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67LS1
67LS1 Reader
2/21/22 1:48 p.m.

As more and more Teslas end up in wrecking yards, I'd like to see a pre-engineered rear clip that would accept the Tesla motor/rear suspension that could be grafted to existing 50's-70's full frame car chassis.

And a battery pack in a form factor that would occupy the space originally occupied by the original engine/transmission. Possibly to use the stock radiator location to install battery cooling systems.

I'm not a fan of a front mounted electric motor turning a driveshaft to a traditional rearend.

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
2/21/22 2:37 p.m.

I like the idea of a bolt-in motor setup, but it would end up being platform-specific. Like A-body, B-body, etc. I'm picturing the equivalent of a Ridetech suspension package, but with a motor in the middle. Given that would be an IRS conversion at the same time, I wonder if you could do it without involving sheetmetal surgery?

I want to see someone package a motor in a straight axle and make it available. Probably wouldn't be a junkyard part but that's your old school hot rod retrofit. Such things already exist to some extent but I think they're either extremely weedy or monstrous as they're built for either tiny delivery trucks or real trucks. It's possible the new Ford Transit EV might give us some interesting parts here, although it's not a stick axle.

A battery pack in the form factor of a SBC would make a lot of sense if you can get enough cells in there. Maybe a BBC :)

APEowner
APEowner GRM+ Memberand SuperDork
2/21/22 3:04 p.m.

I keep wondering if there's a market for a modular battery system with mounts, interconnects and a distributed processing, battery monitoring control system that would allow one to easily stack modules in whatever directions are needed to fit in the available space.

 

Oapfu
Oapfu GRM+ Memberand New Reader
2/21/22 5:38 p.m.

In reply to APEowner :

Dennis Palatov thinks so, ref. the EBF (Extendable Battery Framework) from Modular Battery Technologies, Inc. (a.k.a. ModBatt)
And there are a metric boatload of other companies also working on standards, and/or products they hope become the de facto standard.

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
2/21/22 6:09 p.m.

Looks like Palatov is basically taking a bunch of small cells and packaging them into a single brick. Cooling is still left as an exercise to the installer, but it's got some communication abilities so it can talk to the other product, a BMS. I think to make them truly modular so they could be mounted in any possible configuration in the way APEowner is thinking, they'd need integrated water cooling in each module. Maybe you could strap a couple of radiators on the faces of that module.

I know the Tesla and Leaf packs are made of modules of cells, similar to the ModBatt concept.

https://057tech.com/products/battery_modules

The new GM Ultium batteries are similar with an interesting twist of wireless cell communication to cut down on a significant amount of wiring.

https://chargedevs.com/newswire/gm-reveals-more-technical-details-of-its-ultium-battery-packs/

I don't know how the Tesla or GM batteries get cooled.

 

MrJoshua
MrJoshua UltimaDork
2/21/22 7:03 p.m.
Keith Tanner said:

 

I want to see someone package a motor in a straight axle and make it available. Probably wouldn't be a junkyard part but that's your old school hot rod retrofit. Such things already exist to some extent but I think they're either extremely weedy or monstrous as they're built for either tiny delivery trucks or real trucks.

I like that concept, but in place of the transmission instead of the driveshaft. (might be what you were saying). The motor size needed is about right for whats used to quickly propel a car.

A few people have repurposed Lexus RWD hybrid/motor filled transmissions, but Toyota makes it tough to use with other controllers because they wind it for higher voltages and use a boost converter to raise the voltage of the pack. 

Chevy made a nice powerful dual motor trans they shoved in Tahoe hybrids, but the vehicle never sold well and was failure prone so its a pretty terrible donor. 

 

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
2/21/22 7:14 p.m.

In reply to MrJoshua :

I want it in the place of the differential. Like the Magna eBeam.

wheelsmithy (Joe-with-an-L)
wheelsmithy (Joe-with-an-L) GRM+ Memberand PowerDork
2/21/22 8:16 p.m.

Vaguely interesting video on running ancillaries 

 

67LS1
67LS1 Reader
2/21/22 10:56 p.m.

That Magna eBeam is awesome. Although I like Keith's idea of IRS so the motor wouldn't be bouncing around.

rob_lewis
rob_lewis UltraDork
2/22/22 12:53 p.m.

