process. If your cat is working had under cruise... you have other issues.

 

Its not that it wont work under these other condition... in 2 out of 3 it is catalyzing... it just isnt making an effective change in a properly working system.

 

A TWC system changes in one way. It will in most cases be lit off at idle and in most cases even before full engine operating temperature. Generally it will be working before closed loop operation of the fuel injection system. It will work in colder situations because the catalyst is not the same as the older two way cats. In most cases I believe the figure is 500* and its lit.

 

Manufactures are in the process of making a sustainable catalyst that is effectively lit off from startup... but sustainable is the keyword. Drastic reductions in cold start emission is what they are after... I can only wonder what this "space age" tech cat derived from NASA will cost.

 

 

Ground Horse Burger Paddies.

Edited January 21, 2011 by rayaapp2

[BLOZ UP]

And that is the line of thought that has resulted in the Jan 2009 law that mandates all Cats be ODII certified. Techs that just replaced cats to clean up emissions for a smog gave the rest of us new headaches because of their lack of diagnosis and understanding of the whole system. Lets just slap another on it will clean up the emissions.... yeah for what 2 weeks. Guess they will be buying a new cat in 2 years... or 1 if Gross Polluter.

The best way to reduce emissions is to get a complete and efficient burn of the A/F mixture in the chamber. 90% of the emissions devices revolve around this statement. Catalytic Converters and AIR being the 2 I can think of off hand that do not.

 

I never said run the car rich as possible and put a cat on and it will be better. I said they reduce pollution. I'm aware that the car has to be running at stoich for the cat to work properly. The debate was whether or not they work during cruise, idle, transients. I am purportedly wrong about that.

Edited January 21, 2011 by BLOZ UP

[rayaapp2]

I never said run the car rich as possible and put a cat on and it will be better. I said they reduce pollution. I'm aware that the car has to be running at stoich for the cat to work properly. The debate was whether or not they work during cruise, idle, transients. I am purportedly wrong about that.

 

 

And what happens when you run it as lean as possible?

 

You missed my point. The cat is not a clean it all up device as Tony mentioned when he stated it was NOT a "scrubber". I was not particularly poking at you either. The statement whether it came out wrong or not that you had made was what I was commenting on. A general lack of knowledge about what a cat is and how it works is easily miss-interpreted by the general public as A. Evil Emissions Performance Robbing Device or B. That thing that will make their car pass smog. So when you say "Cats are actually one of the best devices to reduce emissions, IMO. " I have to disagree. That is the line of thinking for idea B. As I stated before the BEST way to reduce emissions is to get a complete and efficient burn of the A/F mixture in the chamber. not use a cat. If you ever spend any time at all using a 4 or 5 gas analyzer on an older carb'ed without a cat car you will find this out for yourself...

If your a Ca smog tech then you know that figure Ca BAR gives you is 'something like' 90% emissions can be cleaned up BEFORE the cat.

[BLOZ UP]

the BEST way to reduce emissions is to get a complete and efficient burn of the A/F mixture in the chamber.

 

Isn't that a given? Of course the rest of the emissions equipment won't work as well if it has worse stuff to start off with?

[cygnusx1]

Sidebar: It would be interesting to see emission plots of a "properly" tuned L24 carb'd engine vs federal and non-fed L28 efi. I would also like to see those emission plots against a current LEV engine (pre and post cat) to see how far engine design has actually come.

 

 

 

 

...back to your regularly scheduled skooling.

 

 

[rayaapp2]

Isn't that a given? Of course the rest of the emissions equipment won't work as well if it has worse stuff to start off with?

 

Well, NO.

 

If it had been then the thread starter would not have been asking about installation of a cat to rectify a stinky exhaust situation...

 

Example:

As of last month MY 1971 240Z stunk me out on decel, but I had known the culprit for many months. My AB valve diaphragm was faulty causing an eye burning situation upon decel through my missing hatch seal(esp with the driver window down). A few weeks ago I acquired a used, but functioning unit and no more eye-burning stink not even a little stink even with a missing hatch seal and the window opened at varying degrees... Every piece of my original emission equipment is installed and functioning. No stink!

