Are cars like the Tesla Model S the future?

[racerboy71]

hey canndo, what are your thoughts on kers, kinetic energy recovery systems, currently being used in formula one if you're at all familiar with them..

 

[Dr Kynes]

What you are talking about is transmissions - the use of gearing ratios to keep internal combustion engines within optimal power bands. Did you believe that no electric vehicles had similar trains? Once a vehicle is under speed then it is no longer expending energy to accelerate but mearly needs to overcome road and wind reistance.

I'd like to see your source for "electric motors are less efficient than internal combustion engines. The figures I gave, regardless of your point, make up for those differences. Even if an internal combustion engine is at it's most efficient in a given situation it cannot compare to an electric - in any situation. This is simply physics. Where the energy it took to bring an electric car from a full stop to 60 mp to continue at that rate, the vehicle would continue to attempt to accellerate until inertia and resistancefinally limited that increase in speed. Thus, one naturaly lets off on the pedal, in so doing, offering that motor lessenergy. Let alone the possible inclusion of transmission gear boxes.

i didnt make the laws of physics. i just adhere to them.

if you can develop an electric motor that delivers load and speed senistive power across a wide range of speeds, and can throttle back for efficient cruising operation then patent it.


youll make a mint.

ill buy one.

 

[Beefbisquit]

i didnt make the laws of physics. i just adhere to them.

if you can develop an electric motor that delivers load and speed senistive power across a wide range of speeds, and can throttle back for efficient cruising operation then patent it.


youll make a mint.

ill buy one.

Neener neener.

http://www.gizmag.com/antonov-3-speed-transmission-ev/19088/

A guy actually already made a 3 speed EV transmission. The first testing showed a 15% increase in efficiency over the standard EV gearing with no power drop. Pretty neat really!

Also says it can be modified to make a 4 speed transmission, which in turn would be even more efficient.

 

[Dr Kynes]

Neener neener.

http://www.gizmag.com/antonov-3-speed-transmission-ev/19088/

A guy actually already made a 3 speed EV transmission. The first testing showed a 15% increase in efficiency over the standard EV gearing with no power drop. Pretty neat really!

Also says it can be modified to make a 4 speed transmission, which in turn would be even more efficient.

a transmission and gearing to reduce the shortcomings of electric motors is not a solution, it's a bandaid.

Protip: transmissions are also used to overcome the shortcomings in combustion engines too. it doesnt alter the nature of their operation, or change their real power output characteristics.

 

[cannabineer]

WRONG AGAIN.

electric motors are more efficient only at delivering torque to get up to speed. once they are AT SPEED they consume just as much energy to maintain that speed as they do accelerating against inertia to acheive speed, while a combustion engine is most efficient at steady throttle cruise.

dont even try to argue otherwise, because youre just plain wrong.

you are arguing total efficiency, measured in joules, energy in, vs energy out, which is great in a laboratory, but SUCKS when you need to do actual work.

What militates against this is the overall goodness of a real-world engineering solution: the Diesel-electric rail locomotive. It combines the best features of internal combustion (high energy density) with electric drive (excellent power delivery across a broad demand spectrum), and the electric portion allows the IC motor to run in its best spot on the BSFC graph. Brake specific fuel consumption is the measure of how much energy is being extracted from a given mass of fuel consumed. (in auto engines, the BSFC optimum is typically at almost-open throttle at low rpm.)

 

[Dr Kynes]

What militates against this is the overall goodness of a real-world engineering solution: the Diesel-electric rail locomotive. It combines the best features of internal combustion (high energy density) with electric drive (excellent power delivery across a broad demand spectrum), and the electric portion allows the IC motor to run in its best spot on the BSFC graph. Brake specific fuel consumption is the measure of how much energy is being extracted from a given mass of fuel consumed. (in auto engines, the BSFC optimum is typically at almost-open throttle at low rpm.)

thats an excellent example of a hybrid, the current best choice for efficiency, using the diesel to cruise, and the electric to supplement at acceleration, and braking

funny how theres no magic flywheels or eldritch magnets.

i am amazed there havent been any Zero Point Energy or "THEY dont want you to know" comments

the lodestone mag-lev stuff was lulzy as shit.

 

[twostrokenut]

Diesel-electric locomotive model transferred to an automobile, more efficient than gas or electric alone?
Am I correct in understanding this to only have one drive, ahem, train?

