400lb of torque??

[evboy]

Can someone explain how the spark ev has about the same amount of torque as a porsche. I know electric doesnt waste power like gas but the leaf doesnt get that amount of torque or the other small electric cars. is the car really light compared to the fit and leaf. what gives.

 

[TomT]

Maybe it is like they rate some 2000 watt audio amplifiers and 5 horsepower vacuum cleaners: Peak, instantaneous, incredibly-short-term, power... :lol:

Can someone explain how the spark ev has about the same amount of torque as a porsche. I know electric doesnt waste power like gas but the leaf doesnt get that amount of torque or the other small electric cars. is the car really light compared to the fit and leaf. what gives.

 

[Deleted member 9549]

Can someone explain how the spark ev has about the same amount of torque as a porsche. I know electric doesnt waste power like gas but the leaf doesnt get that amount of torque or the other small electric cars. is the car really light compared to the fit and leaf. what gives.

Torque is determined by the base torque design of the electric motor, ie number of windings, by the gearing ratio between the electric motor and the wheels, and by the amount of power that can be delivered to the motor. The power is based on the voltage of the pack and maximum amperage.
All electric vehicles tend to have high torque from a start. Higher than most ICE vehicles especially from a start.
Its not hard to get higher torque in an electric vehicle but it has tradeoffs regarding cost, efficiency through the speed range, battery life etc.

 

[LKK]

Here is a post made by a GM engineer on this subject on insideevs:

"
Peter Savagian
May 1, 2013 at 12:21 pm
I am the general director for Electric Drives and Electrification Systems Engineering at General Motors. I need to disabuse you of the mistaken notion that this motor has less than 400 ftlb of Torque. The Spark EV motor is designed and manufactured by GM. This motor makes 540 Nm (402 ftlbf) of Torque at stall and out to about 2000 rpm. This is not gear- multiplied axle torque, but actual motor shaft torque.
The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two). This is a very low numerical reduction ratio, which has several great benefits – 1) Feels much better to drive. 3.18:1 is less than half of the reduction of all other EVs. This makes for extraordinarly low driveline inertia, less than 1/5 of the driveline inertia of the Nissan Leaf and 1/4 that of the Fiat 500 EV. Their cars feel like you are driving around in second gear all day long; ours feels like fourth gear. 2) Lower gear mesh, spinning losses, and lower high speed electromagnetic losses mean very high drive unit efficiency. The Spark EV efficiency from DC current to delivered Wheel torque is 85% averaged over the city driving schedule and 92% when averaged over the highway schedule. This is the highest in the industry, and that is one of the reasons why the Spark EV sets the benchmark for most efficient car."

 

[jhm614]

Here is a post made by a GM engineer on this subject on insideevs:
"
Peter Savagian
May 1, 2013 at 12:21 pm
I am the general director for Electric Drives and Electrification Systems Engineering at General Motors. I need to disabuse you of the mistaken notion that this motor has less than 400 ftlb of Torque. The Spark EV motor is designed and manufactured by GM. This motor makes 540 Nm (402 ftlbf) of Torque at stall and out to about 2000 rpm. This is not gear- multiplied axle torque, but actual motor shaft torque.

Interesting. I had assumed that the Spark had some type of unique transmission / reduction gear setup to hit the 400 ftlb of Torque. Does the Volt have similar performance? If not, I wonder if this motor will find its way into Voltec 2.0?

 

[evboy]

interesting read. i thought all the ev's had access to the same electric motor. looks like gm spent some real money on their R and D. well, when they say electric cars are going to keep getting better every year. this is proof. 2011 leaf compared to the 2014 spark ev is not even close in technology and quality.

 

[TonyWilliams]

interesting read. i thought all the ev's had access to the same electric motor. looks like gm spent some real money on their R and D. well, when they say electric cars are going to keep getting better every year. this is proof. 2011 leaf compared to the 2014 spark ev is not even close in technology and quality.

Ummm, yawn, ya, that Spark EV is just too far advanced (it looks like the marketing money was well spent!!!).

It's a teeny tiny car compared to the LEAF, and does accelerate quicker. The range is equivalent, with both cars in the 80 mile range with 100% charge on the EPA five cycle test.

The LEAF holds 5 people, Spark 4. The LEAF can hold a huge amount more cargo. LEAF has quick charge capability with almost 3000 worldwide charging stations; Spark EV currently has no quick charge capability nor are there deployed public chargers.