 

So back to the ~90% (I seem to remember a higher percentage but for the sake of this conversation 90 works). What I was trying to get at in regards to noxious fumes is that there would be no need for a cat on a Z if it were to be properly tuned(And actually Tony already stated that "You can get JUST as clean on HC/CO simply with carb adjustments and AIR without putting a flaming hot brick next to your transmission." on page 1 of this thread). A cat only cleans up a small amount of that last percent... Its not gonna solve stink.

[rayaapp2]

Sidebar: It would be interesting to see emission plots of a "properly" tuned L24 carb'd engine vs federal and non-fed L28 efi. I would also like to see those emission plots against a current LEV engine (pre and post cat) to see how far engine design has actually come.

 

 

 

 

...back to your regularly scheduled skooling.

 

If a ULEV had more O2 content it would be cleaner than the air you breath in any metropolitan area, but that is with the cat. Testing pre-cat is still DAMNED clean. Were talking 1% or less in reductions. If they didnt swing the fuel LRL the cat would never lite off.

One thing to keep in mind is that a L24 was not subject to NOx or HC emissions. The L28 I believe was held to the "new" HC standards for smog.

Edited January 22, 2011 by rayaapp2

[Nigel]

 

Later cats (OBD2 timeframe) do more things. But early bricks are very limited in their scope of cleanup. The reason they are 'effective' at stoich is that NOx is at it's minimum near that point.

 

 

I don't think this is correct. Every source that I've read indicates that NOx is formed at high combustion temperatures, and these occur at stoich. Hence, the introduction of the EGR valve, to inject a small amount of inert exhaust gas into the combustion chamber to lower combustion temperatures, and reduce NOx. Unfortunately, this also reduces engine efficiency.

 

Nigel

'73 240ZT

[rayaapp2]

I don't think this is correct. Every source that I've read indicates that NOx is formed at high combustion temperatures, and these occur at stoich. Hence, the introduction of the EGR valve, to inject a small amount of inert exhaust gas into the combustion chamber to lower combustion temperatures, and reduce NOx. Unfortunately, this also reduces engine efficiency.

 

Nigel

'73 240ZT

 

 

Yes NOx forms at 2500+*F

 

That is one of the best graphs you will find. I have a similar one from the CIAT.

 

The website from which I pulled it is actually good reading so far.

Alternative Fuel lean combustion 101

Edited January 22, 2011 by rayaapp2

[BLOZ UP]

Well, NO.

 

If it had been then the thread starter would not have been asking about installation of a cat to rectify a stinky exhaust situation...

 

Example:

As of last month MY 1971 240Z stunk me out on decel, but I had known the culprit for many months. My AB valve diaphragm was faulty causing an eye burning situation upon decel through my missing hatch seal(esp with the driver window down). A few weeks ago I acquired a used, but functioning unit and no more eye-burning stink not even a little stink even with a missing hatch seal and the window opened at varying degrees... Every piece of my original emission equipment is installed and functioning. No stink!

 

So back to the ~90% (I seem to remember a higher percentage but for the sake of this conversation 90 works). What I was trying to get at in regards to noxious fumes is that there would be no need for a cat on a Z if it were to be properly tuned(And actually Tony already stated that "You can get JUST as clean on HC/CO simply with carb adjustments and AIR without putting a flaming hot brick next to your transmission." on page 1 of this thread). A cat only cleans up a small amount of that last percent... Its not gonna solve stink.

 

Really? I was under the impression that cats drastically reduced HC, NOx, and CO1 emissions--at all times, but most efficiently at stoich levels.

 

So what your saying is, if I tune my Z to stoich, it's nearly as clean as running it at stoich with a cat. The cat only starts working to compensate for Accel enrich., etc.?

Edited January 23, 2011 by BLOZ UP

[Tony D]

The debate was whether or not they work during cruise, idle, transients. I am purportedly wrong about that.

 

No 'purportedly' about it, you are wrong plain and simple. As Ray mentions they are a transient device. When the fuel control system is in operation, they are doing VERY little.

 

Your comment that "cats are one of the best ways to clean up emissions IMO" sounds like a PeggyHillisim. Kinda sounds good, but doesn't hold up to scrutiny.

