Just read an intriguing article on CNN about iPhones and the manifestations of their carbon footprint. I don’t consider myself a tree hugger but some things in the article resonated with me.

‘The greenest iPhone is the one you already own’

Made a strong case for the right to repair movement, carbon foot print impacts and reduction, efficiency in labor/natural materials usage, protecting the environment etc, etc. One of the many things about the 914 we enjoy is that unlike many newer commodity cars (which BTW there is a shortage of) is that that we can repair/maintain them ourselves and essential parts are available.

This paradigm applies to our 914s and really all things now considered vintage, old, classic, including all classic cars that still function yet remain serviceable and with many years of service life remaining if but for manageable efforts to maintain. Our current disposable consumer model may be reverting to the former ‘built to last’ model past generations relied on and promoted. Seems like the classic car hobby has been brow beaten for so long when in reality we are in the forefront of being environmentally respectful.

The main thing I think of that is not as environmentally conscious about our cars is emissions. But can those be cleaned up easily enough with a bolt on cat? So Ben, will you develop an exhaust for us with a cat or two?

@mb911

If you want to join this thread PLEASE stay factual and don’t turn political. Just the facts ma’am.

Environmentally conscious? My car runs on ambrosia and puffs out toasted marshmallows.

Two things come to mind.
First, many years ago my state required emissions testing of all cars. The older ones without OBD connectors got the CO tester in the tailpipe. if I recall, my -6 always came in well under the limit for that year of vehicle. A properly tuned/maintained car will have a low 'carbon footprint'.

Second, with the number of these cars still on the road (sitting on jackstands doesn't count), and the amount we drive them, our collective contribution to the overall 'carbon footprint' is well to the right of the decimal point.

I would love a cat. It would be nice to have that and a nice dual setup. But considering I paid a case of beer for my used ansa setup...

It would be cool to make them integral with the headers and heat boxes but that would be crazy hot. And expensive.

914s are very green when compared to the millions of "disposable" cars sold every year, and vs heavier "fun cars" (think hp, fuel, consumables, roadways, etc). Few cars on the road are as light as a 914.

And 914s are even greener when they're restored or upgraded with used parts.

I've been driving the same 914 for 31 years, and it returns more long-haul satisfaction and fun than any single car I've owned—and most I've driven. The fact its environmental "sunk costs" were written off a long time ago is a bonus. With that said, I was out for a drive this weekend and its emissions do bother me. While I agree keeping 914s in tune and driving them sparingly makes this a relative non-issue, I've wondered what it would take to add catalysts*. If the cost isn't wild, and the added heat around the 901 isn't an issue, I'm interested. I was following a lowered 1960s Chevy pickup that sounded great (maybe an LS…?), only to notice how bad it smelled. Given its immaculate condition, I had a hard time believing it was out of tune. Then I realized it smelled bad because of how clean modern cars have become.

*I also wonder if the high temps generated by catalysts could be harnessed for smaller heat exchangers.

All it takes to add a cat is late model heat exchangers and mufflers. I think the exhaust manifolds may be the same.

I too would love to be able to squeeze a CAT into my exhaust system. I've looked at small CATs to see if they could be shoehorned into a Bursch muffler but need to do more research. However, as a professional ecologist and wildlife biologist/conservationist, I've been involved in several projects that have given me a fairly deep education in climate change, our energy supply system, and renewable energy. Even though our 914s might be dirtier relative to modern cars, eliminating or cleaning up classic cars is not really part of the climate change solution for reasons that @JeffBowlsby and @fixer34 mentioned. The carbon emitted by the relatively few miles driven by these cars is a rounding error of total car emissions. Still, making my car as efficient and clean as I possibly can is important to me which is a big part of why I'm going to upgrade to a modern fuel and ignition system.

Back to Jeff's point about the environmental cost of replacing things with new, I found the following video interesting. Like any analyses like this, there are many assumptions, and you'd need to adjust for the low miles we tend to put on our cars to make it applicable, but an interesting way to look at whether replacing a car with some more efficient and cleaner makes environmental sense.


https://www.youtube.com/watch?v=L2IKCdnzl5k

1,000,000,000 (1 Billion) cars make up 4% of global emissions. Nothing we do matters.

