RX-9 Rotary Rumor Mill Churning Again

[serialk11r]

Originally Posted by madfast

KERS by itself is not going to cut it. the future of hybrid sports cars is a 2 motor hybrid system that uses the motor as the primary means of propulsion, and a powerful engine to turn the second motor as a generator and to provide power to the wheels.

I wouldn't be so sure about that, a fully electric "transmission" is quite expensive and is far more difficult to design for high power than a mechanical one, not to mention not any more efficient at any given power level. A Porsche 918/proposed NSX type motor + mechanical transmission setup is even more cost prohibitive.

I do agree with you that KERS by itself is not going to cut it. A race car spends most of its time near maximum power output, a street car almost never uses even half its rated power, so it makes no sense to have a separate KERS system that is not closely integrated with the engine.

A possibility I see for increased brake regeneration is using an alternator like device on the front wheels instead of permanent magnet motors. Using a very high excitation current at low duty cycles, they could generate quite a lot of power at reasonable efficiency, and have very little mass penalty, especially because friction brake thermal capacity can be reduced.

[madfast]

Originally Posted by serialk11r

I wouldn't be so sure about that, a fully electric "transmission" is quite expensive and is far more difficult to design for high power than a mechanical one, not to mention not any more efficient at any given power level. A Porsche 918/proposed NSX type motor + mechanical transmission setup is even more cost prohibitive.

huh? toyota has used the eCVT for years. and i think the LS600h with 438 hp has enough hp to be considered high power. in fact the only reason why HSD hybrids are not more powerful is that they have a small battery. they use an "oversized" motor for the regen, not for motive power. so one can see if they wanted to, they could easily tweak the HSD system a bit, use a larger battery, and use the traction motor to its full potential. unfortunately, toyota has never had the balls to do this. every hybrid has had a small battery and relied too much on the ICE for power. on the other hand, GM and the volt refuse to use the ICE for motive power. combine these two designs and you get one helluva hybrid system imo.

[serialk11r]

Originally Posted by madfast

huh? toyota has used the eCVT for years. and i think the LS600h with 438 hp has enough hp to be considered high power. in fact the only reason why HSD hybrids are not more powerful is that they have a small battery. they use an "oversized" motor for the regen, not for motive power. so one can see if they wanted to, they could easily tweak the HSD system a bit, use a larger battery, and use the traction motor to its full potential.

These all cost big money though. LS600h is what, 45k more expensive than the LS430, and it has the same gasoline engine? Of course there are profit margins in there but you get the point.

Toyota has used the eCVT for years, but anything with an eCVT in it has costed a pretty penny. For the puny 2ZR/1NZ FXE engines sure it works and the price of those cars is affordable, but for more powerful engines you have a proportionally higher cost in power electronics, motors, etc.

Certainly, with more advanced energy storage they could squeeze more power out. But you can do the same thing with a single motor attached to the crankshaft. With high voltages, motors can keep on making power at higher rpm.

[S2kphile]

The more I keep looking at the RX concept the more I think of this characterture

[madfast]

Originally Posted by serialk11r

These all cost big money though. LS600h is what, 45k more expensive than the LS430, and it has the same gasoline engine? Of course there are profit margins in there but you get the point.

well that's not exactly fair being that the LS600h is the highest trim of the LS family. and the hybrid uses the 5.0L V8 not the 4.6L. a better comparison is the GS. the GS450h is "only" about 12k more expensive however the hybrid is also the highest trim of the GS family...

Toyota has used the eCVT for years, but anything with an eCVT in it has costed a pretty penny. For the puny 2ZR/1NZ FXE engines sure it works and the price of those cars is affordable, but for more powerful engines you have a proportionally higher cost in power electronics, motors, etc.

what hybrid hasnt been expensive? but that isnt a big deal anyways. toyota's HSD has proven its worth from a design perspective and it hasnt even been used in a real sports car yet.

Certainly, with more advanced energy storage they could squeeze more power out. But you can do the same thing with a single motor attached to the crankshaft. With high voltages, motors can keep on making power at higher rpm.

e-assist? it will never compare in terms of power and fuel economy. its only advantage is cost.