 

The BEST way to control emissions is have a functnioning fuel control system on the car, then the Cat is just along for the ride.

 

Like I said, emissions controls are VERY misunderstood by many people.

 

The ONLY catalyst that is 'working all the time' is the proprietary Englehard Designed low-temperature catalytic radiator on the front of some Ford products. Seems the HC in the AMBIENT AIR was enough in some cases to throw the EFI system calibration out of whack far enough to affect vehicular emissions during testing. The only way to get the system compliant was to preclean the ambient air of Hydrocarbons---so the old joke about a car driving down the road and putting out cleaner air than what it takes in, has actually become a reality.

 

If a Catalyst was a 'clean up device' then the HC in the ambient air wouldn't have mattered---it would have 'scrubbed' the exhaust flow on the back end.

 

That is not what happened! They pre-cleaned the air using Englehardt technology and low temperature catalytic substrates applied to the radiator of the vehicle to clean the air, and relocated the air uptake for the engine to inside the engine bay. No CAI system will be CARB Legal on that car---the radiator is an integral part of compliance of the vehicle!

 

 

If you have ever SMOG tested a mid 90's SAAB you would be amazed. It's VERY hard to detect when a catalyst has failed. They have such a sophisticated and accurate load map of the fuel system on those cars, they run clean with or without a catalyst! Likewise, early CVCC engines didn't NEED a cat to comply with emissions requirements, but Federal mandate had them installed. They were VERY small. They did nothing to comply with the emissions requirement other than fill a governmental box saying they had one on there because it needed to be on there.

 

Yes, if your EFI is working correctly, your catalyst does nothing other than a transient cleanup.

 

Keep in mind Federal cars didn't have them till 77 or 78. EFI ALONE met emissions standards. For California, it was again governmental MANDATE that they be installed. If you have ever emissions tested one with and without a catalyst (and the EFI is functioning as designed), there is VERY little difference in the readings. In fact, look at the CARB SMOG testing regimen, or the IM240 Dyno check for Federal Emissions and realize there are no big accelerations taking place, but rather very slow transitions. It's because they KNOW the catalysts DO NOT pick up hard transients well, and they would fail 100% of the cars---and the voters would be outraged.

 

One thing worth mentioning was that there IS a 'NAPS' version of the L28 in some Japanese Sedans and Coupes---this used an ECCS system to control the fuel, not EFI like the older cars. The more sophisiticated computer controled the fuel better to meet the much more stringent JIS Standards for those particular years. The EFI Fairlady Z S30's and S130's had FAR cleaner emissions than US Specification (including CA) vehicles. They had the same Catalyst part number...but the fuel control systems were totally different in the critical years. As the conditions standardized later in the production run, they went 'back' to older technology as it would still comply. But there were some interim vehicles in the 78-80 time frame that had some pretty sophisitcated ECCS Controls on N/A engines! I have a 1978 Fairlady 280Z(X) with stepper motor idle air control, an O2 sensor, and an emissions sticker than has '0' for allowable emissions in one of the boxes (HC/CO/NOx, forget which!) Same catalyst as for the USA, though! It's the fuel control, not the scrubber out back that made the difference!

 

The biggest thing IM240 Revealed was that, indeed over the older Idle and 2500 test (and you KNOW the catalyst is not active at idle in an old Z!) many more cars failed because they were in such poor state of tune that they could not accelerate the dyno as they should have and needed far more throttle putting them into open loop to move from section test to section test---and as a result puked out HC and CO like crazy and failed the test.

 

When your car is running correctly, the cat is just along for the ride.

Edited January 23, 2011 by Tony D

[Tony D]

RE: Ray's Graph

 

Our Stationary "Lean Burn" engines ran Methane in a Lanova-Style Precomb Chamber, to ignite a 22:1 AFR main combustion chamber. If you look at what the chart says you will see 22:1 for Methane is DAMN WELL FAR CLEANER than running at Stoich. You will find it hard to run that lean on a variable speed engine like a car becuase the transitions are so difficult. But in steady-state full load applications it not only returns the least fuel burned, but generates the least emissions. Then we had a five-stage Englehardt Catalyst Bed (6 foot X 6 foot X 6 Foot Stainless Steel Box with five separate honeycomb substrates in it) to SCRUB the gas. We had to inject stuff into the exhaust stream or run replaceable beds because of their being consumed during operation.