Lots of good questions in this thread and I'm probably repeating a few.  For me, it's a few things:

  1. What options are out there other than Tesla's?  They're just so expensive right now in the junkyard
  2. Has anyone/can you swap different components?  I.E. Tesla battery and a Leaf motor.  If so, what things do you need to be aware of?
  3. How DIY is this really?  I'd love a classic with an EV, but the limited research I've done seems to be crazy complicated and/or crazy expensive.
  4. Is there a basic schematic/design that someone could start from and build from there?  I'm totally cool with blazing a trail, but literally don't know where to start.
  5. What non-automotive options are there?  What other industries are electrified that someone cobble up parts for?  Can a home battery storage unit be converted?  Is there an industry where battery weight is more critical than a car? 
  6. Everybody points to the instant torque and performance, but are there ways to reduce that?  Instant torque can cause massive wheelspin.  Is there anyone making some type of torque limiting for initial roll on that increases as speed does?
  7. Power is fun, but how do you limit power for just cruising or saving battery life? 
  8. What cars should I mark for notification at my local pick and pull?  :D

I just saw this vid and it checked soooo many boxes for exactly what I'd want, I came back to this thread to ask my questions.  Classic car?  Check.  Original looking? Check. Decent range? Check.  Still usable space?  Check.  Oddly, it's less about the performance for me.  I'd happily sacrifice a bit of the 0-60 for a bit more range. 

https://www.youtube.com/watch?v=fKWe1R1bWOM&list=WL&index=56&ab_channel=PetrolPed

-Rob

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
2/22/22 1:20 p.m.

The 0-60 comes as a byproduct of range to a large extent. Big batteries and efficient motors will accidentally give you lots of torque.

"Power is fun, but how do you limit power for just cruising or saving battery life? "
Every car has an accelerator pedal, and they're usually equipped with positions between 0 and 100% :) That is how you limit power for cruising.

Telsas are the LS engine of swaps: plentiful and powerful. As more cars come to market and end up in junkyards, more options will become available. But right now, it's basically Tesla followed by Leaf and Bolt.

For the EV 101, check aemev.com. There are some good videos in there that go over the various systems at a high level. And yes, you can combine batteries from one car with a motor from another.

rob_lewis
rob_lewis UltraDork
2/22/22 3:38 p.m.
Keith Tanner said:

The 0-60 comes as a byproduct of range to a large extent. Big batteries and efficient motors will accidentally give you lots of torque.

"Power is fun, but how do you limit power for just cruising or saving battery life? "
Every car has an accelerator pedal, and they're usually equipped with positions between 0 and 100% :) That is how you limit power for cruising.

OK, I'm stupid.  I'll fully admit it.  I've never driven an EV (unless a golf cart counts!! :D ) so I'm kinda guessing here on what I've read over the past few years.   EV's talk about "instant torque".  So, if your electric motor has 100 ftlbs at 1 rpm or 1000 rpms, you could light up the tires regardless of how far you push the pedal.  I assumed the pedal only determined how fast the motor would spin, not how much power.  Whereas on ICE, torque increases with rpms.  If I apply 10% throttle on an ICE, I'm not getting 100% of torque (thereby, potentially overcoming traction), but if I apply 10% throttle of an EV, aren't I getting 100% of torque?  I'm probably totally wrong on that. 

To take that to my cruising comment, if torque is available at 1 rpm, what does the accelerator do in regards to power?  If I'm understanding it, unlike an ICE, you don't get more power (ok, maybe just torque, perhaps you get more HP) at higher rpms.  If power stays the same and only the rpm's change, what is the variation of draw on the batteries?  Does battery drain increase with rpm's?  So, if you're turning 1000 rpm's are you using half the charge of turning 2000 rpm's?  If so, then why wouldn't a transmission that adjusts the rpm's depending on speed help with the battery usage?  Again, from what I've read, if you're converting an old car and still connected to an ICE transmission, you just leave it in 4th the whole time because changing gears doesn't make a difference (or the difference is minuscule). 

It's probably covered in the link you sent and I will check it out when I have some time, but wanted to explain why I asked such a goofy question.  I know I'm stupid when it comes to this stuff, so I feel OK with asking here.

-Rob

Keith Tanner
Keith Tanner GRM+ Memberand MegaDork
2/22/22 4:06 p.m.

Think of the EV accelerator pedal (technically it's not really a throttle anymore, is it?) as being like an ICE throttle at a given RPM. 10% throttle is 10% torque delivery (roughly), 50% is 50%, 100% is 100%. What happens with an ICE is that 100% moves around. 100% torque at 3000 rpm might be quite different than 100% torque at 6000. With an EV, that 100% stays more consistent. Otherwise, it behaves just the same. 10% throttle is 10% torque.

The motor in an EV isn't an on-off thing like hooking up a 9V battery to a motor you ripped out of an old Walkman. To oversimplfy, think of your accelerator as a dimmer switch that determines how much power is sent to the motor. It's not quite in that form, but if you think of it as a dimmer switch you'll probably get the idea. I honestly don't know if golf carts work this way, it wouldn't surprise me to find out they basically just have an on-off switch for a throttle.

When you're cruising, you manipulate the power delivery to balance the drag. Some of that gets lost in inefficiencies, but it's all about finding that point. The question with transmissions is if you can cut down those inefficiencies, and if it's worthwhile. So far, Porsche says yes and everyone else says no. There's also torque multiplication if you need a large amount of torque available, like low range in a rock crawler. Seems easier in most cases these days to just spec a bigger motor.

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