Keith Tanner
Keith Tanner MegaDork
11/8/19 6:34 p.m.

Just back from SEMA, and there was some EV action. Not as much as you'd think, because the performance industry doesn't know what to do with them yet. The lowering spring and giant wheel industry has, but they'll chase the next shiny thing next week.

I saw the following:

- a Mustang with a modular battery pack design (good) and a cool axial flux motor (good). But it was bolted in place of the ICE and running through a manual trans.
- a proposed modular motor from GM that can be stacked with up to three units and has an LS bellhousing bolt pattern.
- a Delorean with a custom motor between the rear wheels and a Leaf battery pack. 80 mile range.

I'm sure there were more. I just didn't see them on my casual, non-directed strolling around.

I feel that simply putting an electric motor in place of an ICE and leaving the rest of the drivetrain in place is the easy but lazy button. It shows a lack of effort. I'll accept it in the Mustang if the goal was to test the rest of the tech without having to come up with a gear reduction setup and a way to deal with torque distribution. The Mustang was really a test mule for one subset of the tech.

The modular motor is less compelling. It's an attempt to make EV swaps as easy as an LS swap, but will they be effective in any way other than as a static show piece?

It was the Delorean that impressed me most with the implementation, but with an 80 mile range it brought up other questions. I expect a Tesla swap to be the "LS" of EV swaps for the near future, as it's the only really powerful option that's out there in any numbers. If you go to the effort of a Tesla swap now, will it be compelling in the future or will it be a little embarrassing like the DMC? With modular batteries (both future Webasto and junkyard Tesla ones), range is simply a matter of jamming more batteries in the car. Performance is mostly a matter of ponying up for a Tesla motor instead of one from a 500e. Have we reached the point where a current EV swap will be effective for a few years, or do you think the tech will take a significant step forward and leave any current swap looking weedy?*

 

* yes, yes, there's always some magic battery being proposed. Figure it takes at least 5 years to get out of the lab and another 5 years to end up being a viable DIY build candidate.

stafford1500
stafford1500 Dork
11/8/19 6:44 p.m.

One co-worker has successfully jammed a Tesla drivetrain into an aircooled Porsche 911 body. It sounds odd, but is quite fast and it is used as a more or less daily driver.

The tech and ability is out there, just need more people to mess with it.

Thanks for summing up both the EV and CARB/EPA/aftermarket front from SEMA.

Keith Tanner
Keith Tanner MegaDork
11/8/19 6:51 p.m.

I have an idea for a Tesla-powered Miata that would be pretty compelling...now. Would it be weak sauce five years down the road, or would it be more like our V8 ND? That car has been around for over three years now and is still very much current, even if it does use an old motor.

Robbie
Robbie MegaDork
11/8/19 7:05 p.m.

As something to drive, it'll still be compelling. 

As something called a "car", it'll be weak sauce agaisnt cars that drive themselves and make money for their owners when the owners aren't using them.

Keith Tanner
Keith Tanner MegaDork
11/8/19 7:11 p.m.

I'm thinking more of the 5-10 year horizon, not the distant future :)

Robbie
Robbie MegaDork
11/8/19 7:17 p.m.

Me too ;)

MrJoshua
MrJoshua UltimaDork
11/8/19 7:19 p.m.

Tesla Miata would be a lot like your V8 cars-ridiculously fast enough that a few years won't make it uncool.

dculberson
dculberson MegaDork
11/8/19 9:25 p.m.

A Tesla motor is powerful enough that it will not feel slow in our lifetimes. The rest of the tech might feel dated. But the swap itself will stand the test of time.

Keith Tanner
Keith Tanner MegaDork
11/8/19 9:44 p.m.
stafford1500 said:

One co-worker has successfully jammed a Tesla drivetrain into an aircooled Porsche 911 body. It sounds odd, but is quite fast and it is used as a more or less daily driver.

 

Forgot to mention, there was one of those at the show as well. I think it was EV West in an RWB? There was an enormous amount of room under the engine hood. The batteries must have been up front.

Rons
Rons Reader
11/8/19 9:45 p.m.

In reply to Robbie :

It can't make much money for you if you want to use it at high demand times.

Eurotrash_Ranch
Eurotrash_Ranch New Reader
11/9/19 12:56 a.m.

There is a big, semi-documented "chevy bolt  swap into a vanagon" thread on that big VW/Vanagon website (named after a latin dance) now. Having never given much thought to EV's, this and your Tesla thread have piqued my interest.

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
11/9/19 2:46 a.m.

I was thinking: between this thread and Keith's EPA/CARB thread... that going to an EV race car is going to the thing to do before too long.

I think as long as you got AC motor, with a big enough maximum amperage capacity, that batteries/inverters are where the big changes are mostly going to be.  The rate of change of electric motor output is slower, in part because of how long they've been made... although they've primarily been designed/used in 'constant power' applications... whereas vehicles are much more 'variable power' applications.

As such, the motors have a limited number of areas of improvement directly related to that:  cooling, and weight.

Similarly, the inverters/controllers are relatively straight forward... but have some improvement to account for cooling, and the accel/deccel or generate/regenerate, modes of operation.

Batteries/PotentialEnergyStorage though is clearly where the most room for improvement is going to be had in the short-term.  Both energy density, chemistry, and cooling.  Fortunately these things could ... or should ... be fairly modular.  So, select a good motor, and a good enough inverter/controller, and the batteries you can afford.