If you (we) drove 15,000 miles a year for decades then a cleaner car has value, though still minute in the big picture.

I have a cat because EPA mandates my car pass smog for the newest part, being my engine made in 1997, though in reality it didn't matter.

I also read recently that e10 is 4% cleaner than pure gas. Given all the crap we have to deal with, replacing rubber fuel hoses, fuel pumps, injector seals, aluminum derogation, and greatly reduced MPGs, plus higher cattle feed costs, I say it's not worth it.

On the other hand, rooftop solar reduces our need to burn stuff for electricity which is a bigger win for all life.

The problem is that it just isn't that simple. Is the better than nothing? Probably.

But at what cost? Catalytic converteres are not cheap. They are best implemented on a basis of systems engineering vs. a slap on fix.

Cat's run at very hot temperatures (up to 1600-1800F) that if not properly managed at best are going to cost you lost performance, poor emissions conversion efficiency, and at worst become a fire risk if not packaged carefully. The catalytic converter wants to the close the the heads for quick light off. Now you have a whole new cooling issue for air cooled engines. Revist the 911 2.7L six fiasco for a taste of how not to do air cooled engines with a Cat.

A good portion of the reason OEM's moved toward closed loop control (using O2 sensors) of Fuel Injection systems was to better manage the catalytic converter. Modern engines have as many as 4 catalysts and 4 O2 sensors on V-engines. You would really want at least two for the horizontally opposed nature of 914's.

I know a lot of people will find this hard to belive but there are times (like high load / WOT) at which the catalytic converter is running too hot and the FI system begins to dump in extra fuel just to manage the catalyst temperature and cool things down. Failure to keep it operating within the Cat design parameters results in the substrate breaking down, cracking, crumbling and eventually clogging up, resulting in backpressure that degrades the whole system or results in a non-running engine.

Don't want to come off as overly negative. It's just that it isn't as easy as just slapping on a Cat and then magic happens.

Reuse/Recycle is always greener than making something again from scratch.

Nope. Not at all. These are exactly the sort of things I'd want to understand before even thinking of adding a CAT. I've wondered about the late model 914 CATs hung way out back with the muffler and how efficient they are.

It's an interesting topic and one that I've thought about at various times. I do think that older cars that can still pass some kind of sniffer test are probably still not very green. Here in New Mexico, I struggled to get a 76 Alfa Romeo Alfetta, an 85 Volvo 245 turbo, and my current 87 944 turbo to pass emission. They all could just pass the imposed range with good tune, and they all stank to high heaven. Thanks to rolling MY emissions, the 944 doesn't have to pass emissions anymore. But it still stinks! I would like to do an aftermarket cat on it.

For my 914, it seems a Type 4 motor is not a great candidate to get to run really clean. Engine manufacturers have long since abandoned such old tech. But I imagine with good fuel injection and a cat(s), it could do better. I also wonder if this is one more good reason to consider a modern engine swap such as a Subaru motor. Though it does seem many swaps do away with as much emission equipment as possible.

I do feel kind of bad for people who get stuck behind me in traffic when I'm driving one of my classics. But maybe it knocks them out of their appliance-car stupor for just a minute!

^ Not overly negative at all.

All good points, and to the heart of things I've pondered in adding cats (even small or less restrictive ones) on a system (and car!) that wasn't designed for them. And yes on two vs one on an H4 or H6.

Im doin my part!

If these stats are in fact true and nothing we do matters, there is little discussion.

My gut tells me may only be able to purchase electric vehicles at some point soon, maybe 20 - 30 years. At that point we should have more advanced e- technology.

My '86 930 has a cat although the car offsets that good point by burning oil (I think it's the turbo), leaking oil from about 5 different hose/pipes and the front main seal, and getting about 11 MPG.

What I find interesting is the ploy of marketing REALLY expensive (essentially) flip phones to the younger gen. catchy commercials aimed at the tictoc set. What becomes of the old ones and the batteries and phone body? 914s are nothing compared the oil burning/smoking and battered more modern hulks I see on the roads on a regular basis. Climate change? Shit happens when you ignore it long enough. Micro plastics. Potable water. Empty reservoirs. Your grandchildren are f***ed. Proper.

Interestingly enough my 951 passed emissions even without the cat.

