Crate EV Motor

The flagship hybrid supercars are primarily doing hybridization to satisfy legislated CO2 emissions regulations.  Secondary reason is Public Relations and Marketing.  The weight of batteries and the hybrid components are at complete odds with what you really want a sports or racing car to do.  Performance is about Power/weight, not power.

Dave

@nottamiata

Thermocouples have a very high output impedance, and while they can be cascaded together to generate higher voltages, they cannot generate the current needed to be an effective energy source.

Thermoelectric conversion of wast heat energy has been worked on by many OEM's and Universities for the past couple of decades.  Look in the SAE technical paper archives and you will find more than a dozen recent papers.  The closest anyone has come to putting thermoelectics in production has been for truck engines which operate at high load a large percentage of the time.  Thermoelectrics problem is the large heat transfer surface required for the cold side and the very low overall conversion efficiency.  Turbo and Rankine - cycle generators are much more effective and cost-effective.

@refirendum

Today you can buy a hybrid Toyota, Honda, or Hyundai with a gasoline engine that has a peak Brake Thermal Efficiency of over 40%.  There are several non-hybrid gas engines that hit around 38%.  The best Formula 1 engine is running at a reported 50% BTE. 

45% is achievable with current known gasoline engine technology in an emissions-legal passenger car.  I have seen some good papers that predict that the real limit with a cost is no object approach, is around 60%.

Looks like some German eggheads have been looking into it for some time:

https://newatlas.com/thermoelectric-cars-improve-mpg/10928/

(Maybe I am only half as dumb as I sound)

Sorry for the partial thread-jacking; I will stop now since there is plenty to say about the original topic. But I hope there is a nice, affordable electric (or hydrogen, fusion, or whatever) powerplant available when The Frog needs a new heart. A 2AR wouldn't be the end of the world, either.

Posted by: @nottamiata

 A 2AR wouldn't be the end of the world, either.

Seems reasonable...

😀

Posted by: @dblotii

@refirendum

Today you can buy a hybrid Toyota, Honda, or Hyundai with a gasoline engine that has a peak Brake Thermal Efficiency of over 40%.  There are several non-hybrid gas engines that hit around 38%.  The best Formula 1 engine is running at a reported 50% BTE. 

45% is achievable with current known gasoline engine technology in an emissions-legal passenger car.  I have seen some good papers that predict that the real limit with a cost is no object approach, is around 60%.

I promised I would stop, I know, but...

<gets out a napkin, flips it over>

If we have several gas engines hitting 38%, then that means that 62% of the input becomes waste heat.

If one could harvest and convert that, at 20% efficiency (an ORC engine can hit that), that's roughly another 12% of the original input, which takes that original 0.38 to 0.50. This would be like adding around 16 HP to a stock 1ZZ-FED.

Sounded better in the pipedream, really. But then again, the emissions hounds would sell their own mothers off in order to get a 12% bump.

This also doesn't factor in all the low-end torque bonuses, which dont affect efficiency (we are still on the napkin here), just the grin-factor. Grins matter; the world needs more grins!

@nottamiata

About a decade ago, Honda did a very nice project to study waste-heat recovery by modifying the exhaust side of a cylinder head to make steam.  In the end they were able to improve drive-cycle fuel efficiency by 6%

@neomr2

At this point it is more of a thought excercize than anything else. The cars these are in are still pretty new, so used parts are in short supply. I'm sure the cost of new parts would be incredibly expensive, to the point I could just swap in more engine for less money. Our current alternator location would also make this a pain to work on. Probably have to have the drivetrain out multiple times to get this set up right. 

I also have a blitz supercharger kit sitting in my dining room waiting for its day... So I'm not sure if I will have a need for more low end once that is installed. If I do, at least the alternator will be relocated to the oil pan where tinkering with it will be much more convenient.

In the instance I do come across one of these systems for a bargain, I will feel compelled to pick it up and see what I can do with it. 

 @dev

Looking at the pictures it appears these usually run on an 8 rib belt, so 6 ribs may still work. If 6 ribs is enough to turn a roots supercharger fast enough to push 12psi or more it's not outside the realm of possibility. Blitz recommends belt changes every 10k miles with the Ogura SC12 compressor, I'd expect similar if someone was using one of these. Also, installing it on a 6 rib system would allow a greater margin of error for alignment assuming an 8 rib pulley is used.

I fully agree with the the statement that a different engine is a more cost effective, and reliable solution. With the amount of $ I've put into the Spyder already, I could've gone with a k24. If I ever have to do it again that's the route I will likely go. I am very familiar with that drivetrain.