LEAF is the best selling street legal EV in the world with almost 70,000 sold. Spark EV plans to meet California compliance with 2500-ish to be sold here for 2012-2014 model years, plus whatever scraps they can find elsewhere (like Oregon).

 

[evboy]

the spark is a faster car and has a liquid cooled battery, so you wont have to worry about your battery being shot in 4 years. its also cheaper. no quick charger is a minus, but i rather have a liquid cooled battery pack for the money they would have spent on the QC. looks like we are heading in the right direction. i say gas cars are going to see their demise sooner rather then later.

 

[EVDRIVER]

interesting read. i thought all the ev's had access to the same electric motor. looks like gm spent some real money on their R and D. well, when they say electric cars are going to keep getting better every year. this is proof. 2011 leaf compared to the 2014 spark ev is not even close in technology and quality.

Ummm, yawn, ya, that Spark EV is just too far advanced (it looks like the marketing money was well spent!!!).

It's a teeny tiny car compared to the LEAF, and does accelerate quicker. The range is equivalent, with both cars in the 80 mile range with 100% charge on the EPA five cycle test.

The LEAF holds 5 people, Spark 4. The LEAF can hold a huge amount more cargo. LEAF has quick charge capability with almost 3000 worldwide charging stations; Spark EV currently has no quick charge capability nor are there deployed public chargers.

LEAF is the best selling street legal EV in the world with almost 70,000 sold. Spark EV plans to meet California compliance with 2500-ish to be sold here for 2012-2014 model years, plus whatever scraps they can find elsewhere (like Oregon).

I would still rather have that motor!

 

[TonyWilliams]

the spark is a faster car and has a liquid cooled battery, so you wont have to worry about your battery being shot in 4 years. its also cheaper. no quick charger is a minus, but i rather have a liquid cooled battery pack for the money they would have spent on the QC. looks like we are heading in the right direction. i say gas cars are going to see their demise sooner rather then later.

Yes, gasoline days are numbered, one way or another.

Liquid cooling and heating is only beneficial in hot or cold areas... Seattle does really need it, for instance. But, yes, overall the lack of cooling and heating of the pack is a detriment for most who drive the LEAF.

 

[SanDust]

Interesting. I had assumed that the Spark had some type of unique transmission / reduction gear setup to hit the 400 ftlb of Torque. Does the Volt have similar performance? If not, I wonder if this motor will find its way into Voltec 2.0?

Insightful. The Spark is light years ahead of the Leaf. Hopefully Nissan is paying attention. It's also completely different than the Volt.

The problem for EVs is that up to now fixed reduction gears have significantly compromised performance. You have to pick where in the speed range you want performance. The Volt addressed this problem with an electric transmission that uses a planetary gearset and two motors. The wheels are connected to the planetary carrier. At lower load the small motor drives the ring gear, which is larger than the planetary gear and hence more efficient. At higher loads (aka when you need acceleration) the large motor drives the sun gear, which is a smaller gear than the planetary carrier. That's actually very efficient but has the disadvantage of being expensive.

The Spark uses a different approach. It couples a very high torque motor with a lower ratio fixed gear. This gives you great performance across all speed ranges at a cost similar to what you see in the fixed gearing of the Leaf. Just for comparison, the Leaf uses an 8:1 reduction gear while the Spark uses 3:1. IIRC the Volt uses something like 6:1. (You can make up for a higher reduction gear with a larger motor but that's expensive also). That kind of difference is a big deal.

The question of whether GM will scrap the planetary gearset for the high torque motor setup in the Spark is a good one. I think they could significantly reduce the price of the car if they did.

 

[KeiJidosha]

“The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two).”

Spark EV - 402FtLb torque thru 3.18:1 drive = 1,278FtLbs axle torque
Fit EV - 189FtLb torque thru 8.05:1 drive = 1521FtLbs axle torque
LEAF - 207FtLb torque thru 7.94:1 drive – 1,643FtLbs axle torque

And Spark EV torque is flat to 2,000 RPM which is ~41mph. I have driven the Spark EV, Fiat 500e, LEAF, and have a Fit EV. Spark feels similar to Fit EV in Sport, but feels to sustain peak acceleration longer for a faster 0-60 time. While the motor torque number is stand-out, actual performance will be modestly better.
All are worthy of your consideration. LEAF has more room, Spark EV is quicker, 500e more style. LEAF lacks thermal management, 500e lacks QC, Spark EV has a slow on-board charger. RAV4EV beats all the above at higher cost. Availability, and your personal needs will determine which is a better buy.