Remember, our economic "ecosystem " depends on consumers buying things. Green or not if it bucks the system it's typically not commercially viable.

Good things some of do what we do for the passion of keeping our cars alive.

Most 914's are extremely Green as they never see the road......

I don't think those figures are current. The problem with looking at percentages is that as one sector becomes cleaner, it increases the % contribution of other sectors. Also, looking at percent emissions by sector is only part of the equation. None of this is easy, but some sectors can be cleaned up easier than others. The bottom line is that each cummulative 1000 Gigatonne of CO2 in the atmosphere raises global surface temp 0.45 C and it doesn't matter which source sector reduction come from to have benefit. In other words, it makes no difference whether a tonne of CO2 is kept out of the atmosphere from solar panels or cleaner cars, the benefit to the planet is the same even though the total potential reductions using solar are greater.

With cars, there is a lot we have, and still can do to clean them up. But the most recent data on passenger car emissions I can find estimates passenger cars contributing about 10.8% of global carbon emissions. This is 2020 data from the International Energy Agency and International Council on Clean Transportation.

Perfect! Ours fits this case, and in addition has a good bit of green mold growing on it as well.

Dan

See that in so many other places…

"Environmentally friendly" wiring harnesses made disposable by rodents. Emissions controls systems that must be "ready" to be tested after being driven (and driven) in a certain way. Modern cars without dipsticks that must be driven for XX miles without the hood being opened before the oil level can be checked.




This x1000.

The solar industry has done a terrible job in educating consumers. It took a 928 DIYer's garage expansion > looking into a whole-house generator to get us to consider solar + a home battery. Our rooftop setup was built to deliver 108% of our average use but is making ~170%, for about the same monthly bill (was estimated @ +$11~/month). No more rate hikes, and no more electricity bills after 2030. This is something a lot of people can do.

But I'd still love to clean up my 914's exhaust, too…

I would like to see some environment enforcement to stop the fad among some diesel pickup drivers who modify their trucks to "roll coal" when they want to show off.

no dipsticks? Wow, new to me. Not doubting you. Is that throughout the industry or a specific manufacturer? Is the oil check complimentary? Or a book time bill service? I'm not planning on buying a new car. EVER.

Be careful, the knife cuts both ways. Next thing you know there will be a law that will affect your car.

strangely cats increase CO2 emissions from the car engine.
by converting CO, NO etc into CO2 and a couple of other things including water vapour.

the purpose of the cats was to clean up urban air quality. CO2 was not thought to be so problematic in the 70s and 80s. was regarded as a "harmless" gas.

I saw a Tesla in an accident 2 days ago. The fire station was right across the street and arrived in record time. They could not clean up the scene, they had to wait for a hazmat team to show up. Had the street blocked for a long time. All things have a price...

I'm not a fan of no dipsticks.

My '08 and '14 BMW 328 do not have dipsticks and neither does my '13 Audi A4 although the A4 does have the tube for the dipstick with a cap on it.

One has to run a diagnostic routine after the car is warmed up to get an accurate reading on the oil level.

914 is pretty green as most of them are on jack stands, Right?

No dipstick is one of the worst things about modern Porsches. Well, that, and the infuriatingly un-intuitive electronic e-brake and the lack of a spare tire. Fortunately, our other newer car, a Mazda, has only the e-e-brake…so it isn't all new cars. You can check your own oil in a modern Porsche via the dash—if the level is "ready to be measured." Sort of like the emissions test. Before leaving for AZ, it took 7-8 "errands" over five days to prompt the right conditions to measure my oil.

What was that about green? 7-8 trips to…check the oil? Otoh, there's a lot to like about modern cars—with #1 being the safety.

This video came out in 2009, and was an eye-opener for me:
https://www.youtube.com/watch?v=YHp1GAFQzto

But these comparisons drive the point home—safety tech moves fast:
https://www.youtube.com/watch?v=TikJC0x65X0

Our family has seen more than its (un)fair share of loss due to drunk drivers, so I view daily drivers differently than I once did.

HHO cell?

There are crank triggered ignition systems being developed for stock 914s that will trigger the injectors as well, all monitored by A/F sensors and probably won't need a cat.
The Subaru conversions are already set up like that and if they're like mine before I pulled the engine and wiring harness, they're putting out less emissions than is Federally mandated. That's a green solution that gives the car more power as well.