 

As for my 73, I believe I was running around 17 to 18.5:1 for the old Idle/2500 test and passed with flying colors to 83 Catalyzed specs. It was hard to drive (understatement) I was on the verge of lean misfire. SU's tuned to 'lean best'... And it was CLEAN. I want to say 0.5% CO and 125ppm HC, but I think HC was double digits.

 

If this thread is still active when I get back to the states later this week, I'll go to the glovebox and pull the sheet, I still have it. It was a real eye-opener to me that I could get the car sooooo clean with 'old technology'... I still have that emissions printout from 1990!

[BLOZ UP]

No 'purportedly' about it, you are wrong plain and simple. As Ray mentions they are a transient device. When the fuel control system is in operation, they are doing VERY little.

 

Your comment that "cats are one of the best ways to clean up emissions IMO" sounds like a PeggyHillisim. Kinda sounds good, but doesn't hold up to scrutiny.

 

Ok, I was wrong. Very wrong, and trying to sound like I knew what I was talking about. I'm just parroting information I hear, trying to act like I know a lot. I see what you're getting at.

[rayaapp2]

 

I pm'd in an attempt to keep the thread clean... oh well.

 

"Really? I was under the impression that cats drastically reduced HC, NOx, and CO1 emissions--at all times, but most efficiently at stoich levels.

 

So what your saying is, if I tune my Z to stoich, it's nearly as clean as running it at stoich with a cat. The cat only starts working to compensate for Accel enrich., etc.? "

 

 

 

Your kinda right, but not quite grasping the whole thing. BTW this is not something totally easy to grasp either. Most people I have seen try and learn this can take several weeks of study to come to a good understanding of how these systems all work together.

Cats DO catalyze well "NEAR" stioch. If you were able to get a stioch mixture or even stay close to stioch all the time the cat would not be able to catalyze. If you look at the graph I posted you will see that there are only 2 emissions we are concerned with at stioch. NOx and CO2. There isnt any O2 or CO2 to do anything with in the catalytic process. In a TWC you would not even be able to break down the NOx completely at stioch as it still requires extra O2 to end up with N2 and O2(This is a chemistry aspect where you get the same amount out as you put in). At stioch you are getting as close to a full efficient burn as possible leaving you with no 02, CO2, or HCs for the cat to work with.

 

Applying this to your Z and yes you can run it as clean without a cat as with for the older standards. I have my original 71 up to BAR 84 catalyzed standards with no cat and a damaged AB valve. Im sure thats what Tony was saying about his 73 as well when he mentioned that his car met 83 catalyzed standards. This does not mean you will get it as clean as a newer car. But yes you can tune the L series as to get to a point where you will not have enough CO, O2, or HC to support a catalytic process. You would actually have to dirty up the mixture(slightly richen) to have the cat function... and as I stated earlier in that thread you will risk burning the cat up by either going to rich (CO) or to lean (HC). A side note here HC = incomplete burn as in what happens with a lean miss-fire or any other event where you do not reach a total burn of the A/F mixture. And YES Tony you can hit that mark and still have drivability though I think mine is at the mark not below on some of the gases(HC's in particular).

 

So why use a cat? On older cars it was a band aid and for years manufactures tried to work out the kinks. (mid 70s - early 80's)

A combination of light emissions standards and crude systems let them just band aid the car and meet the mandate requirements. Nissan is not a good example of this BTW. Ford, GM, Chrysler, etc are with their carb systems and development into electronic carbs with fuel metering rods, and then finally onto crude fuel injection systems. Nissans use of the Bosch system that was well developed by 1979 put them WAY above the bar by almost 10 years!

Most manufactures really didnt start to get a working system out until fuel injection systems were worked in (1981-1989). Being able to swing the mixture is the key. Now once you have a good EFI system in place and a good cat you can actually go from mid 90% emissions clean up to 99.9% emissions clean up... leaving now only things like cold start emissions to be cleaned up, which is the current area they are working on.

