Gokart 7.90 1/8 mile

[howler45723]

Hello ALL,

I am trying to get a gokart to achieve 7.90 1/8 mile @ 600 lb, I would like you suggestions on motor type, controller, Batteries\ configuration. I can use up to 144 volts. I believe the motor needs to spin at least 5500 - 6000 rpm. Batteries will need to be lite,sealed,and around 50 lbs. ( cost needs to be around 1500 - 2000 dollars )

Thank you
Mike
terawattracing.com

[zombiess]

You would need to generate about 65 HP or have one hell of a 60' in order to do a 7.90 1/8 mile @ 600lbs.

Why is your kart going to weigh 600lbs? I don't see how this power level could be achieved for the costs you are talking about or even 4000 unless you are given stuff for free.

Your controller and battery would have to be capable of over 339A @ 144V to generate the necessary 49KW ~65HP. This isn't even taking into account drive train or electrical losses. Your expectations seem unrealistic.

This site should give you some calculators to at least give you a rough idea what you are up against. http://www.wallaceracing.com/Calculators.htm

If you get down to around 350lbs race weight then you only need about 40HP to achieve your goal. Still quite lofty though.

[liveforphysics]

Two Agni 95r motors, tiny nano-tech pack. 800amp controller per motor, running a 100v pack. Total 150lbs kart weight. Get the lightest driver you can find.

I estimate about $2500 in motors, about $1000 in controllers, about $1000-1500 in batteries.

[howler45723]

zombiess/ livefor physics
Thanks guy's
my cart less driver has to be under 400 lbs, around 200 lbs less drive sys, i guess i added a little too much for motor and batteries. my ideal hp would be at least 45 +, ideally 47 - 48.. i am limited to 1 drive motor. thanks for any and all help with part numbers and suppliers.

Thanks again
Mike
terawattracing.com

[liveforphysics]

You can burst 45hp from each Agni motor for the 8seconds your pass is going to last. They are 24lbs each, and you only need a small sprocket and chain and a 3lbs bracket to mount each one.

http://www.electricmotorsport.com/store ... i_b95r.php

A controller like this, with the motors powered by it in series would work well for your 8second bursts.

http://kellycontroller.com/kdh14800d24- ... p-742.html

Then you want to run this 5s pack 8 in series, for a total of 40s input to that controller. It will be 148v nominal voltage, does your 144v class rules allow that much fudge room? Otherwise you buy 6s packs of the same series cell and run them 6 in series.
You will want to run those packs 3p, which will average about 50-60C discharge on the cells, and keep them happy.

So, that means buying 24 of this pack:

http://www.hobbyking.com/hobbyking/stor ... _Pack.html


Now buy a light Kart chassis on craigslist. Get a non-shifter kart, like a rotax-max series kart chassis, because you don't need the front brakes and extra linkage and crap.

That above formula will reach your desired goals.

[Arlo1]

Cool thread. I have plans for some fun kart stuff. I have a kart motor like the one in the 70,000 watt kart. I have a deal on a altrax 300amp 48v controller for now and I will either build a couger controller or fix a couple I have been offered to fix and have for cheep. I am building this with the kids in my little dun buggy it should weigh ~100lbs when done depending on batteries right now the kart weighs ~ 50lbs as a rolling chassis. And I have to weigh the motor but there is no way I will be over 400 lbs kart and driver. We will be running lots of things in the 1/8th incl a electric bar stool we just built and a s10 drag truck we will be building over the next few years.

[Arlo1]

Looks like I will have to weigh everything... Garriels Kart http://www.evalbum.com/1205 weighs 400lbs without driver But I am planing to use cheep tunigy lipo... And I will not have as much weight in batteries for a 1/4 or 1/8 mile run.

[Jay64]

Luke, it sounds like he can't run the dual Agni setup, as he stated he is limited to 1 drive motor.

[zombiess]

You can burst 45hp from each Agni motor for the 8seconds your pass is going to last. They are 24lbs each, and you only need a small sprocket and chain and a 3lbs bracket to mount each one.

http://www.electricmotorsport.com/store ... i_b95r.php

A controller like this, with the motors powered by it in series would work well for your 8second bursts.

http://kellycontroller.com/kdh14800d24- ... p-742.html

Then you want to run this 5s pack 8 in series, for a total of 40s input to that controller. It will be 148v nominal voltage, does your 144v class rules allow that much fudge room? Otherwise you buy 6s packs of the same series cell and run them 6 in series.
You will want to run those packs 3p, which will average about 50-60C discharge on the cells, and keep them happy.