The batteries can be viewed like a 'wear item' that would cover the cost of fuel and engine rebuilds required in other performance applications.  The inverter cost to upgrade is more along the lines of header/intake/cams... you budget for it when adding those parts has developed to the point where spending the money provides the right gains.

standard caveats:  my analogies could be wrong, ymmv, caveat lector/emptor, this is just my opinion, etc ad nauseum.

NickD
NickD PowerDork
11/9/19 6:50 a.m.
Keith Tanner said:
stafford1500 said:

One co-worker has successfully jammed a Tesla drivetrain into an aircooled Porsche 911 body. It sounds odd, but is quite fast and it is used as a more or less daily driver.

 

Forgot to mention, there was one of those at the show as well. I think it was EV West in an RWB? There was an enormous amount of room under the engine hood. The batteries must have been up front.

EV West has an EV-swapped E36 that is absolutely mental

NickD
NickD PowerDork
11/9/19 6:51 a.m.
Rodan
Rodan Dork
11/9/19 8:28 a.m.
sleepyhead the buffalo said:

I was thinking: between this thread and Keith's EPA/CARB thread... that going to an EV race car is going to the thing to do before too long.

 

I just wonder how this is going to work, given current battery tech...  let's say you're running a typical race/HPDE weekend, say four 20 minute sessions followed by a 30 minute race each day for both days, Saturday and Sunday.  So that's 100 minutes of track time each day, assuming running full sessions, and needing the best power availability at the end of the day for the race.

Obviously, the best scenario is swappable battery packs, but now you need the equipment to do it in the pits, and batteries are heavy, so smaller modular packs would be best.  Either way, they still need to be charged in the pits... until tracks install charging infrastructure, how much generator do you need to keep up with the power use?  And you'll need to carry fuel for the generator.

I'm not really opposed to electric performance... I went through the transition from fuel to electric in RC aircraft over 10 years ago, and there are definite benefits.  But it was easy to carry a bunch of batteries, and charge off a couple of RV batteries or small generator for a weekend event.  But we're talking several orders of magnitude more power with race cars.  I'm just not sure the technology is up to the logistics.... yet.

I will miss the sounds and smells when we get there...

 

MrChaos
MrChaos SuperDork
11/9/19 8:49 a.m.
Rodan said:
sleepyhead the buffalo said:

I was thinking: between this thread and Keith's EPA/CARB thread... that going to an EV race car is going to the thing to do before too long.

 

I just wonder how this is going to work, given current battery tech...  let's say you're running a typical race/HPDE weekend, say four 20 minute sessions followed by a 30 minute race each day for both days, Saturday and Sunday.  So that's 100 minutes of track time each day, assuming running full sessions, and needing the best power availability at the end of the day for the race.

Obviously, the best scenario is swappable battery packs, but now you need the equipment to do it in the pits, and batteries are heavy, so smaller modular packs would be best.  Either way, they still need to be charged in the pits... until tracks install charging infrastructure, how much generator do you need to keep up with the power use?  And you'll need to carry fuel for the generator.

I'm not really opposed to electric performance... I went through the transition from fuel to electric in RC aircraft over 10 years ago, and there are definite benefits.  But it was easy to carry a bunch of batteries, and charge off a couple of RV batteries or small generator for a weekend event.  But we're talking several orders of magnitude more power with race cars.  I'm just not sure the technology is up to the logistics.... yet.

I will miss the sounds and smells when we get there...

 

it will also be better for noise issues and tracks since they wont be as loud and no exhaust race cars which would mean tracks could likely stay open longer or open in more places.

wspohn
wspohn Dork
11/9/19 12:27 p.m.

Keith - interesting idea for sure, but it presents some substantial packaging challenges given that some of the EV cars use battery packs low down in the floors for lower centre of gravity.  The choice appears to be to to accept a higher centre of gravity with possible handling consequences or do a whole lot of work to get the bits mounted low down in the receiving car.

I see a few Miatas have had some sort of EV conversion - have you done any?

A family member recently bought an EV  and I have to admit that the instant torque is habit forming. If only the first generation Tesla Roadster had come down enough in price for me to consider it......sad

Keith Tanner
Keith Tanner MegaDork
11/9/19 2:41 p.m.

I’ve never had my hands on an EV Miata, but I’ve spoken to a pretty high number of owners. Usually while doing suspension design. Every single one is done like the Mustang, a motor stuck on the end of the trans. That’s a car that’s carrying around a vestigial transmission and an extra wasteful 90* turn in the power transmission that’s just not needed. 

The one I want to do would have a “transverse” motor in the rear subframe, basically a complete Tesla 3 RWD drivetrain. Then you can put batteries in the trans tunnel (low and central) and maybe some in the engine bay. You can get them nice and low and you’ve got an extra 140 lbs or so to “spend” on batteries. But that’s a lot harder than a big aluminum adapter plate to hook up a motor to the trans. 

I’ve been thinking about it for a couple of years. With my new Tesla seat time, I’m even more interested. But in reality I know I’ll never get the chance to build it, so I want someone else to do it for me :)

Pete Gossett
Pete Gossett MegaDork
11/9/19 5:34 p.m.

In reply to Keith Tanner :

Chargin’ Miata

Keith Tanner
Keith Tanner MegaDork
11/10/19 10:46 a.m.
Pete Gossett said:

In reply to Keith Tanner :

Chargin’ Miata

I may have to expand on your business plan slightly to make it viable :)

_
_ Dork
11/10/19 11:28 a.m.

I'm gonna have to request that FM do the first lightning powered Miata. Then sell me the kit. I'll buy as long as you keep the kit under 5k. 
please name the project car "Raiden" from the video game Mortal Wombat. 

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