[skullbearer]

Ok, this was earlier posted here.


The question is:

Is it worth it to series or parallel my scooter's drive system with an electric assist/drive using only capacitors to store energy during idle and use less power in acceleration?



Here's some basic specs about the scooter, thanks to http://www.bikez.com/motorcycles/hon...elite_1985.php

These are for an '85 but the '87 is the same other than it has no fuel filter (which I'm going to add) and it has an analog speedo, not digital.


Model: Honda CH 250 Spacy/Elite
Year: 1987
Category: Scooter

Engine and transmission

Displacement: 249.00 ccm (15.19 cubic inches)
Engine type: Single cylinder
Stroke: 2
Compression: 9.8:1
Bore x stroke: 72.0 x 60.0 mm (2.8 x 2.4 inches)
Fuel system: Carburettor. Keihin
Cooling system: Liquid
Transmission type: Centrifugal CVT
Final drive: Belt


15hp @ around 5-6k rpm, though I cannot find the source I had linked once. Google hits the little '15hp' blerbs, but no rpm, and on all the pages it links I don't find the reference. Anyway, I think its about right though the motor is EXTREMELY torquey for a 250cc from about 2500-6000rpm, giving it a very strong and smooth takeoff up to about 55mph. It idles at about 1200-1500rpm.


It cruises at 55-60mph excellently with about 1/3 throttle, right at about 4500-5500rpm (it develops a very mild rpm whine that barely increases up to 70mph, which leads me to believe that it is hitting near max rpm and nearly max gearing on the cvt at that speed)

So I'm guessing its making about 5-8hp to do 55mph. With a fairly efficient cvt transfer I'm guessing 4-7hp is actually hitting the road (rough estimates for number generation here).

4-7hp = 2.98-5.22kW so I'm looking at a 5-8kW motor to be on the safe end. I would like to be able to keep my 65mph cruisability though in case I need to go on the freeway and be able to maneuver for safety reasons, and that requires a solid 1/2 throttle to maintain, so about 8-10hp

8-10hp = 6.08-7.46kW (you can see I'm using a 0.746kW/1hp conversion)

This means I'm leaning towards a 7.5-8kW motor here.


So I need a motor in 7.5-8kW that's either a wheel motor for a 10" rim (or one built into a 10" rim). The wheel if not the original stock must fit
[ 4.00x10 ] _ [ 110/90x10 ] tires. (that's U.S. and metric sizing of the same tire)


I cannot afford batteries or very very little of them, so I'm just asking the question in terms of capacitors only. I need enough capacitors to produce at least 10hp for about 4 seconds, preferably more power for the same time or the same power for more time. At that point I'm going about 45mph or a little more so I'm covered for my town start/stop routine.


This is for a 70mile round trip commute which is about 50% of the distance (or 3/4 of the time) start/stop situations with at most about 2 minutes of cruising at 40-50mph, and the other 50% of the time back road non-stop cruising of 50-65mph. (I'm currently doing 55mph which is general car traffic speeds because the lanes barely fit all the Hummers and large F-U Vehicles people drive around, and they freak out every time they pass each other).



So... what controller, motor, and capacitor setup do you guys recommend? No regen braking, no battery system, I've got a fair amount of space on the sides of the scooter (no saddle bags, and I'd just sling them over the caps anyway) for small or medium sized caps (preferably flat ones like lighter fluid cans).

[zig06]

I personally would not bother. Your scooter is already in the high 60mpg range, and the distance that it can go far exceeds what most EV's can do in a day (or at one time).

Consider rebuilding it and maybe even modifying the engine. There's lot's of new tech that has come along since your scooter was built, and if you took advantage of it, you might be able to get into the 90 mpg range. And that's not bad.

If you really wanted a EV-Hybrid, then in my opinion your going to need a bigger scooter. Because the weight of the battery, motor and controller will exceed it's limits.

[skullbearer]

I would be excluding batteries altogether in my ideal basic conversion on this. I just want to optimize the fuel economy, not make it into an EV. It wouldn't make the range or pay for itself before I'd be married, moved out, and sharing a car with my wife for a much shorter commute.