 

 

For reference

BAR 84 Catalyzed std is a 4 gas analyzer O2, CO, HC, and CO2 no load testing two speed idle "TSI".

 

BAR 90 is the first 5 gas analyzer reading all the current emissions.

This is still a no load test TSI.

 

BAR 96 SMOG Check II 5 gas analyzer and first loaded testing called a Advanced Simulation Mode or ASM test. 15mph @ 50% load and 25mph @ 25% load.

This is the test that an L series would fail without a cat.

 

The cat doesnt only start "working to compensate for Accel enrich., etc". Its just has more to work with at those events. You will have to have some basic chemistry, that graph, and a basic understanding of fuel mapping to completely understand this. Having the mixture swing rich lean rich lean keeps the catalytic process going in the cat at almost all times(except two way cats at idle). These transition areas fuel the catalytic process without the swing. Even at WOT the cat is doing something(It may be limited, but its catalyzing what it can) and is staying lit without the swing... Hold the engine at WOT for a long period of time and you risk having a chemical reaction with the substrate that will result in a melt down. This will happen at a certain temperature that I cannot remember off hand. Basically you end up dumping to much fuel into the exhaust at WOT over long periods of time that its far enough away from stioch to damage the cat.

 

 

This situation is the result of mandates as Tony has sort of mentioned above. Basically as the tests change the manufactures have to find a way to cover these new areas of criteria. Mandates hit the manufacture long before the tests are worked out in most cases. Up currently as I mentioned before is cold start emissions. Manufactures are designing a cat to meet this new standards... Someday there will be a test to cover these standards Im sure. Its evolved from the 2 gas idle tests measuring only O2 and CO to what it is today. They are up to measuring part throttle loaded tests and measuring 5 gases. There are still gaps that they are trying to get covered by new mandates ie cold start emissions.

Other recently in effect mandates would be Evaperative Emissions testing and the most recent snap throttle tests looking for tail pipe smoke that would be indicative of loaded untested(even by any current testing) excessive HC's.

Edited January 23, 2011 by rayaapp2

[Tony D]

"So why use a cat? On older cars it was a band aid and for years manufactures tried to work out the kinks. (mid 70s - early 80's)

A combination of light emissions standards and crude systems let them just band aid the car and meet the mandate requirements. Nissan is not a good example of this BTW. Ford, GM, Chrysler, etc are with their carb systems and development into electronic carbs with fuel metering rods, and then finally onto crude fuel injection systems. Nissans use of the Bosch system that was well developed by 1979 put them WAY above the bar by almost 10 years!"

 

This is true, and if you look to VW for the lead, they went with 1st Generation Bosch Technology in 1968 to comply with the FIRST generation of automotive emissions introduced in 1967. VW made the change on their 'new' car models then, and converted Beetles in 1975 to AFC style Injection (like our Datsuns.) Datsun was working with the first generation BOSCH systems in competition in the early 70's, and had a functioning ITB system in place on rally cars in Europe running Alpha-N/Speed-Density mix programming without O2 trim as early as 1971! Their success with racing the EFI convinced them this was the way to go for performance vehicles, and went that way. In fact, the 1973 Tokyo Auto Show introduced the new 260ZE model with a very familiar emissions control system on it---the second generation Bosch EFI AFC controller we got here in the USA in 1975!

 

GM and the other Big Three was a 'bandaid' exactly as Ray says---they bet on lobbying efforts to skew the standards, delay implementation of the mandates and let them keep in production with what they had without any R&D (which was ironic in GM's case as they had functioning Analog EFI in high efficiency small engined cars--The Cosworth Vega---in the same timeframe as the Datsun. Management by committee, FAIL!)

 

And to clarify I met BAR90 Standards as it was 1991 when I last legally smog tested one of my vehicles since this past year...

[zeiss150]

WOW! There are some really pompous people posting on my thread. Maybe I shouldn't be allowed to post here any more because of my ignorance. what kind of crap posts is that. for those of you that believe your are the end all be all of Z car information you can suck it! I've been posting her for years and I never come across such crap.

