Brammo Owners Forum
Brammo Empulse Discussion => Brammo Empulse => Topic started by: protomech on February 13, 2013, 01:34:58 PM
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Would like to get some feedback from owners.
Does the owner's manual list the gearing ratios for the Empulse transmission? If not, could one of our owners report back mph:rpm ratios for each speed? You may find it easiest to hold a particular RPM and then estimate speed, or hold a particular speed and then estimate RPM. Either format would be fine.
1st gear: 5000 RPM @ 38 mph
or
1st gear: 5800 RPM @ 45 mph
Doesn't have to be exact. Just trying to get a feel for the bike.
Also, can anyone get an approximate full power 0-60 mph time for the bike? Both in Normal mode and Sport mode? (Feel free to repeat this test as often as needed :D)
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From memory, here are a few gears:
2nd: 5000 RPM @ 45 mph
3rd: 5000 RPM @ 50 mph
6th: 3500 RPM @ 60 mph (i.e. you can hit the highway during the break in period!)
I'll see about getting better data tonight.
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Here is what I have:
1: 38 mph @ 5000
2: 47 mph @ 5000
3: 57 mph @ 5000
4: 66 mph @ 5000
5: 63 mph @ 4000
6: 61 mph @ 3500
I hope that's all you need. The speed limit is 50 where I was testing so I wasn't going to try for 5000 rpm at 6th gear!
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I was wondering what is the best "gear" and speed to get optimum range?
When I am just cruising at 55 mph at 4000 RPM, I think in 4th...I would think the range indicator would go up, but it doesn't seem to have as high of an estimated range vs lugging it in 6th at a lower RPM (non-optimum RPM).
Where are you guys at speed and RPM wise to get maximum range?
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I'm still experimenting with what gives max range, but for now I'm following the words of Adam Lukovic that somewhere around 7000 rpm in Normal mode and 6000 rpm in Sport mode have the motor working in the most efficient band.
What gear that is depends on how fast you want to go. Today I was shooting for some good range to get to where I wanted to ride and had to take the freeway for most of the route. I don't feel safe, even in the slow lane, at under 50 mph and prefer 55 to 60. This called for second gear to hold the revs up in that optimum band. I mostly rode with 1 or 2 green lights on which, in 2nd, is around 63 mph. 1st gear hits the optimum band around 50 mph.
Air temp was 49F and I did 56 miles and returned home with 18% charge remaining. I didnt' "hypermile" it, but I didn't juice it hard off the stops either.
After 1500 miles, I've grown to love the sound of the motor whirring along at steady high rpm's.
Can't wait to see what warmer air temps do to the range. Or graphene capacitors. 8)
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There's a forum wiki page with the answer to that question.
http://www.brammoforum.com/wiki/index.php?title=Empulse_Motor_Efficiency (http://www.brammoforum.com/wiki/index.php?title=Empulse_Motor_Efficiency)
Check out the rest of wiki for other interesting info.
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I'm still experimenting with what gives max range, but for now I'm following the words of Adam Lukovic that somewhere around 7000 rpm in Normal mode and 6000 rpm in Sport mode have the motor working in the most efficient band.
You are quoting the RPM targets for best power/acceleration. In a later note (link (http://brammoforum.com/index.php?topic=1757.msg13912#msg13912)), after he conferred with the powertrain design engineer, he clarified that in both Sport and Normal the most efficient RPM range was right around 5000 RPM. Also, the power target was 5K for sport, not 6K. It will be interesting to see if you get any better range aiming for 5K if you've got any objective benchmarks to compare against your current strategy.
So, the recommendations on the table are:
Sport - 5K best power, 5K best range
Normal - 7K best power, 5K best range
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Thanks for the correction... will give it a try.
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5000 it is! thanks for the info
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Well I seem to be getting more range at 5000 RPM, though I also have been fiddling with lower tire pressures, so can't really offer any data with any precision right now.
I have a question about the Range Indicator: How do I use it? It makes no sense to me!
When I turn on the bike each morning, it says I have 120 miles. Then, as I drive, it changes, but the changes happen very often and the swings between numbers are quite large. I'm assuming the computer is running some sort of moving average, but the data set analyzed doesn't seem large enough to garner any stability by meaningful curve smoothing, rendering what could be a very useful tool, not so much.
Or am I just failing to understand how to use this tool? (Often wrong; never in doubt!)
Thanks,
Bill
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Shinyside,
I think it is more of an instantaneous range projection. I too find it changes too much to be super useful. But wanted to give it more miles for me to get use to it.
Does the enertia do this also?
Tesla has a ideal range and an estimated range that is pretty dead on.
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Does the enertia do this also?
Yes. I pay more attention to the state of charge and do most of my estimating based on that. Plus, my commute doesn't differ much from day to day, so I know what to expect and am never taken by surprise.
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My Vectrix also had such a random number generator. I now run custom firmware which displays pack voltage in the range field. Much more useful, especially with the NiMH batteries!
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Well, our battery indicator is a useful voltmeter and I can sort of estimate range from it, but it seems silly to have a Range readout that is so squirrelly.
I mean, we've got sensors. We've got computer chips. We've got the ability to do digital math and smooth a moving average, factoring in SOC, recent Amp-hour history, battery temperature, recent average speed, historical average speed since last full charge, etc..Don't we?
As it now stands, any lingering range anxiety that bubbles to the surface is exacerbated by a Range readout that flops from 63 to 28 miles. Makes me queasy!
