Would You Electrify Your Compact Sports Car?

Bolting a motor to an existing transmission is the lazy and crappy way to do it. Great for getting media attention for your "we're totally taking this EV thing seriously" SEMA cars such as that truck, but not much else. Maximum weight, minimum space efficiency, maximum power loss, minimum strength. Ford showed an electric Mustang at that same SEMA and it was a "motor on a trans" conversion that has never been seen again, it only existed to let the manufacturers know that Webasto had some components that could be used. Meanwhile, the Mach-E is real.

GM does have crate kits announced, basically a disassembled Bolt. Since the battery pack is a monolithic unit designed as a skateboard for the Bolt, you don't really have much in the way of packaging options. That's their press release variant, the real proper offering is the next version which will use their modular batteries.

Better option is the EV West piece that is packaged like a SBC with trans. Bolt it on to SBC motor mounts and add a driveshaft to the rear diff. It's not cheap - it uses a junkyard Tesla motor coupled to a custom gearbox, and custom gearboxes are expensive - but it's a much better solution. Never one that will be used in a production car so you'll never see the prices that come from mass production. It's retrofit only and possibly an evolutionary dead end. 

There are a few other options on the market like the Swindon power unit. Roughly 160 hp, a complete engine and gearbox packaged like a FWD drivetrain or a mid-engined drivetrain. That's your AW11 solution. They cost money but such is the nature of cutting edge aftermarket pieces. They have a 100 hp version that would make my classic Mini much, much less of a pain in the ass. 

WRT rising powerbands and fun - I had some extended exposure to a centrifugal supercharged NC Miata on street and track. Pretty much the definition of rpm = hp and more extreme than you get with a naturally aspirated car. It was really kinda fun to cane on track until you hit traffic or needed a bit of flexibility. Performance dropped off so fast if you were not revving the nuts off the engine that it got a little frustrating. I know some people like the feel, but compared to my usual LS3 powered Miata it felt too finicky and had too small a range of available performance. After driving a car that was always ready to party, the rising powerband car was only able to deliver occasionally. I didn't get joy out of constantly shifting to stay in that area of peak performance, especially when surrounded by cars of varying speed.

On the street, it was weird because you had to back off the throttle to maintain a constant acceleration even at normal traffic speeds. You could get used to that but it was marketly noticeable. 

The kit was being evaluated for addition to our catalog, and all the decision makers involved gave it the thumbs down due to the performance characteristics. Rising powerband setups like that sound great in forums when you're bragging about purity and engagement etc, but when you're in a pack of cars and you keep losing pace because you're constantly messing about to be in the One True Gear it's less fun. Turns out that having a car that's always got your back is better.

I don't have the dyno charts here, but I suspect the torque curve on that thing was climbing and not flat. The LS curve is much closer to an EV. People comment on my videos that the engine sounds "lazy", but that's because the rate of acceleration isn't really changing.

And because I came across it, here are the efficiency and power/torque ratings for that 160 hp Swindon power unit. These guys are actively shipping the 107 hp variant.

Interesting that their efficiency sweet spot is largest at the highest RPM available.  Looks quite a bit different than your typical BSFC chart for an ICE.

Keith Tanner said:

Keith Tanner said:

If only I had a Miata on my lift right now. Wait a second...

Eyeballing, I think you could fit three of them in a Miata tunnel. I'll back that up with a tape measure soon.

As for software, there are third party controllers that can run a Tesla Model S power unit. Not the 3 yet to the best of my knowledge. Pity, because the 3 motors are very clearly 2-3 generations further along in evolution although they're not as monstrously strong.

Two in a tunnel without any modifications. They'll run roughly from the rear bulkhead to the front shock towers. You could fit a third if you were willing to widen the top of the tunnel by a couple of inches.

Or, fun fact, the exhaust on my V8 NA hangs a total of 3" below the floorpan. I think you could plausibly "skateboard" the car without a major problem.

I think with my Fiat, if I cut the trans tunnel I could probably get two of the packs in the same way,  as I rarely carry passengers, I could alter the passenger floor to lay one of them down the "normal" way beneath the car and still keep it protected, possibly two. I would just need numbers for the size of each pack.  All it would mean is a higher floor on the passenger side and possibly a fixed position seat.

Keith Tanner said:

I know some people like the feel, but compared to my usual LS3 powered Miata it felt too finicky and had too small a range of available performance.

I haven't driven one, but looking at dyno charts your LS3/525 looks like it would be what I'd describe as flat-to-slightly-rising torque curve.  It starts out high and stays high. :)

Yeah, I realized after writing that post that the centrifugal probably had a rising torque curve to go with the boost level. 

mad_machine (Forum Supporter) said:

Keith Tanner said:

Keith Tanner said:

If only I had a Miata on my lift right now. Wait a second...

Eyeballing, I think you could fit three of them in a Miata tunnel. I'll back that up with a tape measure soon.

As for software, there are third party controllers that can run a Tesla Model S power unit. Not the 3 yet to the best of my knowledge. Pity, because the 3 motors are very clearly 2-3 generations further along in evolution although they're not as monstrously strong.

Two in a tunnel without any modifications. They'll run roughly from the rear bulkhead to the front shock towers. You could fit a third if you were willing to widen the top of the tunnel by a couple of inches.

Or, fun fact, the exhaust on my V8 NA hangs a total of 3" below the floorpan. I think you could plausibly "skateboard" the car without a major problem.

