ElectricMotorcycleForum.com

  • January 19, 2018, 07:37:33 AM
  • Welcome, Guest
Please login or register.

Login with username, password and session length
Advanced search  

News:

Electric Motorcycle Forum is live!

Pages: [1] 2

Author Topic: LS-218 vs H2  (Read 464 times)

ultrarnr

  • Sr. Member
  • ****
  • Posts: 387
    • View Profile
LS-218 vs H2
« on: October 29, 2017, 02:55:35 PM »

In the December issue of Motorcyclist magazine there is an article about the Lightening LS-218 taking on the Kawasaki H2 in the quarter mile. It is not full of technical details and is more of a gasoline vs electricity type of article. In the end the H2 completed the quarter mile at 148 MPH and 9.94 seconds with the LS-218 less than a hundredth of a second and 4 MPH behind.
Logged

Frank

  • Jr. Member
  • **
  • Posts: 58
    • View Profile
Re: LS-218 vs H2
« Reply #1 on: October 31, 2017, 08:42:24 AM »

I saw this article too.  Two of the fastest stock motorcycles on the planet right there.
Logged

MrDude_1

  • Hero Member
  • *****
  • Posts: 959
    • View Profile
Re: LS-218 vs H2
« Reply #2 on: October 31, 2017, 07:16:58 PM »



The zero is on here... maybe the Lightening should be too?

https://en.wikipedia.org/wiki/List_of_fastest_production_motorcycles_by_acceleration
Logged

Doug S

  • Hero Member
  • *****
  • Posts: 1126
    • View Profile
Re: LS-218 vs H2
« Reply #3 on: October 31, 2017, 08:17:19 PM »

I doubt Lightning (btw there's no "e" in "Lightning") is considered a production vehicle. Don't know what the standard is for the list, but no way Lightning meets any reasonable criteria for homologation.

When I found the Zero SR on the list, I thought "they need to update that, the newer one is faster". But then I realized most of the bikes are old! Someone really needs to spend some time updating that list.
Logged
There's no better alarm clock than sunlight on asphalt.

MrDude_1

  • Hero Member
  • *****
  • Posts: 959
    • View Profile
Re: LS-218 vs H2
« Reply #4 on: October 31, 2017, 08:53:20 PM »

(btw there's no "e" in "Lightning")

lol, that's what I get for copying the initial post.

When I found the Zero SR on the list, I thought "they need to update that, the newer one is faster". But then I realized most of the bikes are old! Someone really needs to spend some time updating that list.
often bikes stay the same with respect to performance and mechanical for about 5-8 years. Or the new one is slower because its heavier or geared differently. You cant always go off of age as a factor.
Logged

Doug S

  • Hero Member
  • *****
  • Posts: 1126
    • View Profile
Re: LS-218 vs H2
« Reply #5 on: October 31, 2017, 10:16:51 PM »

You cant always go off of age as a factor.

I can with the Zero. I know for certain that the 2014 isn't as quick as the later models. I have to figure at least some of the others are out-of-date too.
Logged
There's no better alarm clock than sunlight on asphalt.

Frank

  • Jr. Member
  • **
  • Posts: 58
    • View Profile
Re: LS-218 vs H2
« Reply #6 on: November 01, 2017, 05:33:29 AM »

A 12 second time for the 1/4 mile is ridiculous!  That is considered slow these days.
Logged

Doug S

  • Hero Member
  • *****
  • Posts: 1126
    • View Profile
Re: LS-218 vs H2
« Reply #7 on: November 01, 2017, 06:22:24 AM »

A 12 second time for the 1/4 mile is ridiculous!  That is considered slow these days.

It is. The Zero's forte has never been top speed. High speed requires high horsepower, and the current SR only puts out 67 hp. My bike (a 2014) doesn't even put out that much (The actual number escapes me just now). But electric motors are all about the torque, and torque is what determines 0-60 time. Torque is also far more useful and satisfying in the real world. Outside of a race track, you can't use a 150 mph top speed anywhere (legally), but you can use all the torque you've got at every stoplight and stop sign.
Logged
There's no better alarm clock than sunlight on asphalt.

JaimeC

  • Hero Member
  • *****
  • Posts: 505
    • View Profile
    • Facebook page
Re: LS-218 vs H2
« Reply #8 on: November 01, 2017, 10:05:59 PM »

As someone once posted:  "Horsepower is how fast you hit the bridge abutment. Torque is how far you knock it out of position."
Logged
2016 Zero S: Short trips in traffic
2013 BMW C650GT: Long trips in traffic
1999 BMW K1200LT: For everything else

MrDude_1

  • Hero Member
  • *****
  • Posts: 959
    • View Profile
Re: LS-218 vs H2
« Reply #9 on: November 01, 2017, 11:23:44 PM »

As someone once posted:  "Horsepower is how fast you hit the bridge abutment. Torque is how far you knock it out of position."

•Horsepower is how fast you hit the wall.
•Torque is how far you take the wall with you.
•Understeer is when you hit the wall with the front of the car.
•Oversteer is when you hit the wall with the rear of the car.
•Low side is when the bike slides into the wall.
•High side is when you're thrown over the wall.
Logged

Alan Stewart

  • Full Member
  • ***
  • Posts: 178
  • Electric Transportation Enthusiast
    • View Profile
Re: LS-218 vs H2
« Reply #10 on: November 02, 2017, 06:31:50 AM »

They’re directly related to each other, not disparate properties.

