Idea for making a street legal go kart or dune buggy

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Elwyn
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Idea for making a street legal go kart or dune buggy

I saw that there is a go kart forum, but from what I saw, none of them were street legal, so I think this is a more appropriate place for this thread. I live in Fort Worth, TX about 5 miles each way from where I work. The fastest speed limit on the roads I take is 40 mph. I would love to buy or make an electric vehicle for my commute. The new electric scooters/motorcycles looked pretty good, but I saw a post saying it overheated when it was under 80 deg F outside. (What would it do when it is over 100 deg F here?) Also, I'm not too fond of the idea of spending that kind of money on something I haven't seen or test driven from a company I know very little about. I'm not currently a motorcycle rider, so I'm not sure about safety. I would get an electric bicycle, but there are no bike lanes and lots of traffic. Hmm, maybe that's why we frequently have air pollution watches here (some people need to wake up). All the electric vehicles I have seen for sale are really overkill for my commute and thus more money than I want to spend.

So, I started thinking about making my own go kart or dune buggy electric vehicle. Does anyone have any idea what would be required to get it street legal in Texas?

I started pricing out things I think I would need (suggestions are welcome here):

go kart kit $600 with shipping; http://www.northerntool.com/shop/tools/product_200356855_200356855

Motor—8 hp cont, 15 peak, $434 + ? shipping; http://www.cloudelectric.com/product_p/mo-me-0708.htm

200 amp controller with reverse and regen (80 amp cont.); $295 + ? shipping; http://www.cloudelectric.com/product_p/co-pm48201.htm

pedal throttle; $109.95 + ? shipping; http://www.cloudelectric.com/product_p/th-kp-0-5k.htm

4x 85 AH Trojan batteries 24TMX-12V; $488 + ? shipping; http://stores.energywisesolutions.net/-strse-1341/24TMX-12V-Deep-Cycle/Detail.bok

Throwing in about $150 for wiring, lights etc, gives me a total cost of about $2,100, maybe $2,500 with the shipping and tax.

Total weight should be about 670 lbs including me. (I'm only about 170 lbs of it.)

As you can see, I found a lot of things at cloudelectric. Are they a good company?

Any advice on the whole thing would be greatly appreciated. I'm an engineer, so amps, volts, rpm, etc. are easy for me to understand (at least in theory--no practice with EV's yet). My Dad will help on the construction. He has a shop with a welder and other equipment. I think we would make a good team on this project, and going 40-45 mph max for 10 miles round trip doesn't seem like a tall order. I eagerly await your comments, good and bad.

reikiman
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Re: Idea for making a street legal go kart or dune buggy

I don't know the laws in Texas - but I am doubting a "go-kart" can be made street legal. If you're feeling serious enough maybe you can prove me wrong. What I'd suggest is go to your DMV website and look into the requirements for registering custom built cars.

It sounds like you're more interested in Transportation than specifically making a street legal go-kart?

The BugE is pretty close to what you're talking about - a bit higher priced but not too high - it's a three wheeler hence registers as a motorcycle. It comes as a kit and you assemble pieces and parts of the sort you found.

- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
- Electrified Electra To

Elwyn
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Re: Idea for making a street legal go kart or dune buggy

Maybe calling it a sand rail would be more appropriate. At least to me it looks similar to pictures of sand rails that I have seen advertised as street legal. Trying to find anything on the web on Texas law for vehicle registration is very frustrating. I just called someone at an inspection station, and he said he thought it would fail the emissions test since they can't hook their computer up to a spark plug wire and I live in a county where emissions tests are required. (The laws haven't kept up with EV's, or he just doesn't know about an exemption if there is one.) He also said if it was over 25 years old a lot of the safety tests were easier to pass or non-existent.

Yes, I am primarily looking at this for transportation. The sand rail frame just seemed to be a cheap and light weight way to get started with an electric vehicle.

I had looked at the BugE before and it does look good, but almost $4k for the body and wheels with no batteries, motor, or controller seems expensive. Do you know what wattage or horsepower motor they put in their power kit? Also, it doesn't seem any safer than what I was looking at. I guess the only way it is street legal is that it is 3 wheels and registered as a motorcycle. I was considering asking my Dad how much work he thinks it would be to convert the frame I mentioned above to just one wheel in the back like the BugE. I guess that would make it easier and cheaper to register it, but I would have to find out if I would need a motorcycle endorsement on my license to operate it then.

marylandbob
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Re: Idea for making a street legal go kart or dune buggy

The batteries mentioned are too small/low powered for your 8 to 15 horsepower motor, as they are rated at only 36 minutes service with a load of 75 amperes, or less than 5 horsepower for 36 minutes, when new. You would very likely deplete them in about 5 minutes or less, if you attempted to generate 15 horsepower! Your controller should also be bigger,as the motor can demand up to 400 amperes, and this may cause blowout of the 200 amp unit. Registration requirements are much more involved for a vehicle withover 3 wheels, and your proposed chassis has wheels thatare too small for highway use, no highway capable brakes, no suspension(springs/shock absorbers), no lighting system/turn signals/horn/odometer/speedometer, windshield, brakelights, etc. Tires mounted on rims of at least EIGHT inch diameter are required in most states for highway use. Front and rear brakes are also normally required. I think, when you realize what is required to be SAFE and LEGAL, you will see that the prices being demanded by the commercial concerns do have some justification! (You must ALSO consider that getting INSURANCE for a homemade vehicle may be very difficult or impossible!)---Sorry, but I would not advise you to proceed.--Bob Curry