[madfast]

what we havent seen from any manufacturer yet is a hybrid system that uses the electric motor as its main propulsion, with the ICE as an assist. the closest design is the Voltec system where above ~70 mph, the ICE assists in turning the wheels, but that's for efficiency reasons, not sporting ones. using the same Voltec design, they can easily use a powerful ICE and assist the electric motor at any speed if they wanted to. its a beautiful system that has so much potential.

being that HSD is also planetary gearset based, toyota can easily make some tweaks and emulate the capabilities of Voltec. at the least they can use a dedicated hybrid/EV chassis with the battery as a stressed member in the floor like the tesla model s. then with the larger battery pack, they can have a much more capable EV mode.

[serialk11r]

Originally Posted by madfast

what hybrid hasnt been expensive? but that isnt a big deal anyways. toyota's HSD has proven its worth from a design perspective and it hasnt even been used in a real sports car yet.

e-assist? it will never compare in terms of power and fuel economy. its only advantage is cost.

Honda IMA carries a lower price tag than HSD, though it's undoubtedly inferior.

Power or fuel economy, I dunno about "never compare". Low load operating efficiency has a long way to go on most engines, hybrids will see less and less of a fuel economy benefit as manufacturers improve their engines. Where hybrids can really shine is very low speeds, but most driving doesn't happen at low speeds. Using the electric motors and power electronics to transfer power has its own efficiency penalty anyways, it's not a perfect solution.

[madfast]

Originally Posted by serialk11r

Honda IMA carries a lower price tag than HSD, though it's undoubtedly inferior.

Power or fuel economy, I dunno about "never compare". Low load operating efficiency has a long way to go on most engines, hybrids will see less and less of a fuel economy benefit as manufacturers improve their engines. Where hybrids can really shine is very low speeds, but most driving doesn't happen at low speeds. Using the electric motors and power electronics to transfer power has its own efficiency penalty anyways, it's not a perfect solution.

honda's IMA and the ubiquitous ZF hybrids are all stopgap solutions imo. they are nowhere near as, advanced if you will, as HSD and Voltec. Honda's new accord plug-in however is a step in the right direction. still not as capable as Voltec, but much simpler and probably cheaper. way better than the prius plug-in, but that's not a real plug-in effort by toyota anyways.

i agree there can be much more improvement in low load operation for the ICE, however im talking about sports cars. low load conditions arent fun. i want as high mpg as possible, while still going as fast as possible. i cannot see the ICE ever beating a hybrid system in terms of performance and mpg in all road conditions at all speeds. there is way more upside with hybrids than with the ICE. imo battery tech alone will make hybrids the standard in the very near future...

[serialk11r]

iono personally I want (>=)3 pedals and a gear change lever, and the only way to do that without getting ridiculous is electric assist. I'm pretty sure if you modify DFCO to have throttle fully open, or have an exhaust DFCO valve, along with all electric accessories, you can cut the engine's braking effect by over 60% or more. The regeneration capabilities of even the Toyota hybrids are limited considering that friction brakes can dissipate energy at the rate that the fastest supercar engines can produce it, and the "regeneration power" of an electric motor is typically a lot lower than its rated power.

So the deal is, even if we put immensely powerful motors on the front wheels, there's no way we can get close to full brake regeneration capability. In day to day driving, having more is better since we don't need to slow down as quickly, but if you don't have variable speed drive for the electric motor then you can't really regenerate power very well either. At low speeds, HSD can barely recover any energy at all. But take an IMA system with a matching size motor, downshift to first gear, and you'll be able to spin the electric motor faster. I may have remembered something incorrectly about HSD but I am fairly sure in this scenario you can get better regen from a mild hybrid system with equivalent motor size. Under heavy braking, the HSD and fantasy IMA will have similar capabilities, and under light braking from high speed HSD dominates, but if you're slowing down from high speed you can bleed off quite a bit of speed just coasting down, which is more efficient anyways.