 

None of you asked me if I had adjusted my carbs ... did you! None of you asked me if I replaced the hatch seals (yes even the antenna drain) did you!

 

Maybe I've adjusted the carbs to the point at which the care runs too lean and then adjusted it back to the point of proper afr's. Maybe I did but you'll never know ... because none of you asked. Oh yeah... my tail pipe is pointed at the ground.

 

There were a few good posts and I appreciate your CONSTRUCTIVE help and information. I always want to learn new things about my Z car but I want to learn it from people that aren't trying to prove how much smarter they are that the rest of the morons on the web site. Maybe follow what your mother told you ... if you don't have anything nice to say... DON'T SAY ANYTHING AT ALL!

 

Now, I understand that I might get busted by the mods for this post but at this point I don't care. I was going to post some pictures of my INSTALLED, WORKING catalytic converter, but now ... not so much. I'm just going to let people figure it out on their own.

 

The two or three people (and you know who you are) that messed up my thread with snotty comments are probably the kind of people that have a lot of good information but no one to give it to, because no one can stand be be around them. Please go to another Z web site or at least please don't comment on any threads that I start.

 

Sincerely, Matt A.K.A zeiss150 Just so you know who I am.

Edited January 26, 2011 by zeiss150

[Nigel]

Ignoring all the naysayers, I put a cat in my Z 7 years ago (sorry, I couldn't find any good pictures of the location). I have no regrets doing it. No, I don't have before and after emissions test. However, I also have no complaints about exhaust fumes in the car, and everyone who rides in it comments on how civilized it is. That could just be because my Z is fuel injected, and I've tuned it pretty well, and the previous exhaust system was rather leaky. But, even if it does nothing, for $100 and a couple of horsepower, it's such a tiny investment, that it was worth it to try. And despite road racing, and drag racing, and some tuning mishaps, I've yet to melt it.

 

A friend of mine had a cat put on his Z with triple Webbers, and he swears that it made all the difference in the world in his Z. I'd have to agree that it doesn't smell like a refinery in his car now. Another friend tried a cat in his Z with twin SU's, but I don't think he had as much luck.

 

Theory isn't always everything. Try one out and see if it works for you. Again, it's such a small investment, that you don't have much to loose if it doesn't work, and others have had success with them.

 

Nigel

'73 240ZT

[2eighTZ4me]

Zeiss - with a post like your last one - you've likely pigeonholed the number of people that can and will actually answer a question the next time you have one. This thread is chock full of GOOD and (somewhat) relevant information for people that want to learn. Just because you don't like the "attitude" by which this information was presented, doesn't discount the validity of the information.

 

"I always want to learn new things about my Z car but I want to learn it from people that aren't trying to prove how much smarter they are that the rest of the morons on the web site. "

 

What did you do when you had a teacher in school you didn't like? Did you just fail the class?? Or suck up your ego and do what you had to do to LEARN?

 

FWIW - I didn't "ask" you if you'd replaced your hatch seal - I told you that it could be a major factor in the problem you're seeing (ref. post #12). I guess because I didn't "ask" you if you'd replaced it - then the information is not relevant? Jeez man - you've just screwed yourself out of two or three people that actually KNOW their stuff and would be willing to help you in the future.......not so much anymore. Shame that people let their feelings get in the way and discount what is right in front of their nose. You'll learn.......

[Tony D]

Putting a cat on a car with EFI and putting a cat on one with SU's is apples and oranges.

I have to appreciate the high level of technical expertise here, and adherence to scientific methodology when doing these sort of swaps.

 

Please keep in mind, because someone discusses the technical aspects of a subject does not mean they are 'stuck in theory'---I am a firsthand proponent of field testing to prove or disprove theory.

 

But don't be stupid about it! Ignoring proper application warnings is just that: stupid.

 

So take your ball and run, don't share the success story, don't give us before and after emissions readings. That really helps everyond on the board. Thanks for that, man!

 

I guess the next guy will simply have to do it on his own and report the results...if he chooses to do so after being INFORMED of the things to be wary of when setting up the project.

 

[2eighTZ4me]

So - in summation, THE best place for a cat..........(wait for it.........................) is to leave it in the bag!!