Green GT's All-Electric Supercar Unveiled 196
Mike writes "Swiss auto company Green GT recently released the first details on a svelte all-electric supercar that is being heralded as the most powerful electric race car ever built. Designed with the 2011 Le Mans race in mind, the Twenty-4 will boast a sleek carbon fiber chassis and twin 100-kw electric motors totaling 400 hp — enough to push the vehicle from 0-60 mph in 4 seconds flat, and to a top speed of 171 mph. GreenGT's head engineer Christophe Schwartz has stated that 'The GreenGT Twenty-4 design study could become our 2011 Le Mans Prototype electric racer, or it could even become an electric road-going supercar. There is a possibility to do both!'"
Looks like PDX's Plasma Boy Racing (Score:4, Informative)
Looks like Plasma Boy and his White Zombie [plasmaboyracing.com] have a competitor out there. (AFAIK, he uses hot-swappable battery packs as well, and only goes full out on the quarter mile).
2x100kW (Score:5, Informative)
2 x 100kW != 400 HP (Score:2, Informative)
Subject says it all, well almost.
100kW == 134HP
2 x100KW != 400HP (Score:3, Informative)
200KW ~= 268HP
400HP equivalent?
They need to explain that a bit better in the article and on the product website [green-gt.com]
Jack Bauer (Score:3, Informative)
Re:2x100kW (Score:4, Informative)
It looks like a bad Google translation. The original French:
2 moteurs triphasés synchrones de 2 x 100 kW linéaires (2 synchronous tri-phase motors, each 2x100kW linear)
The Google translation:
2-phase synchronous motors of 100 kilowatts x 2 linear
Re:Heat Problems? (Score:4, Informative)
You hit it, the cooling is for breaks and tires, as well as down pressure.
Every once and a while in the NASCAR races they'll show you a camera view from inside the wheel well. You can see when the driver hits the breaks the rotors literally become red-hot from the friction of trying to slow the car down.
Now imagine that same situation, with wider tires and faster speeds on tracks with significantly more braking.
Odds are though, that the frame they are starting with is from some company that produces frames for indy or some other circuit cars. Just as the Tesla Roadster is actually a Lotus frame and body. So the cooling requirements will likely vary significantly from the function of the imaged vehicle.
-Rick
Re:24 hour charge?? (Score:5, Informative)
Re:24 hour charge?? (Score:4, Informative)
Even racing supercars don't come close to running at 100% throttle nonstop -- and when they do slow down for turns, regen puts power back into the pack. Li-ion regen in the Roadster, for example, is around 65-70% efficient if I recall the numbers correctly. So you only lose 30-35% of the energy expended on an accel/decel cycle; the rest of your losses are primarily aero and rolling. Aero, which should be the primary loss mechanism, will depend heavily on how much downforce there is.
I agree, though, in that it's probably not practical for the race unless the pit stops are long.
Re:2x100kW (Score:5, Informative)
There is no actual conversion from kW to hp
Yes there are, but it's highly dependent on the context in which you use the term horsepower since it's not an SI unit.
One mechanical horsepower of 550 foot-pounds per second is equivalent to 745.7 watts
A metric horsepower of 75 kgf-m per second is equivalent to 735.499 watts
A boiler horsepower is used for rating steam boilers and is equivalent to 34.5 pounds of water evaporated per hour at 212 degrees Fahrenheit, or 9809.5 watts
One horsepower for rating electric motors is equal to 746 watts
http://en.wikipedia.org/wiki/Horsepower [wikipedia.org]
Re:24 hour charge?? (Score:3, Informative)
well, it doesn't have to run for 24 hours on one charge, the other race cars are lucky to run 70 minutes on a tank of gas...
If it can make 150 miles, when they pull in to swap the tires, and jack it up, they could also drip the batteries from the under carrige and replace them en masse.
high performance charging system run on generators pit-site could bring those Li-Ti or Li-Su batteries to full charge in 30 minutes...