Now, you suggest I could update the tech to get 90mpg, and I would like to put a PFI (Port Fuel Injected) 250cc motor into it to get better power, response, AND economy, only I can't find any such singles that will fit in the space. Twins of all types are too large in the 250cc size, and truthfully I'm not going to put anything but a plug and play in for an increase of only 15mpg from what I'm already getting at economic speeds.

15mpg is a tiny increase from 74, and would only save me about $0.50 a day.

[zig06]

Ok, I never suggested that you install fuel injection of any kind. "Newer Tech" could be as simple as installing tires that have a higher PSI rating, which reduces Rolling Resistance and increase your MPG. Also, muffler designs have changed, and one that's just as quiet but flows better will get better MPG. A smaller flywheel takes less energy to spin, and that will give you better MPG. But you do need one so be careful in your choice.

Even a different carb and cylinder will have power and MPG increases if you really take the time to learn about the differences between your moped and a brand new one.

Now, your idea of using a "total loss" system of just producing electricity and using it as you do it, it's new. And I doubt that using capacitors will gain you anything as they do not really carry that much amperage (someone else needs to chime in on that).

Which leaves your idea down to just an engine powering a generator, which then in turns runs a hub motor. This is similiar to how a Diesel Locomotive works, only they have batteries, huge motors, huge batteries, and the "excess energy" goes to recharging the batteries.

In the end I believe that this is just not worth atempting in the time frame that you have stated. That system will require trial and error, and money to invest in new ideas. So in my opinion I recommend that you look into making your current ride better, and work on the hybrid when you have time and cubic dollars to spend.

So, either buy something better, or wait until you can apply yourself with a high level of time and money, into really doing this project right. This is because there is no quick, easy and inexpensive solutuion to what you are wanting to do.

Anybody else have 2 cents that they would like to share?

[skullbearer]

Sounds like pretty good suggestions, just that there are no off the shelf options for those sorts of things unless I want to order some custom pieces from Europe (thank you scooter gangs)


Definition of a moped is a motored and pedaled vehicle, and my 70mph scooter certainly don't have pedals, but its close enough.



Technically there are two classes of scooter (at least in the U.S.)

Scooter: Non-pedaled motor bike that does not exceed 35mph

Maxi-scooter: Non-pedaled motor bike that can exceed 35mph (and often reach freeway speeds)


Mine is technically a maxi-scooter and my registration card agrees with me.



As for engine and flywheel modifications, I know there is at least one bolt-on flywheel improvement, but I don't know about the pistons. There are also centrifugal weight adjustments available that will give me better low speed power or better top speed (just adjusts how quickly the cvt changes ratio).

I assume scooter mufflers will bolt on? I can't find many that match the pipe diameter though, most of those mufflers are for 125cc and smaller.

[zig06]

Well, this is a "electric bike" forum, not a "how to improve your ICE" forum. So even though the certification on the wall says that I'm a Master Motorcycle Mechanic, I'm just not interested in helping to improve the mileage of a 20 year scooter (mini or maxi).

Maybe consider spending some time finding a web site for CH-250's, and then ask them what can be done.

As for "off the shelve options", you need to be innovative. Just like many of the things that other EV users are doing here, having an idea is only a small part of it. Being able to design, debug and then perfect is a requirement, when you modify anything.

[skullbearer]

Originally Posted by zig06

Well, this is a "electric bike" forum, not a "how to improve your ICE" forum. So even though the certification on the wall says that I'm a Master Motorcycle Mechanic, I'm just not interested in helping to improve the mileage of a 20 year scooter (mini or maxi).

Maybe consider spending some time finding a web site for CH-250's, and then ask them what can be done.

As for "off the shelve options", you need to be innovative. Just like many of the things that other EV users are doing here, having an idea is only a small part of it. Being able to design, debug and then perfect is a requirement, when you modify anything.

I'm still not giving up on my capacitance idea, if only to screw around. I've found that I can actual get almost 1 minute of driving at 60mph for about $500 worth of large caps, which I can certainly fit. Now, I don't need but $100 of smaller caps to do my target 5 seconds (actually beat it) if specs aren't lying to me, and I can also screw around building a small 50amp controller at the same time.

Question is, can I find a generator that is small, cheap, and does 120VDC+?


:EDIT:

I've 'found' according to using the math and Farad ratings, not actually doing it.