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I am still trying to figure out components and my car is space challenged. It looks like a Hyper 9 motor will be the power, I have read that I may need up to 5 18650's. This is not even a weekend driver it is a race vehicle with a VW transaxle. I need as much torque and rpms as I can get for six (6) 90 second runs in an event and some slow driving to and from actual course. Car will be turned off for about 10 minutes between each run. Can I get by with 3 or 4 ? I could stack 5 if necessary.
Hey,
I'll start out by saying I LOVE the Hyper 9, it's a great all around motor, and man does it sound awesome! But if this is a race car and you aren't backed by a fortune, then go DC. I recommend a Warp 9 and zilla z1k for starters, but I don't know your performance targets. The max "rated" voltage on a Warp 9 is 170V, so if you want max power for that motor, you need a pack with voltage probably around 200V. You want a strong pack that is pretty stiff so that under 1000A load, it hopefully will sit around 170V - that's the goal. That will give you 350 ft lbs of torque @ 1000A from 0 to about 2500 or so RPM. You will be making at least 175 HP or so as well with that. Duncan is right, build your car around the battery pack. If you want more power, go with a zilla z2k, but you'll need high performance lithium for that. I would recommend building a custom pack if you're building a race car. Then design the rest of your car around that. I would recommend Kokam 75ah HP (high power) cells. They're rated for 1200A for 10s. I've got an 80S custom pack of those built into 4 modules, with a z1k and warp 9. All in a bug and it kicks butt!

I would recommend elcon 6.6kW charger and elcon 1kW DC/DC converter though, really reliable and great bang for your buck. Let me know if you want some help with planning or sourcing parts, I can help get you the best prices (chargers, motors, controllers, fuses, anything).

Cheers
 

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It's a race car - he's driving it like a girl if it's not crashed and totaled well before needing new batteries, lol.
Well, it's an autocross car... they're rarely crashed, although it does happen. Mostly they hit orange marker cones... and wear out tires. It does take a long time in solo competition like this to build up a lot of operating hours, but cycling is another matter - it's a full cycle every day, with frequent high discharge rates. I wouldn't count on the batteries to be effectively immortal.
 

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Discussion Starter #24 (Edited)
Hey,
I'll start out by saying I LOVE the Hyper 9, it's a great all around motor, and man does it sound awesome! But if this is a race car and you aren't backed by a fortune, then go DC. I recommend a Warp 9 and zilla z1k for starters, but I don't know your performance targets. The max "rated" voltage on a Warp 9 is 170V, so if you want max power for that motor, you need a pack with voltage probably around 200V. You want a strong pack that is pretty stiff so that under 1000A load, it hopefully will sit around 170V - that's the goal. That will give you 350 ft lbs of torque @ 1000A from 0 to about 2500 or so RPM. You will be making at least 175 HP or so as well with that. Duncan is right, build your car around the battery pack. If you want more power, go with a zilla z2k, but you'll need high performance lithium for that. I would recommend building a custom pack if you're building a race car. Then design the rest of your car around that. I would recommend Kokam 75ah HP (high power) cells. They're rated for 1200A for 10s. I've got an 80S custom pack of those built into 4 modules, with a z1k and warp 9. All in a bug and it kicks butt!

I would recommend elcon 6.6kW charger and elcon 1kW DC/DC converter though, really reliable and great bang for your buck. Let me know if you want some help with planning or sourcing parts, I can help get you the best prices (chargers, motors, controllers, fuses, anything).

Cheers

My performance is goal around the 170 to 200 ft/lbs torque and optimally if I could get to 5000 rpm I can get the gearing for my transaxle. It would put me about 60+mph using 3rd gear for small courses and up to 100 easily for when we run at Pocono on the infield road race course. Here is a vidoe of our last set up, not my car a 90's mustang. He could have gone faster.

 

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My performance is goal around the 170 to 200 torque...
"Torque" is not a unit of measure. You presumably mean pound-feet of torque; it would be good to make that explicit, because electric motor specifications are often given in international standard units, which are newton-metres (Nm) for torque. 170 to 200 lb-ft is the same as 230 to 270 Nm.
 

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Discussion Starter #26
"Torque" is not a unit of measure. You presumably mean pound-feet of torque; it would be good to make that explicit, because electric motor specifications are often given in international standard units, which are newton-metres (Nm) for torque. 170 to 200 lb-ft is the same as 230 to 270 Nm.
Ahh thanks for that, being American any torque reference is always been only ft lbs.
 

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Discussion Starter #27
My compartment is 32" from motor side of trans-axle to fire wall behind seat. 19" wide and deep but it tapers down to 12" wide at lower frame. I could widen the mid section since the sides are just fiberglass panels. It also enable me to fit a better seat. Right now pretty much am lying on floor in a half ass fiberglass bucket chair, no side support at waist and definitely nothing in side and shoulder areas.
120023
 

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I'd chuck the transaxle and hang a Tesla drive unit off the back to make room you desperately need for batteries.

As is, I can see getting 6 Model S/X modules in the compartment, 33kWh, ~300V with slicing & dicing. Eyeballing, maybe one more module on top, so 350V, 38kWh, 375 lb of battery roughly.

You'll get around ~200HP out of it, maybe.

Without slicing and dicing the modules, you get half the voltage, double the current. Maybe a DC motor running the transaxle upside down or use a Bug transaxle.
 

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Tesla modules are not a good idea - too heavy for the voltage
Or more accurately they are designed for range - 250 miles - in a big car
You are looking at 30 miles in a small car!
 

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"Produces a massive 400 Torques" used to always bug me on Top Gear
I bothered me, too, until I accepted that Top Gear is not an automotive enthusiast's show - it's comedy in cars. The hosts (of any vintage or variation of the show) are shockingly ignorant of automotive technology.
 

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I'd chuck the transaxle and hang a Tesla drive unit off the back to make room you desperately need for batteries.

As is, I can see getting 6 Model S/X modules in the compartment, 33kWh, ~300V with slicing & dicing. Eyeballing, maybe one more module on top, so 350V, 38kWh, 375 lb of battery roughly.
As undesirable as it would be to put a huge mass out beyond the rear axle, this idea does have some appeal, just for ease of mounting both the drive unit and centrally-located battery modules.

Without slicing and dicing the modules, you get half the voltage, double the current.
I assume that you mean with half a set of modules in stock form you get half of the full pack voltage and the same current capacity as stock, which is twice as much as the modified modules. And this is less than half a Model S or X module set, which was 14 modules in older/smaller packs and 16 modules in current packs.
 
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