What about a cvt for Pagodas?

[66andBlue]

We have had many discussions here about modifying engines in our cars or transplanting engines from other models.
There are probably even more posts about 5-speed ZF or Getrag transmission changes.
I am curious whether any of you R&D tinkerers have ever thought about putting a modern continuously variable transmission into our cars.
https://en.wikipedia.org/wiki/Continuously_variable_transmission

1. Would that not solve two shortcomings at once, that is, high fuel consumption and high noise levels?
2. What would be the "sweet spot" for a 230SL or a 280SL?

[stickandrudderman]

Ooh yuck!

[Jack Jones]

CVT's belong in snowmobiles.

[GGR]

I'm a big fan of CVTs! One of my to be projects is to mate a cvt to a rotary engine and fit the whole thing into a Citroen DS. The basic idea is to fit a crazy engne and a crazy transmission into a crazy car. The expected result would be an automotive interpretation of the flying carpet concept.

I'm not sure I would consider a CVT on a Pagoda though.

[66andBlue]

Ooh yuck!

Stick, do you despise ALL automatic transmissions?

I'm not sure I would consider a CVT on a Pagoda though.

Why not as a replacement for the standard automatic?

And this is for Jack: https://www.youtube.com/watch?v=TWUix_5ztNE
The WRX is a fast snowmobile, eh?

[mdsalemi]

Of all the crazy-a** modifications out there, Alfred, you choose to proffer a CVT?

For those that have not followed this: DAF (that Dutch automaker nobody's ever heard of) came out with the first CVT on their tiny and low-HP cars in the late 50s. It was derived from similar items in the machine tool trade. Nobody paid much mind to it; then Volvo bought DAF, and Ford bought Volvo and voila--you had upsized CVT models on 2005 Ford Freestyles (I had one!). In a word, weird, and didn't offer me anything but reduced fuel economy and a change in engine/transmission noise.

GM had them, and abandoned them. So did Audi, and Ford, and Volvo. I think Subaru still may have them. Nissan had them, too. Maybe they still do? It's the "rotary engine/Wankel" of transmissions. They'll always be someone trying to evolve it. Meanwhile, evolution and development continues on other technology.

The trick is, automatics have evolved, big time. A modern, dual clutch 6, 7, 8 or even 9-speed automatic is a thing of beauty, and that kind of transmission [industry wide] evolution is why CVTs will remain a niche if they don't disappear entirely. Automatics have gotten so good, it's why standard transmissions are not as common as they used to be either!

[66andBlue]

.. I think Subaru still may have them. Nissan had them, too. Maybe they still do? ...

Yes they do! So does Mercedes and a lot more: https://en.wikipedia.org/wiki/List_of_automobiles_with_continuously_variable_transmissions
You need to keep up with the 21st Century, Michael!  
You should go to a Subarau dealer and drive an Outback or perhaps a WRX, maybe you'll change your mind.

[stickandrudderman]

I have no objection to autos, just don't like CVT AND EVEN THAT IS JUST A PERSONAL THING, NOT FOR ANY TECHNICAL REASON.
AND I JUST REALISED I LEFT CAPS LOCK ON AND AM NOW SHOUTING, SORRY!

[66andBlue]

Driving a car with cvt is indeed strange, you hit the pedal , the rpm shoot up immediately and then the car tries to catch up in speed, weird.
That was my feeling driving a Subaru Outback recently.

I am still curious what you experts estimate the fuel saving would be from a cvt that maintains the rpm at 3500 (close to the peak of the torque curve) which is about 72 miles/hour with a 3.69 differential.

[Cees Klumper]

I drove a DAF 55 with a CVT through one winter to college when I was 19. Drove great and I really liked the transmission. Nowadays my daily transportation is a Honda scooter, 30 HP and very quick, has a CVT which works very well.

[Garry]

My wife’s small MB A Class has the CVT and to be truthful I hate it but it has not missed a beat from new and is now 10 years old.  Kate thinks its great. I am not sure that they are that good of fuel usage.  My large VW Toureg gets better fuel consumption than the small A Class.

Garry

[Travis71280]

CVTs can get better gas mileage in theory by allowing the engine to operate at its most efficient engine speed and maintain it as the car accelerates, unlike current autos and manual transmissions that have to change gears. It would also allow for the best performance on paper since the engine can stay in its power peak the whole time without having to move through the powerband.

In the real world though, most cvt designs involve using a belt and a variable pulley which does not have quite the mechanical efficiency of a manual transmission or automatic with a lockup converter, thus any benefit from the engine not having constantly rev up and down is neglible. Also these transmissions can rarely support any kind of power (its getting better, but I don't think it can support 400hp+ yet, or at least for long) due to the fact it's having to transmit power through a belt.