Robert M. Curry

Elwyn
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Re: Idea for making a street legal go kart or dune buggy

How much horsepower do you think it would take to keep this type of vehicle at 40-45 mph? The 75 amps from the battery for 36 minutes would give me 4.8 hp or about 40 pounds of push at 45 mph. I don't really know how much it would need though. Currently, I make the drive in about 15 minutes each way (5 miles). The 200 amp controller (at 48 V) should give me almost 13 hp for one minute. I was assuming that would be for accelerating and going uphill which would be of short duration. I don't understand where you get that the motor could demand up to 400 amps. The highest current the spec charts for the motor show is about 190 amps. If I take 15 hp and convert it to watts, I get 11,190 watts. At 48 V, 11,190 watts should only be 233 amps. Is 400 amps a start-up current? Where do you find that or how do you figure it? Do these controllers not limit themselves to keep from overheating or passing too much current? Does the motor/controller combo need to be sized the other way around? In other words is it possible for too big a motor to hurt a controller but not possible for too big a controller to hurt a motor?

I have no intention of taking this thing on the highway. It will only see a 40 mph speed limit at most (45 mph would be my target max speed). The tires are 16 inch diameter (16 x 6-6). I have seen several electric scooters for highway use that have 14 to 16 inch wheels, so I don't know why you say they are too small for highway use. Anyone know how big the rims would be on a 16 x 6-6 tire? (I'm pretty sure those numbers tell you how big the rims are, but I don't know how to figure it.) I was/am worried a bit about the brakes myself which is one reason I chose the controller with regen. Even with that, new/additional braking may be required. I think the tires are intended to be the springs and shock absorbers, but maybe that won't be enough. I was planning to add the lighting system/turn signals/horn/odometer/speedometer/brakelights. It may cost way more than I allowed, but I did mention $150 for wiring, lights etc.

Would it really require a windshield? If so, maybe this is another way motorcycles have lower or non-existent requirements. That would be another reason to rework the rear end and make it just one wheel in the back.

The stability of 3 or 4 wheels and the roll cage seem much safer than a motorcycle at least to this non-motorcycle rider.

I have not purchased any of these items yet. I do still need to do some checking on actual requirements from DPS or DMV then find out about insurance.

marylandbob
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Re: Idea for making a street legal go kart or dune buggy

The amperage at PEAK power will be much higher than the chart shows! The chart shows current for CONTINUOUS power. Some controllers do have an adjustable current limit, but others will fail if too much is demanded. The WHEELS are specified as beind 6 inch diameter, some states do not allow such small wheels on road/street/highway vehicles, regardless of TIRE diameter.There is also no differential, which means that you are likely to drive only ONE wheel, making for poor handeling, especially under regenerative braking, which, in any case, isnot suitable as the only braking in traffic. As forthe "Roll Cage", it may offer protection ina single vehicle incident, but it is not ofthe construction needed to protect in cases of collision with a car or truck. (A heavier frame,and 4130 chrome-moly steel, costing and weighing much more, would be required) Keep in mind that neither batteries,motors, wiring,or controllers are 100% efficient, so you are likely to need around 15 kilowatts of battery power to produce 15 horsepower of motor output,and your small battery will decrease its voltage under heavy load, possibly as low as 40-42 volts at 300 to 400 amperes, and 400 times 40 is 16 kilowatts,(OK) or 300 times 42 is only 12.6 kilowatts, not quite enough! A battery with higher capacity will have lower internal resistance, and be able to provide higher loaded voltage and motor power.(There is also voltage loss in the wiring and controller, smaller controllers generally having more loss at any given amperage)--I would advise using 16 cells of lithium-Iron phosphate, rated for 100 ampere-hours or better,as a suitable battery for your specified motor.--You willalso require a D.C. to D.C. converter, to reduce the battery voltage of 40 to 60 volts down to 13.8 volts topower your lights and accessories. (So called "12 volt" automotive devices perform best around 13.8 volts, as found in a car, with the engine running and alternator charging the battery.)--Bob

Robert M. Curry

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Re: Idea for making a street legal go kart or dune buggy

If you're afraid of 2 wheels, how about 3? Some of these manufacturers make the same scooter that way, NOT a mobility scooter.

I just don't think anything in the opening statements supports the notion of converting anything from the wide range of "GoKart" to driving on the street. If you think the scooter would be dangerous. . . .

If you're so ready to build, you can pick up a more or less proven concept kit, at least ahead your experiment on the curve, for $5k. This one is also available assembled for a bit more.

That's only the beginning. There's such things out there that already work. I just think if you built that kart, you'd be learing why more people weren't doing it.

WHo dares, WINS!!!!

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