Author Topic: Torque Curve  (Read 2286 times)

Squid

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Torque Curve
« on: August 23, 2010, 04:40:01 PM »
Now that the specifications are outlined on the Brammo site, I'm wondering when an Empulse rider could expect to see that 59 lb.-ft. of torque?  With an ICE optimum power is delivered at certain rev ranges, but I have no real idea about how a single speed electric motor behaves.  Is all that torque available all the time or, as one would expect, does it fall away as engine speed increases? 

I've read some interesting things about the Enertia's performance and how it feels gruntier than one might expect because significant torque is almost always on tap.  I'd love to hear from an Enertia rider about his/her experience.

Shane

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Re: Torque Curve
« Reply #1 on: August 23, 2010, 10:24:45 PM »
Two quotes below, from a motorcyclistonline.com article on the Enertia TTR, which seems to be the precursor/ prototype Empulse:

"There is no clutch or transmission; the direct-drive TTR is twist-and-go, like a scooter. Turn the throttle and the bike spirits away like a magic carpet. There is no vibration or driveline lash; a soft hum (like a ceiling fan turning on) and a bit of chain noise is the only indication that you are straddling a machine. Acceleration is brisk but hardly fierce. Theoretically, all 53 lb.-ft. of torque could be available from zero rpm, but the digital controller is programmed to deliver much less, both to save energy and to make the clutchless bike easier to launch."

So it's likely the Empulse will have a digital controller running the power delivery.  Customizable?!?

"An electric motor's power curve is the opposite of most internal-combustion engines. Max torque is available from zero rpm, and declines (eventually rapidly) as you approach the rev limit. The TTR, for example, loses almost 30 percent of its peak power by the 6000-rpm redline. As a result, the bike feels significantly more powerful from a standing start than during roll-ons. Wismann says this is a programmable variable as well. Increasing the voltage draw at the point where output begins to drop would mask the power fall-off, but would also cause a corresponding reduction in battery life. Adding a multi-speed transmission also would improve this situation, letting the rider upshift to reduce rpm-though that would be a costly and time-consuming solution."

Make of it what you will.  Read the whole article HERE.

lienly

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Re: Torque Curve
« Reply #2 on: September 12, 2010, 04:47:19 AM »
for such powerful torque at ZERO rpm, then can I wheely? :o

Two quotes below, from a motorcyclistonline.com article on the Enertia TTR, which seems to be the precursor/ prototype Empulse:

"There is no clutch or transmission; the direct-drive TTR is twist-and-go, like a scooter. Turn the throttle and the bike spirits away like a magic carpet. There is no vibration or driveline lash; a soft hum (like a ceiling fan turning on) and a bit of chain noise is the only indication that you are straddling a machine. Acceleration is brisk but hardly fierce. Theoretically, all 53 lb.-ft. of torque could be available from zero rpm, but the digital controller is programmed to deliver much less, both to save energy and to make the clutchless bike easier to launch."

So it's likely the Empulse will have a digital controller running the power delivery.  Customizable?!?

"An electric motor's power curve is the opposite of most internal-combustion engines. Max torque is available from zero rpm, and declines (eventually rapidly) as you approach the rev limit. The TTR, for example, loses almost 30 percent of its peak power by the 6000-rpm redline. As a result, the bike feels significantly more powerful from a standing start than during roll-ons. Wismann says this is a programmable variable as well. Increasing the voltage draw at the point where output begins to drop would mask the power fall-off, but would also cause a corresponding reduction in battery life. Adding a multi-speed transmission also would improve this situation, letting the rider upshift to reduce rpm-though that would be a costly and time-consuming solution."

Make of it what you will.  Read the whole article HERE.
hope can be Brammo Taiwan exclusive agent!