 

[SirGreenThumb]

Back in 2010 my fiancee invested 1900 dollars for 100 shares @ $19.00 in tesla. it is now @ 145.72 a share. I have to say i thought it was a bad idea at the time as i didn't think it would take off because of how much it cost to buy. i was wrong.

 

[Canna Sylvan]

thats an excellent example of a hybrid, the current best choice for efficiency, using the diesel to cruise, and the electric to supplement at acceleration, and braking

funny how theres no magic flywheels or eldritch magnets.

i am amazed there havent been any Zero Point Energy or "THEY dont want you to know" comments

the lodestone mag-lev stuff was lulzy as shit.

The new NSX coming out next year will do just that.

 

[twostrokenut]

Nsx was a sexy biatch that's good news.

 

[cannabineer]

thats an excellent example of a hybrid, the current best choice for efficiency, using the diesel to cruise, and the electric to supplement at acceleration, and braking

funny how theres no magic flywheels or eldritch magnets.

i am amazed there havent been any Zero Point Energy or "THEY dont want you to know" comments

the lodestone mag-lev stuff was lulzy as shit.

The thing though is that only the electrics drive the wheels. So if, as you claim, electromotors suuck at steady demand, the diesel-electric loc should be a less-than-viable proposition. the diesel motor is never coupled to the drive wheels.

A bonus of the electric system is that the drive motors can be used for inductive/resistive (dynamic) braking. Those fans on top extract heat energy from some serious power resistors (grids), essentially heating elements that can dissipate up to 100kW each. Cool Youtube vids of locs blowing dynamic braking grids exist.

 

[Canna Sylvan]

Nsx was a sexy biatch that's good news.

You have $110k?

 

[twostrokenut]

You have $110k?

Ummm No.

Victorias secret models are sexy too and I can't afford one of those either.

 

[canndo]

no.

torque is the force impulse against inertia.

horsepower is a result of torque and speed together, measured at the output in work accomplished.

some engines deliver so much torque that they can make the car rock when you ramp on the gas with the clutch in, but thats a result of massive fuel consumption, 90% or better volumetric efficiency, high compression ratios and usually a supercharger.

electric motors of a similar size and power output can do that job MUCH better, since the go from zero to MAXIMUM POWER in the blink of an eye while a combustion engine has to climb up to it's best torque range.

but electric motors are always operating at MAXIMUM POWER from the moment you close the circuit till you open it up gain.

you ever popped the clutch when your starter motor is working? the whole car lurches forward then stops because the motor has been defeated.

if you turn over the starter again youll feel it lurch again then stop because it does not have the ability to throttle up, and thus is defeated by inertia.

if your electric motor and batteries were powerful enough to move the car, you would get moving quite rapidly, even faster than you can with a gas engine, but once you hit the motors' speed, thats it. and whether you are going from a stop to cruising, or cruising for an hour, electric motors use the same amount of power all the time when they are in operation.

imagine your power drill. it goes from stopped to cranking that screw quicker than shit, but when the screw bottoms out, the drill just stops. no amount of jamming on the button will make it use more power or less (variable speed drills use a resistor to simulate a throttle but i tcan only apply downward pressure on the motor's speed)

a combustion engine, once in motion, uses FAR less juice than it does to accelerate up to speed. once it is going, it keeps going with much less input, but electric motors always use the same amount of energy to operate whether they are facing huge resistance (inertia, hills or friction) or no resistance at all.

when a combustion engine is running at speed, it breathes deeper, drawing more fuel and air in, and as that speed increase so does it's efficiency, until it hits the top of it's power curve, and then the efficiency starts to drop. (usually the spot on your speedometer occupying the vertical position is the optimum speed in top gear) this range offers the most efficient power to fuel consumption ration yet devised. this is why they are so effective.

electric motors may in fact have a better ratio of power in to power out, but that only matters in a laboratory.

You are going to have to explain to me how a reostat works then. Limiting the MAXIMUM electrical power to a motor will allow that motor only to drive at the MAXIMUM power range that it is capable of at that inflow of power. Thus, although you may be right, that an electric motor only operates on full off or full on, if full on is only 50 percent of deliverable energy then it will only deliver 50 percent of it's power. In that case, it is still more efficient than internal combustion engines and much more precise.