My concern is the 400HP total... most of it;s competition does 0-100 in about 8 seconds, and runs in the 600-1000HP range... For instance, the Audi Deisel (first time ever) ran at 650HP http://www.auto-power-girl.com/specifications/audi/audi_r10_le_mans_race_car-540 [auto-power-girl.com]
Heck, the "lemans edition" steet cars sold as production vehicles very often peak over 500HP... and those are not the race models, but simply collector cars.
Re:settled by Wolfram (Score:5, Informative)
hp = ft * lbs / min
W = N * m / sec
All of these units convert directly. I call your Wolfram and raise you a Google [google.co.uk].
Re:24 hour charge?? (Score:5, Informative)
This is how it was done in SAE formula lightning. [wikipedia.org]
There is a video of the WVU team doing a pit practice here [youtube.com]. These are college kids, probably engineers and not mechanics. A real pit crew could do it in much less time.
Re:slow (Score:3, Informative)
The acceleration is fine; most supercars do not have the best possible acceleration because it would interfere with top speed (e.g. gearing issues.) The top speed, however, is less than 200 mph, which is pretty much mandatory for a supercar today.
They need at least 800hp..... (Score:2, Informative)
2) There currently is NO electric car class at all
3) LeMans is by "Invitation only", not just anyone can show up and race.
~2008 specs for the front runners:
Audi R10: 650 hp-1100 Nm-925 kg
Peugeot 908: 700 hp-1200 Nm-925 kg
171? (Score:3, Informative)
Re:2x100kW (Score:3, Informative)
Re:Racecars? (Score:2, Informative)
Fastest? (Score:2, Informative)
"...the most powerful electric race car ever built."
Maybe for a certain class of race car, but The Buckeye Bullet [buckeyebullet.com] broke 300 mph years ago, and the new model will have been tested before this Green GT car is built.
Re:24 hour charge?? (Score:4, Informative)
Re:That's still a lot of power... (Score:4, Informative)
Fail.
Re:24 hour charge?? (Score:2, Informative)
While they talk about recharging the car between races, there is a diagram on their website http://www.green-gt.com/index.htm [green-gt.com] that illustrates that they will be using Hydrogen to store the energy and using fuel cells to generate electricity.
Re:24 hour charge?? (Score:5, Informative)
Ahhh grasshopper. You are confusing horsepower with torque. A diesel engine with 100hp can create hundreds of pounds of torque. Horsepower doesn't tell the whole story and is not representative of how much torque the engine can produce, which varies with engine speed. A typical car has a torque curve that starts out gradually climbing and then reaching its maximum around 3000-4000 rpm (just an example here people) and begins to flatten and decline towards the red line, say at 6000 RPM. That means that this engine is only outputting peak torque at the maximum point in the curve. An electric engine has a purely linear torque scale. At 1 RPM it is generating 500lbs of torque. At 6000 RPM it is generating 500lbs of torque.
"The torque of an electric motor is independent of speed. It is rather a function of flux and armature current." - Wiki
Coupled with a continuously variable transmission (ala Prius) electric engines are both highly efficient and insanely powerful. If we can get past the hurdles of energy storage, which clearly dominates this discussion, then internal combustion engines will start to look as antique as the coal fired steam engine. I mean seriously. Which is more elegant, a giant motor, a shaft of metal surrounded by magnets and a coil of wire which is like 95% efficient or an insanely complex machine made of thousands of moving parts and components, which including a whole lot of small motors is only like 23% efficient at best? Never mind all the crap you had to go through to get the fuel that only yields 23% efficiency. Oh and forget about the terribly messy process of getting some black tar that was supposed to probably stay in the ground for a few million more years to cook down and refine into gasoline. (And people wonder why they haven't been building new refineries in the United States, maybe those people should have one in their backyard) I mean geez, solar panels are starting to exceed those kind of numbers already.... To hell with spending money on how to suck out the last few drops of oil from some sandy shoals. We should be spending all of our money on figuring out how to cleanly produce electricity. Our very future depends upon it in more ways than one.
Hmmmmmm....now where do we have a huge source of energy close by?
Re:24 hour charge?? (Score:3, Informative)
Most Formula 1 and Le Manns cars utilize Bernoulli tunnels under the car to produce significant downforce.
Re:24 hour charge?? (Score:2, Informative)