Electric KOH and Desert Builds - Technical Discussion

Wicked Al

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Do any of the other KOH EV platform builders have builds going on that are posted online anywhere? Would be great to follow along if anyone has links.
I would be interested in this too. All are welcome to post their builds on this thread too if they want.
 

Wicked Al

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would a 2wd electric drag bike be feasible?
I’m not a drag racer, but I would expect that a 2wd drag bike wouldn’t make a heck of a difference considering all of the weight transfer to the rear tire. On the other hand, it should make a smidgen of a difference which may be all someone is searching for. It WOULD be interesting to design for it.
 
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pyrocoyote1

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i was looking up how to modify tesla batteries and there is not much information about it. but i was thinking in therory if you could cut the exoskeltion off the battery structure(like the model3 or s battery), and arrange the cells into a more linear configutation so it is not as wide. then fabricate a housing that bolts on the bottom of the cage. i would have the charge port be connected to the battery not the frame. and have one quick connection cable that would go to the dual eletrict motors. so if you need to do a battery change, disconnect the one power cable have a quick disonnect bracet that would drop the floor pan battery. then push the car( which will be about a 1000lbs lighter) forward and have the other battery charged ready to go on a jack, roll it under the car, jack up the battery until the floor pan battery locks in place and connect the single cable and go.
the battery that you just took off the car could be charged with a genorator in the pit if you need it in a longer race.


i know you want 4 motors but you really might not need them the added weight and complexity and ampreage draw might hert your range in the long run. imho.
ps love this thread.
 

Wicked Al

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i was looking up how to modify tesla batteries and there is not much information about it. but i was thinking in therory if you could cut the exoskeltion off the battery structure(like the model3 or s battery), and arrange the cells into a more linear configutation so it is not as wide. then fabricate a housing that bolts on the bottom of the cage. i would have the charge port be connected to the battery not the frame. and have one quick connection cable that would go to the dual eletrict motors. so if you need to do a battery change, disconnect the one power cable have a quick disonnect bracet that would drop the floor pan battery. then push the car( which will be about a 1000lbs lighter) forward and have the other battery charged ready to go on a jack, roll it under the car, jack up the battery until the floor pan battery locks in place and connect the single cable and go.
the battery that you just took off the car could be charged with a genorator in the pit if you need it in a longer race.


i know you want 4 motors but you really might not need them the added weight and complexity and ampreage draw might hert your range in the long run. imho.
ps love this thread.
No two ways about it, the battery will be a challenge to configure it in a way that works and is flexible.

One electric motor with a traditional drivetrain is a generation 1 design, this is a generation 2 design and needs each wheel individually powered (so have I named it, so shall it be). There are performance benefits to be had for a generation 2 design. The motors are fairly light energy dense motors, I like the pros vs the cons.
 
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ElectricYota

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I dig this thread Alex thanks for makin it.

Here’s the thread I had on diyelectriccar.com, it had been dormant for awhile I just threw some pics on it.


My team and I plan to keep racing as much as possible. Our team just got bigger with the addition of Keith, he’s build a KOH racer using a Tesla large drive unit swapped into his old s10 crawler. One tons fully linked with coilovers. Hoping it will make its debut next month at Holley High Voltage
 

Wicked Al

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can the battery packs be smaller, just have 4, 6 of them instead of one big monster battery pac?,
I think that is a likely outcome. The BMS has to balance the charge and discharge of each individual cell…but, each pack is made up of cells both in series and parallel, so why can’t those parallel groups be grouped in smaller packs? It’s a programming issue I believe…but not sure.
 

jon coleman

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i would put a bank of crew member manageable, 150lbs,each, battery packs in ballistic encasements along each side, with a seal tight lid, at, like a 45 or so degree angle to also act as rock sliders along the lower rockers, use some 3/ 16 cro mo, with a1" or 2 crush / buffer zone, pull into pits, pop lid, pull out the 4 packs on each side, or which ever ones are ' empty', slide new ones in, close top& latch, done
 
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Wicked Al

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I dig this thread Alex thanks for makin it.

Here’s the thread I had on diyelectriccar.com, it had been dormant for awhile I just threw some pics on it.


My team and I plan to keep racing as much as possible. Our team just got bigger with the addition of Keith, he’s build a KOH racer using a Tesla large drive unit swapped into his old s10 crawler. One tons fully linked with coilovers. Hoping it will make its debut next month at Holley High Voltage

Thanks Kyle for connecting with us here. It’s great to have someone with actual experience in the mix rather than folks (like me) who just have a lot of ideas.

Have you heard what the status is of the other teams that received EV Crate packages? What are you doing with yours? Would love to know as long as it doesn’t divulge any speed secrets…though I’m not against that either. :D

Here are the teams who received the KOH EV packages. Any links to other threads…anyone?

Teams:
Kyle Seggelin
Bailey Campbell
Casey Gilbert
Duane Garretson
Chip McLaughlin
Jacob Versey
Josh Smith
Robert Taylor
Jon Schaefer
John Grounds
Baker Fabrication
 

Wicked Al

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i would put a bank of crew member manageable, 150lbs,each, battery packs in ballistic encasements along each side, with a seal tight lid, at, like a 45 or so degree angle to also act as rock sliders along the lower rockers, use some 3/ 16 cro mo, with a1" or 2 crush / buffer zone, pull into pits, pop lid, pull out the 4 packs on each side, or which ever ones are ' empty', slide new ones in, close top& latch, done

Figure 12-14lbs per kWh. Need BMS connectivity in addition to a solid IP67 or better pos/neg for the juice. As you suggest, damage control is a must. 150lbs would be a 2 person crew for battery swap. I want to design for one person. Requires more packs, but my goal is to also make it doable for the consumer. The EV Crate package is 40kWh which means the course should be set up to allow that before you need to swap back in the pits. Don’t want to over design, definitely don’t want to under design. We’ll take our best first guess then testing will tell us where we really need to be.

Ford Lightning is about 500kWh per mile at 70-75mph. Reasonable to expect a lighter weight vehicle going over tougher terrain at a slower speed will consume the same? This is the initial number I’m working with.
 
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