[midenginebias]

Originally Posted by HunterGreene

I don't know why some of you guys are so turned off by hybrids. From an engineering perspective, they work, and can outperform traditional gasoline/petrol driven cars in some cases. The immediate torque of an electric engine is nothing to sneeze at, and if you couple it with a rotary engine, you may have a bit of a beast on your hands.

If the complaints are due to the fact that the batteries of a hybrid kill the car's ability to handle or accelerate, why is the Fisker Karma, albeit overpriced, still a decent-handling and accelerating machine?

Why the hate? Not all the hybrids out there are Priuses.

It's not an elegant solution. It's expensive. I don't even want to think about the oil/transportation/exported costs into building a hybrid in the first place.

There are FAR more fuel efficient diesels in the U.K.

Mazda is implementing Skyactiv technology in both petrol AND diesel configurations.

Subaru has a boxer diesel 2.0, which has 150hp, 258lb ft., 42mpg (US)

Ferrari and Porsche are implementing hybrids, yes, but utilizing the electricity as either HP boost or pure electric range extenders.

Elegant solution? Hydrogen. Most abundant resource. Honda Clarity roughly has 130hp 180lb ft, on 60mi/compressed gallon.

[HunterGreene]

Originally Posted by midenginebias

It's not an elegant solution. It's expensive. I don't even want to think about the oil/transportation/exported costs into building a hybrid in the first place.

There are FAR more fuel efficient diesels in the U.K.

Mazda is implementing Skyactiv technology in both petrol AND diesel configurations.

Subaru has a boxer diesel 2.0, which has 150hp, 258lb ft., 42mpg (US)

Ferrari and Porsche are implementing hybrids, yes, but utilizing the electricity as either HP boost or pure electric range extenders.

Elegant solution? Hydrogen. Most abundant resource. Honda Clarity roughly has 130hp 180lb ft, on 60mi/compressed gallon.

You are absolutely correct on all points (especially the costs to build a hybrid, it makes me laugh), but at no point did I call it an elegant solution. Remember, all technology is expensive when it first comes out, hybrid/fuel cell electrics are no exception.

A couple of your points, however--the technology relies on petroleum based products, which will eventually become so hard to find and process that we will HAVE to switch to something else. Hybrids are a baby step in the right direction, with the true endgame here being hydrogen driven (fuel cell) electrics. My only hope with that, however, is the cost of oil spiraling out of control and forcing the current technology to evolve and the automakers innovate to make it a reality.

[midenginebias]

Originally Posted by HunterGreene

You are absolutely correct on all points (especially the costs to build a hybrid, it makes me laugh), but at no point did I call it an elegant solution. Remember, all technology is expensive when it first comes out, hybrid/fuel cell electrics are no exception.

A couple of your points, however--the technology relies on petroleum based products, which will eventually become so hard to find and process that we will HAVE to switch to something else. Hybrids are a baby step in the right direction, with the true endgame here being hydrogen driven (fuel cell) electrics. My only hope with that, however, is the cost of oil spiraling out of control and forcing the current technology to evolve and the automakers innovate to make it a reality.

I'm under the impression that hybrids are just a stop-gap until other technologies catch up.

In regards to alternative fuel usage in the marketplace, I am a bit frustrated. Biodiesel. Biofuel. Hydrogen. Not enough infrastructure, increasing costs of corn (or transportation and outsourced work for hybrid), and yet, the technology is currently available for an alternative fuel car to drive like a normal compact/midsize sedan right now.

Coming from my part of So Cal, knowing it would be expensive, I wish I could create my own alternative fueling station. Hydrogen, biofuel, biodiesel, pure pump gas, race gas, and a 220v station, while being near a movie theater or mall. There is customer volume to be had, granted it isn't high volume, but at least it makes sense for the local population within a 50mi. radius.

[WingsofWar]

wireless ultracapacitor road charging..fuck batteries and regen systems

[HunterGreene]

Originally Posted by WingsofWar

wireless ultracapacitor road charging..fuck batteries and regen systems

Nothing like a nice Monday morning laugh. I miss this game.