Torque times engine/motor speed times some conversion factor = horsepower

If you have zero torque at any engine/motor speed you will also have zero horsepower at that speed.

If you have x torque and y horsepower at some engine/motor speed and x torque at twice that speed there will be 2y horsepower at the higher speed. If torque is double at the higher speed there will be four times the horsepower at the higher speed.

Electric motors have more torque at lower speeds thus have more horsepower at those speeds.
Logged
Alan
2014 Nissan Leaf, Tesla Model 3 reservation

Doug S

  • Hero Member
  • *****
  • Posts: 1126
    • View Profile
Re: LS-218 vs H2
« Reply #11 on: November 02, 2017, 08:08:03 AM »

They’re directly related to each other, not disparate properties.

Yes, they're related. They're not the same thing.

Quote
Torque times engine/motor speed times some conversion factor = horsepower

Numerically, horsepower = torque (in ft-lbs) * rpm / 5250.

Quote
If you have zero torque at any engine/motor speed you will also have zero horsepower at that speed.

Sure, what's your point?

Quote
If you have x torque and y horsepower at some engine/motor speed and x torque at twice that speed there will be 2y horsepower at the higher speed. If torque is double at the higher speed there will be four times the horsepower at the higher speed.

Your math skills are good.

Quote
Electric motors have more torque at lower speeds thus have more horsepower at those speeds.

That's true, but fairly irrelevant. Think about riding a bicycle. Accelerating away from a dead stop, the limiting factor is how hard you can push on the pedals. You're up against your torque limit. Low gears help by multiplying the torque at the rear wheel, by increasing the mechanical advantage...but, of course, limit your top speed by the same factor.

But when you're hammering at top speed on the flat, your limit isn't how hard you can push on the pedals. You can push even a fairly tall gear easily in terms of leg strength. Your heart and lungs (your aerobic capacity) are the bottleneck, not your leg muscles. You're no longer torque limited, now you're power limited.

Any vehicle has to face the same TWO limits -- a torque limit and a horsepower limit. At any given time, one is usually irrelevant because the other dominates. In general, at low speeds, you're torque limited, at high speeds, you're power limited.

One final consideration is that ICEs, by their very nature, take in and combust more fuel/air mixture as rpm increases. A four-cylinder engine idling at 600 rpm has 20 power strokes per second. At 6000 rpm, it has 200 power strokes per second. All other things being equal, that will result in 10 times the power output, and (at the motor output) 10 times the torque. And indeed, our experience tells us that ICEs really come alive as rpm increases. So at low rpm, where road speed is low and you need lots of torque, the ICE just doesn't have any. You need lots of gearing advantage to get out of the hole. But as speed (and rpm) increases, available torque and power skyrocket. That's just the nature of an engine whose power is produced in pulses which occur in proportion to rpm.

By comparison, an electric motor has full torque literally down to 0 rpm. That's still 0 power at 0 rpm, but you don't need horsepower down there. You need torque, which an electric motor provides in spades. But at high rpm, since the electric motor's available torque doesn't rise like the ICE's does, the horsepower curve flattens and turns downward while the ICE's is just coming into its band.

Bottom line, ICEs rule in top speed, EVs rule in low-speed acceleration. Obviously the transition speed varies based on a lot of variables, but my SR feels like it far outperforms my old ZX-11 in freeway roll-ons. The transition speed must be pretty high.

Long story short: Torque is good, torque is what accelerates you. Power just pushes air out of the way at high speed.
Logged
There's no better alarm clock than sunlight on asphalt.

speedkills

  • Newbie
  • *
  • Posts: 14
    • View Profile
Re: LS-218 vs H2
« Reply #12 on: November 02, 2017, 09:21:41 AM »

Long story shorter.  Doug makes an incorrect statement about torque vs hp. Alan corrects the statement.  Doug Trumps Alans statement by saying so many irrelevant things you will get bored before you finish reading them and now feels he has proven he was right the whole time.
Logged

MrDude_1

  • Hero Member
  • *****
  • Posts: 959
    • View Profile
Re: LS-218 vs H2
« Reply #13 on: November 02, 2017, 08:04:12 PM »

He also made the incorrect association that a ICE vehicles motor RPM is directly correlated to vehicle speed.
It happens often, especially in EV forums.
Logged

Alan Stewart

  • Full Member
  • ***
  • Posts: 178
  • Electric Transportation Enthusiast
    • View Profile
Re: LS-218 vs H2
« Reply #14 on: November 04, 2017, 08:08:45 AM »

I made no such assumption, I simply didn’t address it as it is irrelevant to understanding the difference between torque and power. I have 45 years of experience with manual transmissions in range of vehicles from motorcycles to dump trucks.

What prompted my posting was the silly idea that how far a bridge abutment is moved as a result of running into it is a example of torque. It is not. That is an example of kinetic energy, speed times mass. Torque is the force it would take to stall the motor. Power is the result of motor’s torque over so many revolutions of the motor. Acceleration and speed are the result of power over time.

There’s no fundamental difference between electric motors and internal combustion engines which results in the first being better at torque and the latter at horsepower. But there is a fundamental difference between a single speed and a multi speed transmission. A multi speed transmission is better a delivering maximum torque, and thus maximum power, across a wider speed range.  While ICE generally requires a multi speed transmission to make a practical vehicles, that is not the case for electric motors. If someone really wanted both at the same time in an electric vehicle they’d put a multi speed transmission in it.
Logged
Alan
2014 Nissan Leaf, Tesla Model 3 reservation
Pages: [1] 2