So, that means buying 24 of this pack:

http://www.hobbyking.com/hobbyking/stor ... _Pack.html


Now buy a light Kart chassis on craigslist. Get a non-shifter kart, like a rotax-max series kart chassis, because you don't need the front brakes and extra linkage and crap.

That above formula will reach your desired goals.

Thanks a lot Luke, you might have just given me the formula for someones early death. A 200lb motorcycle (probably a dirt bike frame setup as a motard) with 2 of these motors and this setup should come in under 400lbs total. Assuming you burst 80HP through the dual Agni setup it's a low 10 sec@130mph 1/4 mile ride. Sounds like one really fun commuter too.

A Yamaha TW200 (stock they dyno 13HP and 9ft lbs of torque) with just 1 of the Agni 95's would be an absolute blast to ride around, 2 a total death trap, though but what a blast! I could just imagine the looks on a squids face as his brand new GSXR600 got left from a dig by a tiny balloon tired mini monster. I need a higher paying job.

I've also caught myself looking at some of the clone street legal (DOT) Chinese pit bikes which can use commonly available parts. Sell the motor off and put this in it.

[howler45723]

WOW, great stuff you guys are way ahead of me, I was looking at some forklift motors, lots of torque and 5500 rpm, what do you think about these batteries

EnerSys Genesis Pure Lead XE16 24v 15 lbs. ea

our class is 144v, but can read at batt 158v at meter

thanks again for all your suggestions and knowlege

[Arlo1]

You might be able to get more performance from a 6.7 inch fork lift motor like this one
For a lot less money zombies. I got mine for free and cost me $20 to rebuild it with new brush wire and new bearings and an added cooling fan! I will weight it later. But im guessing 30-35lbs

[howler45723]

NICE, I cant stop hitting the play button

[zombiess]

WOW, great stuff you guys are way ahead of me, I was looking at some forklift motors, lots of torque and 5500 rpm, what do you think about these batteries

EnerSys Genesis Pure Lead XE16 24v 15 lbs. ea

Garbage. You want performance which means high amps and light weight, not a UPS system for a server rack. Lead is anti performance.

[liveforphysics]

WOW, great stuff you guys are way ahead of me, I was looking at some forklift motors, lots of torque and 5500 rpm, what do you think about these batteries

EnerSys Genesis Pure Lead XE16 24v 15 lbs. ea

our class is 144v, but can read at batt 158v at meter

thanks again for all your suggestions and knowlege

Worst possible battery choice on earth for drag.

[zombiess]

Worst possible battery choice on earth for drag.

I disagree with you Luke, these batteries are perfect to drag down the performance of an electric vehicle.

[howler45723]

Nice
EV humor, IT humor cubed

I guess i'm looking for the holey grail lite, powerfull ( for 8 seconds ) cheap

[zombiess]

Cheap, fast or reliable. Pick two.

[winzEracer]

Cheap, fast or reliable. Pick two.

This is true, I am also building a crazy ekart with the new Agni 111r from Jozzer, just got it in the mail. Not cheap but defiantly a mean small 26 lb motor, I am pairing it with a Soliton Jr and turnigy nano tech( I think) check out my website www.winzeracer.com, which also has a link to my thread at Diy Elec Car.

Have you made any progress on this?

Brock
Www.winzeracer.com

[John in CR]

WOW, great stuff you guys are way ahead of me, I was looking at some forklift motors, lots of torque and 5500 rpm, what do you think about these batteries

EnerSys Genesis Pure Lead XE16 24v 15 lbs. ea

our class is 144v, but can read at batt 158v at meter

thanks again for all your suggestions and knowlege

Worst possible battery choice on earth for drag.

Depends how you use the word drag. If you strap one to the ankle of every politician, lawyer and investment banker, and then toss them in the ocean to drag them to the bottom it's the best possible battery choice. OTOH concrete would be better and less toxic.