If Tesla can do it, why can't Brammo?
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I agree that the range indicator isn't all that useful. I'm almost always running the battery to empty whenever I do my 77 mile commute, so range is a very important thing for me to be aware of. The SOC (battery level) indicator is the most important tool, and it's accurate in that when it gets to 0, you're done.
The way I use the dashboard is to reset the trip meter when I start (at 100%) and check my range every time I get to factor of 10% SOC. (90, 80, 70, etc.) Then I calculate my expected range based on the past range. E.g. Say that at 90% I've gone 10 miles. That means if I keep riding in the same way I can do 100 miles. Over time, that maximum range will change as I go faster or slower, but given that I have a specific range I'm trying to get to (77 miles), I can use that simple calculation to tell me if I can go faster (i.e. use more energy), or if I have to slow down.
The range indicator does settle down if you can hold a constant speed for some time, and that is the number you should use for your range estimate. Changing speed (accelerating or braking), changing elevation (going up or down a hill), and wind (head or tail wind, or drafting behind a bus) will significantly affect that number, so you have to decide if you are going to be in that state for a long time, or if you should ignore the indicated range for a while.
I like the way that my van estimates range. Basically, it uses fuel remaining with an average fuel consumption per mile. I'm not sure how long it keeps data to make the average, but it's fairly long, so if I've been driving conservatively for a few days and then I drive like a hooligan, the range estimate will be very wrong. I can manually reset the counter when I change my driving style to get a more current estimate.
Once nice thing about the fast changing range indicator is that you can immediately see how what you are doing will affect your range. E.g. See how the range is affected when you sit up vs. hunch down, or when you go faster vs. go slower.
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Other than playing with the display modes for the first week or so, I basically have not even touched the button to change modes to anything other than the kW consumption metric. (the +/- kW number) I don't find any of the other numbers useful for the vast majority of my riding. The temperature stats are good to have, but there's the giant bar that appears to tell me whenever the battery is too cold (and I presume when the battery is too hot, but thankfully I haven't run into that situation yet).
The kW usage figure can tell me at a glance whether or not my current riding pattern is sustainable over the period I want to be able to travel -- and I'd much rather see that actual figure displayed than an arbitrary number of miles calculated from that figure. Also it is ever-so-satisfying to see the regen putting some juice back in the batteries.
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The range indicator does settle down if you can hold a constant speed for some time, and that is the number you should use for your range estimate. Changing speed (accelerating or braking), changing elevation (going up or down a hill), and wind (head or tail wind, or drafting behind a bus) will significantly affect that number, so you have to decide if you are going to be in that state for a long time, or if you should ignore the indicated range for a while.
First of all - Thanks for the comments. We do know we need to spend more time on the range indicator - it's the only "predictive" function of the dash - i.e. all other displayed values are real-time statuses. The size of the battery pack and the range of usage (possible C-rate draw) on the pack makes this somewhat tricky to find the right duration to use to show an average. At the moment, it is really only useful for highway commuting - i.e. sustained speeds. It becomes much less useful once there's a change in power. I have never used the range estimate, but can appreciate some riders do like to use it. The test riders we have at Brammo seemed to be using it for estimating freeway miles at a constant speed, so this is how we set it up. We'll see what improvements can be made for future software updates.
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BMW has been using a range indicator on their motorcycles for the past few years - with mixed results. The early versions started counting down the miles left once you reached and estimated 50 miles of gas left in the tank. That worked fine for me, because I ride at a steady speed all the time, but not so much for may other people - including the motorcycle press, who had a tendency to run out of fuel with 10 or 15 miles left showing on the computer. Since then BMW seems to have dropped the countdown feature and just lets you know when you have reached your "reserve" fuel at an indicated 50 miles of range left, based upon your average mileage during your current ride. They then show the number of miles that you have ridden since hitting "reserve". I am not quite sure how the latest models handing the issue, but it can be a real head-scratcher for a designer, as you can never really predict what an owner is going to do with your bike in the field. All you really know is that if they run out of "gas" and have to start pushing, they are going to be really unhappy - not a good thing. So the conservative approach to estimating range usually wins out.
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Here is what I have:
1: 38 mph @ 5000
2: 47 mph @ 5000
3: 57 mph @ 5000
4: 66 mph @ 5000
5: 63 mph @ 4000
6: 61 mph @ 3500
I hope that's all you need. The speed limit is 50 where I was testing so I wasn't going to try for 5000 rpm at 6th gear!
Extended out for 5000 RPM:
1: 38 mph
2: 47 mph
3: 57 mph
4: 66 mph
5: 79 mph
6: 87 mph
So for best efficiency, you probably want to stay in the following gears:
1: < 42 mph
2: < 52 mph
3: < 62 mph
4: < 72 mph
5: < 83 mph
6: > 83 mph
Minor deviations probably have little effect on efficiency, for example staying in 3rd gear for 55 mph but cracking the throttle open for a 65 mph pass would be just fine.
Edit: put another way
1: 7.6 mph / 1000 RPM
2: 9.4 mph / 1000 RPM
3: 11.4 mph / 1000 RPM
4: 13.2 mph / 1000 RPM
5: 15.8 mph / 1000 RPM
6: 17.4 mph / 1000 RPM
Final drive is 14 front : 48 rear, or 3.43 gearing. (Edit: Empulse R is 14 front : 38 rear. The 48 rear sprocket is from the Empulse specs (http://www.brammo.com/empulse_specifications/) page, maybe it is for the E1 Empulse).