 

[SanDust]

And Spark EV torque is flat to 2,000 RPM which is ~41mph. I have driven the Spark EV, Fiat 500e, LEAF, and have a Fit EV. Spark feels similar to Fit EV in Sport, but feels to sustain peak acceleration longer for a faster 0-60 time. While the motor torque number is stand-out, actual performance will be modestly better.

The advantage of the Spark setup is, as you mention, better acceleration at higher speeds. The other big benefit is more efficiency at all speeds but especially at higher speeds. The final benefit is that the low reduction gear ratio will give you a nicer more pleasant ride.

Aside from the drive train, the Spark is an ICE vehicle with some batteries. Not necessarily the greatest approach for an EV. However, the technology is really great.

 

[Nubo]

2011 leaf compared to the 2014 spark ev is not even close in technology and quality.

Much too early to reach any conclusions on Spark EV quality.

 

[TonyWilliams]

The final benefit is that the low reduction gear ratio will give you a nicer more pleasant ride.

How exactly is the gearbox related to a "nicer more pleasant ride"?

By the way, the Tesla Model S and Rav4 EV manage to get by with almost 10:1 gear reduction ratio... Please tell me how bad the "ride" is in those two cars.

 

[TonyWilliams]

All are worthy of your consideration. LEAF has more room, Spark EV is quicker, 500e more style. LEAF lacks thermal management, 500e lacks QC, Spark EV has a slow on-board charger. RAV4EV beats all the above at higher cost. Availability, and your personal needs will determine which is a better buy.

Rav4 EV is $15,400 off sticker price, plus $2500 from California (or whatever your state offers), $3999 down, $299 per month lease (plus California monthly "use" sales tax for us, or whatever your state is).

If you throw another $1000 on the down payment, it's unlimited mileage.

This is a result of selling 44 last month, putting them behind the 80-ish needed to be sold every month to meet CARB-ZEV quotas.

Must be purchased in California and shipped to your out of state address to meet CARB-ZEV compliance.

 

[SanDust]

How exactly is the gearbox related to a "nicer more pleasant ride"?

By the way, the Tesla Model S and Rav4 EV manage to get by with almost 10:1 gear reduction ratio... Please tell me how bad the "ride" is in those two cars.

The lower the GRR the smoother and less jerky the ride. Tesla uses a big expensive motor and a lot of batteries to overcome an inefficient drive system. The brute force approach is one reason why the Spark EV costs $17K and the Tesla costs $71K. Adding so much cost is fine for a luxury niche vehicle but way too expensive an approach for a mass production vehicle.

The comparison to the Model S is interesting. The Spark has a 140 hp motor and a 21 kWh battery pack and gets to 60 MPH in 7.6 seconds. The Model S has a 302 hp motor and a 60 kWh battery pack and gets to 60 MPH is 5.9 seconds. Taking the comparison further, the Leaf, using a 107 hp motor and a 24 kWh battery pack, needs 10 seconds to get to 60 MPH. No matter which way you cut it, the Spark performance is impressive and definitely the most cost effective.

 

[TonyWilliams]

How exactly is the gearbox related to a "nicer more pleasant ride"?

By the way, the Tesla Model S and Rav4 EV manage to get by with almost 10:1 gear reduction ratio... Please tell me how bad the "ride" is in those two cars.

The lower the GRR the smoother and less jerky the ride.

Sorry, but this is pure conjecture.

 

[Deleted member 9549]

2011 leaf compared to the 2014 spark ev is not even close in technology and quality.

Much too early to reach any conclusions on Spark EV quality.

The Spark non-EV is available in all 50 states. I rented one for 2 weeks. It doesn't seem all that impressive quality wise.

 

[Deleted member 9549]

“The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two).”

Spark EV - 402FtLb torque thru 3.18:1 drive = 1,278FtLbs axle torque
Fit EV - 189FtLb torque thru 8.05:1 drive = 1521FtLbs axle torque
LEAF - 207FtLb torque thru 7.94:1 drive – 1,643FtLbs axle torque

Isn't it axle torque that anyone cares about? If I have a super torqy engine but have to start in 5th gear, its not going to be very impressive.

Based on those numbers, does that mean that the Leaf has the most axle torque from a start? The 2013 is limited in software from a stop, but if it wasn't, would it be faster than the Spark? Does the 2012 Leaf feel faster than the Spark?