# ekarts



## dladd (Jun 1, 2011)

I took a quick day trip over to Sonoma Raceway (Sears Point) yesterday to watch some ekarts on the track (this was on the Kart track, short and tight, not the main road course). It was a regular karting day, so 8 classes of racing. a hundred or so 2-stroke karts, and 7 electric which got their own class. It was cool to see and talk with the builders/racers, quite a range of e-karts were there, ranging from 48v DC, to 120v AC power. All powered by Lithium chemistries of one type or another. I took pictures of a few of them:

This first one was over by the registration building plugged into an outlet when I saw it, didn't talk with the owner. It appears to be DC with an Alltrax controller, and a Zero motorcycles battery pack (that's the white box on at the top right of the photo, other side of the kart). That's about all I know... 










This next one was my sentimental favorite build, since it has the same cells (just a bit smaller) that I have in my car.  It was running ~80v through an AC motor of some kind. It is based on a smaller Kart with no front brakes (I don't know karting well, not sure what the class structure/definitions are). I did hear him ask one of the faster guys not to pass and brake check him into a corner since he can't stop it as well. 










This third one looked wicked! It's physically larger, front brakes, and is running an AC-15 motor. You can see he's got a forced air blower on the motor, and a water cooled chill plate on the controller going to that radiator on the back. I do not remember the exact voltage or type of cells, but they are LiPo, and he had an extra set of battery packs for quick swapping. The batteries are mounted on adjustable mounts so he can fine tune the front/rear weight bias. Cool setup, but in talking to him it sounds like it's too heavy to really compete right now.










And below is the fastest one. He easily won the race, I hear he set a top speed record of almost 90mph on the front straight. Some of the gas karts were a little quicker around the track, chalk it up to the weight difference. This kart is powered by ~120v of LiPo going into an AC-20. You can see it's got a blower on the motor, the controller only appears to have a heat sink, no active cooling. Very impressive kart.










Cool stuff.


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## Ziggythewiz (May 16, 2010)

That CALB Kart looks awesome.


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## winzeracer (Apr 3, 2012)

Looks like a good time, I will have to make a trip up north when I finish my kart. Progress is slow right now, but it looks like I might have 3 packs for hot swapping, it looks like all these packs are fixed. I will have to shoot Brian @ Thunderstruck an email and see when they meet up. Thanks for the post and the pics!!

EDIT: I see that the orange pack is swappable.


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## Karter2 (Nov 17, 2011)

> .. It was running ~80v through an AC motor of some kind. It is based on a smaller Kart with no front brakes (I don't know karting well, not sure what the class structure/definitions are). I did hear him ask one of the faster guys not to pass and brake check him into a corner since he can't stop it as well.


 Hmm ? .. I am a keen karter and an EV enthusiast, but i could not enthuse over someone running a fast heavy kart like that with out effective brakes.
Most fast ICE kart classes only run a rear brake,... but they do not have to slow down an extra 50 kg of battery .
Good brakes are just as important as good motors and good cells when it comes to performance ...and safety !


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## jeremyjs (Sep 22, 2010)

NVM. Miss-read.


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## Arlo (Dec 27, 2009)

Very cool! One more step in batteries and this sport will take off for sure!


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## winzeracer (Apr 3, 2012)

I should be lighter than these guys at just under 400lbs and I will definanlty be adding front brakes to my kart!


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## Arlo (Dec 27, 2009)

winzeracer said:


> I should be lighter than these guys at just under 400lbs and I will definanlty be adding front brakes to my kart!


 Only the VERY uber fast (Shifter) ICE karts use front brakes all others simply dont need it!


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## winzeracer (Apr 3, 2012)

Arlo said:


> Only the VERY uber fast (Shifter) ICE karts use front brakes all others simply dont need it!


But they dont have a shit ton of LiPo strapped to them either


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## Arlo (Dec 27, 2009)

winzeracer said:


> But they dont have a shit ton of LiPo strapped to them either


 True lol but in karting you will only want to carry what you need for batteries any extra makes you slower and wastes power and makes the motor hotter etc.


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## winzeracer (Apr 3, 2012)

So you think i should test before adding front brakes? I will have 3.3kwh of energy, my heavier pack is 65lbs lighter pack is 55lbs. Good news is I have lost 25lbs since build started!


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## Arlo (Dec 27, 2009)

winzeracer said:


> So you think i should test before adding front brakes?


I would. Adding weight means you need more batteries then you add more weight and its a vicious cycle. lol


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## Karter2 (Nov 17, 2011)

Arlo said:


> Only the VERY uber fast (Shifter) ICE karts use front brakes all others simply dont need it!


 Well thats how it used to be, ...but not true these days Arlo.
Most of the top level 125cc classes ( inc TaG, Rotax, KF, ,etc ) use front brakes now,..often operated by a separate hand lever on the steering wheel !...so they have independent front and rear brake control.


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## Arlo (Dec 27, 2009)

Karter2 said:


> Well thats how it used to be, ...but not true these days Arlo.
> Most of the top level 125cc classes ( inc TaG, Rotax, KF, ,etc ) use front brakes now,..often operated by a separate hand lever on the steering wheel !...so they have independent front and rear brake control.


 Top level.... Thats what I said uber fast top level = same thing...


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## Karter2 (Nov 17, 2011)

Arlo said:


> Top level.... Thats what I said uber fast top level = same thing...


 Ok, i will rephrase... The regulations have changed in the last few years and now front brakes are common in most classes of competition karts,.. where as previously they were only found on the "Shifter" classes.


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## tomofreno (Mar 3, 2009)

Thunderstruck was one of the early dealers for HPEVS. I talked to the owner in 2008 when I was looking into converting since he had converted a metro with an AC31. They also do a lot with motorcycles.


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