@nottamiata

I don't think threadjack is a concern at this point... It appears I successfully derailed this thread back on page two by simply mentioning a mild hybrid system in a thread about crate EV swaps....

@dblotii

I will have to look up that Honda steam stuff... I've never heard of it. Since it isn't being utilized I presume the complexity of the system didn't make the 6% increase a worthwhile endeavor...

Regarding thread jack, there is no such thing or should there be. Just keep posting your thoughts and if someone doesn’t like it too bad, they don’t have to engage in the conversation.  Also no one owns a thread to moderate it’s direction, once it’s created it’s the boards. 

ratio of output to input, rather than input to output.

but point taken on the mathematical definition of efficiency.

sure there's a performance loss when in situation where the motor is acting as a generator, but when you're on the brakes, you con't care how low performance the engine becomes, you just care that when you hit the accelerator, the performance you want is there.

the only performance hit on performance-purpose hybrids is cornering g's and braking distance due to additional weight, which can be offset by tire compound, tire size, and in the case of cornering: awd and torque vectoring.

thermocouple being used as a heat energy recovery system downstream of a turbocharger can possibly reduce the electrical load on a car's electrical system and make the alternator last longer.  it won't be able to power a car at any reasonable size, but they can at least provide the energy to run your dash gauges, your phone charger, or otherwise passively charge a mild hybrid's battery.

if you want to really bump a mild hybrid's effective work per gallon, you can try:

- SCCI engine tech (higher efficiency  due to lower heat combustion event than otto cycle (theoretical 46%) and atkinson's cycle (theoretical 56%))

- turbocharger or supercharger

- thermocouple heat recovery 

- electric motor and hybrid battery

- better aerodynamics

The items that can be designed to output more power or enhance performance:

- the SCCI Engine with F/I

- the electric motor

- the battery

- better aerodynamics

add solar panels to supplement system and reduce gasoline requirements maybe 1-2%

By SCCI do you mean the Mazda SkyActiveX?  My prediction is that it will not make it to the US market due to cost and emissions.  It is not that impressive for peak power and when it is running high load it has conventional combustion.  Only efficient when driven easy.

Dave

Posted by: @dblotii

By SCCI do you mean the Mazda SkyActiveX?  My prediction is that it will not make it to the US market due to cost and emissions.  It is not that impressive for peak power and when it is running high load it has conventional combustion.  Only efficient when driven easy.

 

Dave

yes. when loaded up, SCCI is conventional, but who the heck floors the gas at all times?
I think it will make it to the NA market after it finishes jumping through all of the USA and Canada compliance hoops and the demand builds for it. NA people like torquey large/full size vehicles, so the appeal needs time to build for the general public in the USA.

to name a few compliance hoops:

EPA

- mpg impact on manufacturer corporate average fuel economy

- smog & emissions (general)

California ARB

- smog & emissions (stricter)

NHTSA

- Crash safety tests

- component safety tests

- electrical vehicle power system safety tests (it's a mild hybrid after all)

FCC

- all electronics contained in the vehicle

@refirendum

Remember that the SkyActive-X is lean-burn and therefore has all of the emissions issues of a Diesel.  In addition, this engine is just as, if not more expensive to produce than a Diesel.  I doubt it will make it to the US market and if it does, no one else will follow suit.  There are more sensible ways of making an efficient gasoline engine.

Posted by: @dblotii

@refirendum

Remember that the SkyActive-X is lean-burn and therefore has all of the emissions issues of a Diesel.  In addition, this engine is just as, if not more expensive to produce than a Diesel.  I doubt it will make it to the US market and if it does, no one else will follow suit.  There are more sensible ways of making an efficient gasoline engine.

SCCI burns cooler since it's so lean. the NOx emissions and particulate emissions are much less than that of diesel due to the chemistry of the actual fuel.  It probably has a worse distribution of emission gasses (like a higher percentage of emitted gasses being in the undesirable categories), but there are also less emitted gasses since it's burning so lean. Lastly, since there is much more O2 available in the combustion event, there's a reduction in CO.

The engine is expensive to produce, but i doubt that it's more expensive than a diesel in therms of mechanical part costs. the secret sauce of the tech is in the control software and engine sensors.  

Please elaborate on the more sensible ways of making an efficient gas engine.

Mazda's implementation makes use of both atkinson cycle, high compression geometry, and lean burn SCCI. most effecient non-scci engines use something of an atkinson cycle with high compression geometry, but it's not going to get that last 5-15% or so of combined cycle efficiency that SCCI can bring.