large road legal electric go kart build. need help!

I am embarking on my journey to build an electric daily driver go kart . I was considering an E grom for daily use but figured a go kart would be ALOT more fun. so here I am. My intent is to build a machine that can gladly run at 65 mph for many miles. to make it suitable for daily driving.
I am starting with hopefully a Roketa chassis platform, it should weigh about 600 pounds. it is a 250cc style buggy with full independant suspension and should have plenty of room for batteries.

My initial challenge is this.

one : selecting motor type

two : selecting motor power.

three: selecting controller

four: selecting amount of power to run it,

five: charging in an easy manner


i look for motors and most top out at 3500 RPM, which means to me i will need heavy gearing to get me going. unless i find a powerful high RPM motor. I cant seem to find one so i am looking for suggestions.

next, id prefer a brushless motor for efficiency. ill get alot more range and power from a brushless motor, but then i am looking at adding a reverse gear for... reverse.

then of course comes the topic of the controller. but first we need to pick a motor


for the battery im thinking of stealing battery off an old chevy volt. i found a few 48v 47ah packs for real cheap that would work well i think but i dont know how i would go about charging this . I would love your guy's ideas on this!


as a final touch i do want to run a 12v circuit for accessories and somehow charge the system , maybe a solar panel? seems simpler than running a mini alternator.

Hi,

Where are you located? This is important because your location makes a huge difference regarding the road legal rules.

I know here (QLD, Australia) making a "Gokart" road legal is absolutely impossible.

But you might like to see my build: https://endless-sphere.com/forums/viewtopic.php?f=34&t=76189
It's not road legal here but in another location the rules might be more relaxed.

i live in Arizona, which luckily as long a the kart meets a certain criteria. like height, proper lights, and horns , they are perfectly fine to be registered!

i love your build! what motor and controller combo did you use?

Half your luck. Maybe I should move there.

It's an advanced dc 9 inch fb1-4001. The controller is a zeva 1000amp unit.

I canibalised a cheap front wheel drive wreck and used all the running gear from it. The basic dimensions match the donor car so I could use the standard drive shafts etc.

where did you get that motor and speed controller combo? what kind of speed do you get from your kart? yes move here! we can be EV palls haha!

The motor was on ebay. I purchased the controller from the Zeva website. I haven't had a chance to test top speed with the new controller. But with the 5 speed gearbox I should be able to hit 160 kmph or about 130mph. But for me the acceleration is more important. In the events I run we realistically only get to a shade over 100kmph or 60mph before the next corner.

does a gear box work really well? does it have a hard time coping with the torque? ive been contemplating a gear box in my build because i do need this vehicle to do at least 60

here is the chassis i want to use for the build http://www.gokartsusa.com/productimages/GK-0602.JPG

I can't find your buggy at gokartsusa, you sure it's not discontinued? What you want is to be sure you're getting one with front and rear brakes, I don't think yours looks like it has fronts.

I crunch on this idea a lot, if I won the lottery I would need several, for different purposes. Street transportation benefits greatly from there being some bodywork. http://gokartsusa.com/BMS-Avenger-150-MAX-UTV-Side-by-Side-1.aspx This one is 528 pounds, I"m sure it would exceed that by the time you replace the the engine with some batteries. I'll bet the one you wanted was $4,500, this one is $2,238.

$160 more, also claiming front brakes, maybe you'll like the look better. http://gokartsusa.com/kinroadphoenix150buggy.aspx



What's high on my list should I suddenly be able to afford such an adventure would be a glass dash.

http://www.extremetech.com/extreme/131485-digital-dashboard-why-your-cars-next-instrument-panel-will-be-one-big-lcd

It has been long discontinued I believe it does have 4 wheel disc brakes luckily. My guess is this one weighs 800 ish but it could be lower since its all tube frame. I'm hoping the weight is low enough that a 5kw motor will be enough to get me to 60mph with gearing. Do you guys think I should do a 5kw brush less or a 10kw brush less? Also what should I do for a dashboard?

If you look at those links both have some modest flight decks. The glass deck I posted is $5k, don't know what your budget is.

One other consideration is that the wheels on these things are usually 8-10", I don't think you'll find DOT tires that size. There were some 14" wheels and tires that would push over $1,200 and you'd just have to replace the tires. There are adapters, but maybe there's other options for wheels. I have an old set of 4 bolt wheels from my old Fox body Mustang when I replaced them with some turbines I got cheap. Dang, wish I'd kept the turbines when I sold it, eh? Such a fun project, but the money will just flow if I ever can get started.