For our cars it is definitely possible to retrofit a CVT, since our cars don't produce a lot of power. If you want to do it, by all means go for it, its your car. You'll definitely get the cool factor for it not being done on our cars before. As for me though, I prefer transferring power through gears than a rubber belt, but that's just me.

[Jack Jones]

I have driven many of the Van Doorne CVT variants and I realize they have a purpose but to me they feel like a bad clutch. The auto manufacturers are using them more every year since they are cheaper to build then manual boxes and soon you will not be able to purchase a manual in North America.  

[GGR]

For long the main limitation of CVTs was that they could not take much power. This is now gradually being sorted out. The remaining problem is that people are a bit surprised by the way they work, as they expect to "feel" gear changes. It's a bit like if for a century, cars' breaking systems were such that cars would slow down in phases. And then would come a system ensuring a smooth loss of speed as we know it. Most people would feel uncomfortable with it and some would hate it.

[GGR]

DAF (that Dutch automaker nobody's ever heard of)

May be in the US. But remember, this is an International Group.

[GGR]

I have no objection to autos, just don't like CVT AND EVEN THAT IS JUST A PERSONAL THING, NOT FOR ANY TECHNICAL REASON.
AND I JUST REALISED I LEFT CAPS LOCK ON AND AM NOW SHOUTING, SORRY!

You have one on your plane, with its variable pitch propeller. Not sure you want to replace it with a gear box!

[66andBlue]

..
For our cars it is definitely possible to retrofit a CVT, since our cars don't produce a lot of power. If you want to do it, by all means go for it, its your car. You'll definitely get the cool factor for it not being done on our cars before. As for me though, I prefer transferring power through gears than a rubber belt, but that's just me.

I have absolutely no clue how to go about doing this!  
But one thing I did learn from reading, a rubber belt is not good enough, it should be a flexible steel belt.

My curiosity was peeked by a remark made by Mike Salemi in the 5-speed gear box discussions "why stop at 5 and not go to  6" and I just extrapolated that to infinityCVT.
And since he actually drives a car with a cvt, or what Ford call an eCVT, I thought he actually might be interested in such a conversion. Oh well ..

[stickandrudderman]

Good point GGR!

[mdsalemi]

You need to keep up with the 21st Century, Michael!  
You should go to a Subarau dealer and drive an Outback or perhaps a WRX, maybe you'll change your mind.

Alfred, I offer that they (CVT) will remain as they are: a curiosity that will NEVER make it to mainstream, and NEVER replace a good solid automatic. As I mentioned, give me a modern automatic, 6+ speeds.
I'd go to a Subaru dealer, but we don't have many here in Michigan. They appear to all be in Vermont or something.  
No, but seriously, I had a CVT, and it is as you described. Strange was the word you used?

Why not just adapt a modern MB installed transmission, such as that from an SLK or something?  You know, that new 9G-Tronic? THAT would have me interested! Not a has-been or trying to be, CVT. For those that reminded me that MB has CVT, aren't they only on very small, very low HP A and B class cars? I don't think they are on anything in the USA, are they?

Travis, I don't have one--Ford long abandoned it, only putting on the Freestyle and certain 500/Montego models ten years ago. I did have it for probably a year and 20,000 miles or so in 2005/2006 on my Ford Freestyle, and remember before anyone starts bashing Ford, it was a Volvo platform with the transmission having a genetic line directly back to DAF. It was the model CFT30, made by our great friend ZF (you know, the brains behind the holy grail of Pagoda transmissions, the 5-Speed?) I didn't necessarily consider it strange, just different and offering nothing over what preceded it, and what replaced it. Which explains why it had replacement! I didn't have it long enough to suffer with it, as people who own it for years suffer all kinds of strange noises apparently. I didn't get this in one year. It was just shall we say, "interesting".

Yes, Gael, I'm sell aware that this is an International Group. But remember DAF sold mostly into the Dutch market, for a limited time, a curious little vehicle. It was, and will remain, a peculiar niche long gone. Thus I offer it is indeed classic and collectible; even noteworthy. But well known? No. Perhaps a bit better known than Gogomobil...I did actually go to the factory once, in 1971 when I spent the summer in the Netherlands.