To answer the second question... smarter EFI. A system from the obd2 era (maf & o2). Our aircooled engines won't like the lean burn of this decades system.

Ideal for that would be shorty headers into a single pipe for the o2, then thru a cat and out the muffler. Means smaller heat exchangers but I recall they got plenty hot so no real loss.

With all those changes you take the 914 from a smog standard of 500/250 ppm to <1 on the sniffer test.

But if you are really serious about emissions you will need to do what Porsche did to meet 1997 standards and go watercooled.

The tech has been out there for at least 15 years for DIY fuel injection systems.
And I say 15 years as that's how long I've owned my 914 and been following the tech.

I'm not sure who is making the crankfire trigger wheels these days, but I have one on my 914 now, as well as full modern EFI running without a cat (but monitoring AFR with a wideband).

The difference between now and 15 years ago is the prevalence of CNC laser/waterjet/etc. cutters, CNC mills, and 3D printers available at the hobbiest level, and not only at a giant machine shop.

Zach

Inputs above remind me that my tired old Type IV was impressively clean in at least one of the measures—blowing right to the limit in one part of the emissions test but scarcely registering in another.

It was very impressive in terms of MPG, too, so I'm not sure I'd mess with a Type IV with factory FI (that's running right). Carbureted 914s, four or six, are another matter entirely…

My '76 914 is a CA car, so it came with a CAT, and the CAT can is still in place. A PO had totally removed its contents.

Is a replacement CAT available for my car? I doubt it, but will check.

Even if it is available, I'm not getting one. Probably cost a fortune and wouldn't make enough difference.....

GN

Admin Edit: Nope - keep the political BS out of this thread.

Matt

This whole "green" thing is a cult of Government as your god.
Everly person in the world that plants and maintains life is GREEN.
Matt
Ya, know like the corn belt? More Oxygen then the whole rain forest!

If you want to join this thread PLEASE stay factual and don’t turn political. Just the facts ma’am. says the man with the bigger stick?

I'm doing my part. $800 Junkyard Subaru engine transplants.

It's interesting to think about and seems most a person can do is based on behavior, not really what they drive. Drive seldom, walk or ride a bike to work, WFH etc.

To me, keeping something older alive is better than tossing it for something new. Heck, my riding mower is a 1994 and still runs like a champ.

I guess for the time being, don't really have to worry about too many new cars being manufactured.

My 914-6 conversion had 993 headers with two CATS. I liked that, but backdated to stock 914-6 heater boxes. I hope I don't have to smell unburned fuel now.

Despite working professionally on environmental issues before retirement, I don't worry about this a lot as far as my several old cars, including the 914-6 bought new 50 years ago, see limited use. But, if pressed, i rely on the final two points of the green mantra "Reduce, ReUse, Recycle".

Having been a mechanic when O2 sensors and computer controlled fuel systems started. I would say that be a major improvement in emissions and drivability. Even without the Cats. When those cars came out around 82 they barely moved the needles on the Sun CO and HC machines. Isn't PMB working on a modern fuel injection system?

Just leave them on jack stands

Sorry late to the party. I have integrated several cats into my mufflers over the years for those interested. It is hidden inside and works but obviously wouldn't pass visually. I use the high flow cats. I would be more that happy to make some up for folks wanting them

Add to the above that Cats need to operate at stochiometric (14.7:1) AFR to be effective at reducing HC, CO and NOx (AKA 3-way Cat). The controller actually dithers the fuel ever so slightly between rich and lean using the HEGO sensor to make it switch. But wait, an air cooled engine needs to run somewhat rich to be cool and stay happy. The Cats on California 914's were obviously the reduction only type designed to reduce HC and CO in rich mode. They work better with air injection (pump) but the NOx is uncontrolled and massive heat can occur if things go horribly wrong. That's why a temperature sensor was added. Bottom line: You need a water pumper (running stoic) to be able to use today's catalyst technology and meet the emission standards.

I have worked in the electric industry for about 30 years. Know what's going to happen when we are all forced into electric cars? You saw what happened in Texas during a cold snap right? Keep that 914 running cause you are going to need it.

Ride a bike or a skateboard if you feel guilty about driving your car.

That's all I've got.

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