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Audi e-tron
Concept has four electric motors and a single battery pack

The world of electric and hybrid vehicles is progressing and growing at a rapid pace. While most people still think of hybrids and electric vehicles as low performance machines, there are an increasing number of high-performance electric vehicles being unveiled.

The first high performance EV was the Tesla Roadster with good performance thanks to the impressive torque of the electric motor. Audio has unveiled its latest concept car at the International Motor Show in Frankfurt called the Audi e-tron which just so happens to look like an electrified Audi R8.

The most impressive feature of the concept isn’t just its all-electric power train, but its tremendous amount of torque. Audi claims that the e-tron has a torque rating of  3,319.03 lb-ft. All that torque is generated by four individual electric motors situated at each wheel allowing the vehicle to be all-wheel drive.

The car has a total of 313 HP and promises to hit 60 mph in about 4.8 seconds. A more impressive number is that the car can go from about 37 mph to 74 mph in only 4.1 seconds. The all-electric range for the lithium-ion battery pack is 154 miles.

The EV is a large beast at 3,527 pounds and it measures in at 74.5-inches wide x 167.72-inches long and 48.43-inches tall with a wheelbase of 102.36-inches. The massive single battery pack alone weighs 1,036 pounds.

"We are trying to find a concept that requires no compromises," says Michael Dick, Member of the Board of Management of AUDI AG, Technical Development. "Electromobility means more to us than just electrifying conventional cars. Instead, we are dedicated to a holistic approach to all aspects of the topic."

Audi's American President called potential Volt buyers idiots not long ago and then quickly claimed he forgot what he said. There was only speculation surrounding the Audio EV concept at the time the comments were made.



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RE: <Drool>
By Spuke on 9/15/2009 11:46:54 AM , Rating: 2
quote:
3,000 ft-lbs of torque is useless in a sports car. How do you couple it to the road?
With todays tires, you don't. The torque would be severely limited in reality. BTW, I heard rumors of this car for the past two months or so. The rumors were an actual electric R8. But it turns out it's just a concept car with an R8-like body.


RE: <Drool>
By theapparition on 9/15/2009 3:16:32 PM , Rating: 4
Not at all true.

Take an old C5 Corvette, with only approximately 360ft-lbs. Multiply that by 3.06 for first gear and 3.42 for differential gear. That's a torque multiplier of 10.46 which is a total of ~3800ft-lbs at the rear wheels.

Not at all much different. Also explains why 0-60 times are so similar to a C5. A C6 would even be higher in the 4500ft-lbs range.

Quite a bit of difference between engine torque and wheel torque.


RE: <Drool>
By Spuke on 9/16/2009 11:38:06 AM , Rating: 3
quote:
Quite a bit of difference between engine torque and wheel torque.
Then what does a Dynojet measure?


RE: <Drool>
By theapparition on 9/16/2009 12:57:10 PM , Rating: 2
Have you ever run a Dynojet?

I have.

You have to enter those parameters in when stating the pull. For automatics, it uses the ODB port to determine which gear you're in.

When an engine is rated for torque and power, per the SAE standard, it is tested on an engine stand, not in a car.

It is a misnomer that when gearheads (like myself) rate cars with rwhp and rwtq, it is really engine hp and torque accounting for drivetrain losses.


RE: <Drool>
By Zoomer on 9/16/2009 6:30:23 PM , Rating: 2
Since the motors are at the wheels with no drivetrain, wouldn't engine torque = wheel torque?


RE: <Drool>
By theapparition on 9/17/2009 7:45:38 AM , Rating: 2
No. The wheel torque in a car with an ICE will be approximately 10x that of the engine itself. (All depends on the gearing in the transmission and differential, but 10x is decent 1st gear average.)

Wheel torque in a car with a motor mounted in the hub will be equal to the torque rating of the motor.

They are making this out to sound like something special, when it's really not. Where it does differ is the motors delivery of torque. Full torque is available at almost 0 RPM, while an ICE reaches max torque at a much higher RPM. That is why it is essential to drop the clutch (or use a high stalled auto) at the RPM where most torque is delivered for the best launch.


RE: <Drool>
By Spuke on 9/17/2009 1:31:20 PM , Rating: 2
quote:
Have you ever run a Dynojet?
I have not but that's why I'm asking. When you get a graph from a dyno, the torque rating isn't 4500 lb-ft (or whatever ridiculously high number). Maybe this discussion of torque multiplication is confusing me but I always thought that the actual torque number when a car is dyno'd was the result of the gearbox multiplication. My car would make say 220 lb-ft at the wheels on a Dynojet not 3000 lb-ft.


RE: <Drool>
By theapparition on 9/17/2009 3:58:35 PM , Rating: 2
No. It measures that high number and then back-calculates through input parameters to determine theoretical engine torque.

That's why I stated before the the concept of rwtq is flawed, yet often quoted (hell, even by myself). Yet what is being delivered to the tires is quite different.

In fact, dynojets don't even measure the engine RPM on older cars, rather use the tire diameter and tire RPM to generate those graphs.

For a simple ballpark figure, take the engine power and divide it by tire RPM. Power = Torque * RPM/5252.

So if an engine is developing 300hp at 6000RPM, and there is a 10x reduction through gearing, than the torque being delivered is 300hp*5252*(6000RPM/10) = 2626ft-lbs.

Pretty simple, and also requires that a dynojet knows what size rear differential and what gear the car is being operated in. Otherwise the results are junk......and also how some unscrupulous tuners like to improve thier results.


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