[GGR]

These DAF cars' notoriety in Europe was well beyond their sale numbers. People knew their technical specificity, and once you heard one in the street you would not forget it. It is true that some manufacturers like Audi have reverted from cvt back to "normal" transmissions. But some others like Subaru have adopted it recently. I'm not sure they are finished. In any case, what make them interesting to me is their concept, like the rotary engine and the hydro-pneumatic suspension.  I would like to have all three together in one car. Granted, The Pagoda may not be the best test bed for that. And the Pagoda crowd may be a bit too conservative for that type of revolutionary concepts. But a Citroen DS would be the perfect car for it!

[mdsalemi]

But a Citroen DS would be the perfect car for it!

what, the Citroen didn't have enough uniqueness? You want a rotary engine, CVT, and the hydropneumatic?
Let us know when it's done.

The reversion isn't only Audi...but GM, and Ford as well. Just don't think it will ever make it mainstream. Subaru, sure. They are pretty much a niche manufacturer, and that's where the unique like a CVT will always fits in. Boxer engines and AWD, now CVT...they may sell on the coasts and in the mountains but they don't play in Peoria! They are most popular in Maine, Colorado and Washington; state, not DC! They are on a tear for sure, but Toyota sells more Corollas alone than Subaru does cars, and Subaru is at near production capacity. Yeah I see the occasional WRX with coffee can muffler around, rear wing flying high, and some youngster driving it--and with less than 3% of the USA market they are indeed a niche. An interesting niche, not boring, but niche nonetheless.

Let us know your your FrankenDS comes on when you sort it all...

[66andBlue]

Mike,
is you Ford PEV with eCVT already gone again?
http://www.sl113.org/forums/index.php?topic=20643.0

[GGR]

Let us know your your FrankenDS comes on when you sort it all...

Well, it's not going to be tomorrow, as my current job doesn't leave me with much free time. I've looked into the Audi CVT as it's a transaxle which would fit the DS layout. The problem is that it communicates with the engine via can-bus technology. Some aftermarket transmission ECUs support it but I would need to know the "language" which is usually kept secret by the manufacturer. Another option would be to use the DAF 66 system which is much simpler but I would need to have it sent from Europe as these cars were not imported in the US. I will be in Europe end of December, I will see if I can locate something.

[mdsalemi]

Mike,
is you Ford PEV with eCVT already gone again?
http://www.sl113.org/forums/index.php?topic=20643.0

Good point, Alfred--but I've been talking about the CVT I used to have, a more conventional model that has been abandoned. The PEVs we have, I don't drive too much; as they are relegated to wife and daughter. Most of the time however, they are in pure EV mode where like most electric cars you do not know you have a transmission at all. The electric engine provides full torque at all RPM. The transmission or eCVT is only noticeable when the gas engine is on; however there is so much noise from this little gas engine that it drowns out all other sounds. For us, 95% of the time the gas engine is NOT being used, just because of the way we use those cars; they are used for short trips where we always have full battery power. In fact, both cars were filled up with gas on March 27, and it was two months later on May 27 when they needed gas...effective MPG is 70-90.

Don't consider what is on this full PEV as anything that will stand alone. When have you seen this eCVT on a Ford non-PEV? When have you seen a 4-Cylinder, Atkinson cycle gas engine on a pure gas (non-hybrid) car? You don't. This is one peculiar, extremely complex power train designed as an integrated package. It's also incredibly expensive; these cars had sticker prices $42K-$44K, which explains why few are buying them. They make no economic sense, really. We just got a good deal for 2 years.

BTW they both will be turned in next July when the lease expires. (n.b. at that time I'll sell my Level 2 charge station too--which is good for anything and everything but a Tesla) While they are interesting, and my electric bill has only gone up $30 a month, they are so darned complex that I would shudder to think of paying for some service bill down the road. In January, one of the cars had the battery heater fail, and it was a month to get the part. Who wants to live with that? The batteries are like human beings: they are ONLY comfortable between 68-72 degrees F.

Which brings the ugly truth about PEV cars that few ever discuss: temperature. These cars do NOT like it hot, and they do NOT like it cold. (perfect for Solana Beach I guess!). The range will be cut in half if you use the heat or a/c on a hot or cold day. Some of the battery power is used to heat the batteries when cold. There are complex algorithms used to turn on the gas engine when the ECU determines it needs to move the fluids. Open the hood and you see massive cables, looking like a power station, not a car. It's been fun, but they'll go back.

[Benz Dr.]

According to the graph in post # 8, my car with a ZF 5 speed and a 3.92 rear axle should be running close to 95 MPH or slightly higher at 4,500 RPM, which was what I was doing on 696 ( near Detroit ) while returning from Joe's place last Sept. No wonder it seemed so fast!