I looked at your links. What is a glassdeck? Yes the money be flowing on this project . and I do intend to change out the wheels for something more dot compliant

Nice chassis. Yeah I think the gearbox works well. It was from a 1000kg car so it shouldn't have a problem with a 500kg one.

5 or even 10kw seems light on to me. But then again I am after performance. There is a calculator somewhere to work out the power required to maintain a nominated speed. I highly recommend you find it.

What size would you recommend? I am trying to find a calculator of sorts to figure this out but am having a rough time doing so.

Im torn between these motors can anyone shed some light? which one will yield more power and efficiency for my build?

http://www.ebay.com/itm/Manta-II-10-hp-DC-electric-motor-12-24-48-Etek-Motenergy-Permanent-Magnet-USED-/331610128568

golden motors 5kw water cooled brushless

golden motors 10kw water cooled brushless


im just at a loss as to which one to purchase?

Or what about two hub motors in the back at 5kw each? Would this get the job done?

http://www.qs-motor.com/product/13inch-273model-8000w-electric-car-single-shaft-hub-motor-v3-type/

http://www.qs-motor.com/product/205model-3000w-single-shaft-electric-car-hub-motor50h-v3-type/

Vito Ho from QS Motor is also here on E-S and could tell you better what is best for your project:
https://endless-sphere.com/forums/viewtopic.php?t=65972

This is wonderful! Thank you! Donyou know if people generally have good experience with hub motors? I get the feeling they are weaker than one would usually think

Try this calculator

http://buggies.builtforfun.co.uk/Calculator/index.html

When I try it for mine with the following constraints it tells me 20.6KW at 60mph which sounds about right. My old controller only got me up to about 55mph and I estimate it was producing about 18KW to push my 600KG (car and driver).
Vehicle Weight 61 kgf (Vehicle weight with gravity factor removed because we are talking about horizontal movement)
Vehicle Speed 100 km/h
Coefficient of rolling resistance, Cr 0.1
Angle of climb, 1 in 1000 (Flat)
Drag Coefficient, Cd 1.5
Vehicle Frontal Projected Area, 1 m^2
Air Density 1.2 kg/m^3
Change in speed 0 km/h (Because we aren’t looking for acceleration rates)
Time taken to achieve this speed change 1 seconds (otherwise it seems to zero out the calculation)
Ext Force 0 kgf
Effy 100%

I know these aren't perfectly accurate but we are only after a guide and some of these figures are not obtainable at home.
If I try it with double the weight but leave all the other parameters the same it tells me 22KW

Electric motors are rated on their output over prolonged periods. For me that isn't important I want to be able to ask more of the motor for shorter periods. But for you the output rating does need to be prolonged so I think you should be looking for a total of around 20KW (a touch more if possible).

ok so right now i was looking at a 5kw motor with a 10kw peak, im guessing i need to do at least a 10kw motor which can peak at 20kw? the calculations for my 860 pound buggy (fully loaded with me ) requires 11690 watts to get up to about 68mph. assuming 100% efficiency which of course isnt totally possible. your thoughts? Thank you so much for this calculator ive been looking for something like it !

http://www.qs-motor.com/product/3000w-8000w-electric-car-hub-motor273-model/

If you'd use two of these and only need 10kW of them each at intervals it should be okay. And with ferrofluid or air cooling you could go higher/longer in power. Use the search function of this forum for more info.

this seems like a wonderful idea, although from seeing the forums people tend to not lean torwards hub motors, is there a reason for this?

so good news! I have ordered almost 100ah of chevy volt batteries , i will be running a 48v system now to pick up a motor and controller. i am highly considering hub motors now. i am trying to find the pricing on the ones reccomended above. i am also seeking a chassis donor to get everything mounted on. i am adding a 48v to 12v dropper to help me run 12v stuff. and now i have ordered little details like voltmeters and the electric pedal. so things are starting to come together! lets start the price tally


batteries 770$ so far expected range at 5kw motor for 100ah is 60 miles.

volt meters 12 dollars

now we need motors and the chassis to boot!

so i looked into the hub motors which i really liked but dude to cost its just prohibitive for this build which is sad since a hub motor would open up more space for future batteries. at a cost of over 2400 thats more than the budget of the entire build. although it would leave me at a 16kw motor set.

currently im looking at picking up a golden motor 5kw and mounting it in the middle with a 20kw controller. i am being told i can run this motor at 15kw without any issue. is this the case? if so thats over 20hp which is perfect for the build. thoughts?