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Mazda’s rotary engine in the age of the electric car

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Re: Mazda’s rotary engine in the age of the electric car

#31

Post by iamthirsty »

coryrc wrote: post #28
sethhochberg wrote: post #16

Earlier quoted context omitted.

They have a pretty narrow power band (produce efficient max power at a small range of RPMs) which always somewhat limited their use for normal ICE cars, but is a pretty workable constraint for an electrical generator. So you have compact size, good power to weight ratio, and power limitations that don't really matter for range extender purposes. Lots of potential. I can't find the article right now, but I'd swear I r…

Then you may as well use a gas turbine, which is pretty much better in every way that matters for generating purposes.

Except extremely complex and usually hard to repair and inefficiently sized for a consumer car.

Re: Mazda’s rotary engine in the age of the electric car

#33

Post by Tagbert »

jmspring wrote: post #9
rootusrootus wrote: post #4

Almost feel bad for GM, the article did not mention the Volt when talking about series hybrids. But I guess it is a Japan-focused news source.

The funning thing is, people I know who have a Volt love their cars. Haven't tried one myself. My family has a couple of paid of Toyota gas vehicles that are 8+ years old and will probably live longer than we will.

I drive a 2017 Volt gen 2 and love it. I drive about 90+% of miles in EV mode and mostly use the gas engine for road trips. It is fun to drive and (other than a couple of common, and easily fixed issues) has been reliable. I do plan to replace it in the next year because it sits very low and has a very low roofline. My spouse is uncomfortable getting into it so we almost never drive it when together.

Re: Mazda’s rotary engine in the age of the electric car

#34

Post by porphyra »

jpgvm wrote: post #3
486sx33 wrote: post #2

Does it produce more low end torque verses a traditional gasoline combustion engine? If not then why is it better suited for electrical generation? Is it more efficient with less load? The article mostly makes it sound like Mazda just loves the wankle and wants to find any possibly way to bring it back - even though it has “high” emissions… so coupling it with a hybrid electric motor makes it happen.. That can’t be t…

Wankels can be made extremely compact so that might have something to do with it, i.e it has both very high power to weight and power to volume specs. I honestly don't know if that is the reason though, perhaps someone more knowledgeable of the specifics of range extenders might chime in but I imagine that is an important factor.

nit: it's spelt Wankel not Wankle.

Also for those who don't know, it's pronounced /ˈvaŋkl̩/ or /ˈvaŋkəl̩/ in the International Phonetic Alphabet (IPA). In German, "W" is pronounced as "V" in English, and the "e" in the syllable "kel" is reduced to a schwa ([ə]) sound, common in many German pronunciations of unstressed vowels.

Re: Mazda’s rotary engine in the age of the electric car

#35

Post by porphyra »

486sx33 wrote: post #2

Does it produce more low end torque verses a traditional gasoline combustion engine? If not then why is it better suited for electrical generation? Is it more efficient with less load? The article mostly makes it sound like Mazda just loves the wankle and wants to find any possibly way to bring it back - even though it has “high” emissions… so coupling it with a hybrid electric motor makes it happen.. That can’t be t…

Low end torque is not that relevant to electrical generation, which typically involves the motor constantly running at a constant rpm. So, since low end torque is a weakness of the Wankel engine, that actually makes it more suitable for electrical generation than for driving directly.

Re: Mazda’s rotary engine in the age of the electric car

#36

Post by porphyra »

skellera wrote: post #8
486sx33 wrote: post #2

Does it produce more low end torque verses a traditional gasoline combustion engine? If not then why is it better suited for electrical generation? Is it more efficient with less load? The article mostly makes it sound like Mazda just loves the wankle and wants to find any possibly way to bring it back - even though it has “high” emissions… so coupling it with a hybrid electric motor makes it happen.. That can’t be t…

I don’t understand why Mazda doesn’t just make a drift-tuned electric car. You could do amazing stuff with software focused on that driving style. A true electric successor to the RX-7 would capture so much attention.

Sports cars, in general, are much loved but seldom bought.

Re: Mazda’s rotary engine in the age of the electric car

#37

Post by Tagbert »

themerone wrote: post #24
mattmaroon wrote: post #15

I have never understood why the Volt Series Hybrid idea never took off. It is more efficient to turn gasoline into electricity and then drive the car with that than to directly connect the engine to the wheels. Is it perhaps that the cost involved is just too much more than a plugin hybrid to make the small extra fuel savings worth it?

Aside from your suggestion violating the laws of physics, that's actually not how the Volt worked. The original concept for the volt was that the engine would only generated electricity, but in production models, the engine was connected to the drivetrain.

Almost - In production models the engine does act like a series hybrid generator under most circumstances. At high speeds, the engine was directly connected to the drive train as it is more efficient to do that. the transaxle of the Voltec system is a marvel of engineering. It supports a dynamic switching between series and parallel hybrid mode as well as using the two separate electric motors for either power delivery or can switch one to regen and can rapidly switch between those modes, too.

Re: Mazda’s rotary engine in the age of the electric car

#38

Post by WalterBright »

coryrc wrote: post #28
sethhochberg wrote: post #16

Earlier quoted context omitted.

They have a pretty narrow power band (produce efficient max power at a small range of RPMs) which always somewhat limited their use for normal ICE cars, but is a pretty workable constraint for an electrical generator. So you have compact size, good power to weight ratio, and power limitations that don't really matter for range extender purposes. Lots of potential. I can't find the article right now, but I'd swear I r…

Then you may as well use a gas turbine, which is pretty much better in every way that matters for generating purposes.

Gas turbine cars have been built, but they tend to set anyone on fire if they walk behind the car.

https://bandimere.com/previewing-the-brakes-plus-jet-car-nat...

Re: Mazda’s rotary engine in the age of the electric car

#39

Post by jpgvm »

porphyra wrote: post #34
jpgvm wrote: post #3

Earlier quoted context omitted.

Wankels can be made extremely compact so that might have something to do with it, i.e it has both very high power to weight and power to volume specs. I honestly don't know if that is the reason though, perhaps someone more knowledgeable of the specifics of range extenders might chime in but I imagine that is an important factor.

nit: it's spelt Wankel not Wankle. Also for those who don't know, it's pronounced /ˈvaŋkl̩/ or /ˈvaŋkəl̩/ in the International Phonetic Alphabet (IPA). In German, "W" is pronounced as "V" in English, and the "e" in the syllable "kel" is reduced to a schwa ([ə]) sound, common in many German pronunciations of unstressed vowels.

Sadly enough I did know that but wrote it wrong anyway! Fixed, thanks. :)

Re: Mazda’s rotary engine in the age of the electric car

#40

Post by 20after4 »

shanusmagnus wrote: post #32

What was the purpose of using the rotary engine in the first place, for ICE cars? From the comments it seems it's maybe lighter for a given power output. Is that it, other than just the novelty of it?

It's about double the power output for a given size / displacement. It's very smooth and high-revving so that makes for a really fun driving experience in a light-weight sports car.
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