 

[Dr Kynes]

The thing though is that only the electrics drive the wheels. So if, as you claim, electromotors suuck at steady demand, the diesel-electric loc should be a less-than-viable proposition. the diesel motor is never coupled to the drive wheels.

A bonus of the electric system is that the drive motors can be used for inductive/resistive (dynamic) braking. Those fans on top extract heat energy from some serious power resistors (grids), essentially heating elements that can dissipate up to 100kW each. Cool Youtube vids of locs blowing dynamic braking grids exist.

electrical braking systems, and their energy reclamation is not at issue.

the electric motor draws power at a set rate, this rate is constant, while a combustion engine can run on a leaner mixture (less energy consumed per joule at the wheels) at cruising while an electric motor which draws 10 amps for X joules at the wheels will always draw 10 amps and deliver those same X joules at the wheels.

electric motors have the edge on efficiency at acceleration and in short bursts but combustion engines dominate over distance.

 

[canndo]

electrical braking systems, and their energy reclamation is not at issue.

the electric motor draws power at a set rate, this rate is constant, while a combustion engine can run on a leaner mixture (less energy consumed per joule at the wheels) at cruising while an electric motor which draws 10 amps for X joules at the wheels will always draw 10 amps and deliver those same X joules at the wheels.

electric motors have the edge on efficiency at acceleration and in short bursts but combustion engines dominate over distance.

You have still made not one mention of friction and heat - the electric motor producing far less waste energy in the form of heat and encountering far less friction.

 

[Dr Kynes]

You are going to have to explain to me how a reostat works then. Limiting the MAXIMUM electrical power to a motor will allow that motor only to drive at the MAXIMUM power range that it is capable of at that inflow of power. Thus, although you may be right, that an electric motor only operates on full off or full on, if full on is only 50 percent of deliverable energy then it will only deliver 50 percent of it's power. In that case, it is still more efficient than internal combustion engines and much more precise.

and combustion engines can run at a set speed with dramatically reduced fuel consumption while an electric motor always draws the same amount of energy to operate, and the load determines how fast it goes.

i got a 1/4 hp power drill. i can stop it from turning with my bare hands.

try and stop a 1/4 hp gasoline engine with your hands and youll get fucked up.

 

[canndo]

and combustion engines can run at a set speed with dramatically reduced fuel consumption while an electric motor always draws the same amount of energy to operate, and the load determines how fast it goes.

i got a 1/4 hp power drill. i can stop it from turning with my bare hands.

try and stop a 1/4 hp gasoline engine with your hands and youll get fucked up.

And I can stall a car by putting it in the wrong gear when I take off. The load decreases to that of friction in a moving car, thus, an electric car should continue to accelerate, it does not. one introduces less electricity into the mechanism - using less energy because the energy is now limited to the amount the driver supplies by virtue of his foot.

 

[Dr Kynes]

And I can stall a car by putting it in the wrong gear when I take off. The load decreases to that of friction in a moving car, thus, an electric car should continue to accelerate, it does not. one introduces less electricity into the mechanism - using less energy because the energy is now limited to the amount the driver supplies by virtue of his foot.

i am obviously not explaining this very well.

electric motors work good, within their range, with maximum torgue and power delivered when they go from a stop, to speed. like a power drill.

combustion engines deliver less power at the work face per fuel consumed at accelleration from (nearly) stopped to speed, but once they get up to speed they keep going with LESS power input to maintain that speed.

example: a gasoline auger.

they are a pain in the butt to get going, and once the engine is started, you have to give them lotsa gass to get the shaft cranking. however once you get the shaft going they keep going, boring a hole in the earth quite readily.
electric augers SUCK, they get going like a bat out of hell, but if you hit a decent sized rock, they can simply STOP DEAD, where a gasoline auger will tear that fucker loose and ramp it out of your hole.

cotroling an electric auger at startup is tough as shit, like rasslin an ornery animal, while the gasoline auger is slower to get up to speed, then it just goes to work.

this is why electrics work great for hydraulics (fast response, high torque impulse) but they pale in comparison to combustion engines for steady work. plus when you run out of juice you cant run back to the barn and grab a gallon can of electricity to get the job done...

 

[Beefbisquit]

http://www.topgear.com/uk/photos/jaguar-c-x75-top-gear-drive-2013-08-02

Some cool electric (and FI) tech in this car...