I think with my Fiat, if I cut the trans tunnel I could probably get two of the packs in the same way,  as I rarely carry passengers, I could alter the passenger floor to lay one of them down the "normal" way beneath the car and still keep it protected, possibly two. I would just need numbers for the size of each pack.  All it would mean is a higher floor on the passenger side and possibly a fixed position seat.

Dimensions were in the same post as the picture. They're long, that's going to be the biggest hurdle for compact cars.

I mentioned doing a ghettocet leaf. This is a rather poorly made video, but if you skip to the 7:30 point, there's a stripped down Leaf giving a Mustang grief in a drag race:

https://www.youtube.com/watch?v=JdpmOwY5gVM&feature=emb_logo

I mention this because it's a way for someone to play with a quasi-fast EV without spending a bunch of money or taking a risk messing with high voltages. You could even pull the body off something classic and set it on top, although you'd lose some of the weight savings you gained by removing the Leaf body - and the Leaf has a long wheelbase that would have to be contended with.

In reply to Keith Tanner :

Understood. "Lazy and crappy" is my middle name!!

Seriously... I most certainly know the difference, and respect every single detail of "doing it the right way". However, that exceeds both my talent and my budget. 
 

My goal would be enjoyment. And I would deeply enjoy a classic vehicle converted to electric through bolt-on methods that I was capable of accomplishing well. 
 

Im glad there are people better than me in the world (like you), and I will continue to encourage and appreciate their efforts. 

I think the key to converting a live axle classic would be to come up with an axle that has the motor attached to it. I've tried to contact Eaton about it as they're showing something that might be suitable in one of their press releases, but I think they only talk to OEMs. 

My feeling is that we're in a time of transition for conversions. The old "forklift motor, stock trans and a bunch of lead acid batteries" technique has been made obsolete but the integrated setups aren't quite ready. Any conversion done now may not age well. You could see that at SEMA in 2019, there were fresh builds that were obviously outdated right from the start sitting beside more modern builds.

Still, find a way to attach a driveshaft to a Leaf gearbox and run it to the back wheels. Could be possible and would eliminate the stock trans nicely. Not sure what the rear end ratio of the diff would do to you, though. Might make for a low top speed :)

The GM future batteries interest me a lot too; they're apparently going for small modular packs that can have their guts removed at later dates instead of full cell-to-pack (like Tesla is wanting to do now) and plan on using Bluetooth as apart of the BMS instead of just physical connections. GM's really looking towards the aftermarket and i'm super interested since the Bolt/Volt batteries became the go-to.

In reply to wheelsmithy (Joe-with-an-L) (Forum Supporter) :

Right? Worse is he's actually funny and I know why he has to do it- it's the only way to make Youtube profitable. But I wanna see his work, not just him clowning all the time.

codrus (Forum Supporter) said:

GIRTHQUAKE said:

Oh! So you're asking for whole system efficiency? Like, how much power in --> X amount of power out kind of deal?

I can say- only as a hobbyist- that all copper busbars I've ripped out of packs have been extremely short. Hell come to think of it, each pack i've ripped apart used the batteries themselves to take up as much space as possible from it's destination (inverter and motor) to genesis (Charge port). That also aligns with the Tesla inverter placement and the Leaf's- their inverters are RIGHT next to the motors, and in both cases actually share coolant circuts to keep direct connections short. Maybe that's part of how their efficiency is so great?

That's just common sense packaging because copper is expensive and heavy.  Sure you get slightly less resistance by keeping the runs short, but 1 vs 2 feet of copper is a trivial amount.

Comparing "whole system" efficiencies you need to include the power plant.  If that power plant is burning hydrocarbons for fuel, then what you're asking is if the improved efficiency of a large scale, stationary plant is enough to outweigh the losses involved in generating electricity, transferring it over the power grid, charging a battery, and running an electric motor using that battery.  The answer is probably a little bit, but it's missing the point.

The real point to EVs (at least from an emissions perspective) isn't that it's a marginally more efficient way to burn hydrocarbons, it's that making the cars electric means you can run them off any kind of power source, not just hydrocarbons.  This is how you run a car off a hydroelectric dam, a solar power plant, or a nuclear reactor.

So not to be mean... but what are you looking for then? Total efficiency? Cost calculations? Estimated carbon impact? We have studies on most of those- even the last one! Volvo/Polestar did a deep carbon dive into the XC90 (since it comes in Gas, Diesel, Gas Hybrid, and EV versions) for carbon offset and even counted the type of electrical energy used while engineering and drafting the thing. I can post it when I get home tonight.

GIRTHQUAKE said:

So not to be mean... but what are you looking for then? Total efficiency? Cost calculations? Estimated carbon impact? We have studies on most of those- even the last one! Volvo/Polestar did a deep carbon dive into the XC90 (since it comes in Gas, Diesel, Gas Hybrid, and EV versions) for carbon offset and even counted the type of electrical energy used while engineering and drafting the thing. I can post it when I get home tonight.

Personally?  In the context of the original topic (sports cars) I'm looking for "fun to drive".  I enjoy gas engines more than I do EVs, so I'm looking for one of those. :)

Somehow the discussion wandered off onto efficiency and emissions, and seemed to have fallen into the "EVs just move the emissions to the power plant" fallacy.  I'm addressing why they do more than that, and thus why it's a fallacy.

As for studies there are lots of them and they almost always seem to support the position of the organization who did the study so I'm doubtful of most of them.  We don't really know which technology is better, the answer depends heavily on the assumptions that go into the models.  EVs are more flexible though, it's much easier to adapt them to different power sources than it is gasoline engines (at least until we come up with a good way to make gasoline out of CO2 and water)

No

Not for me. Pass.

Sorry I didn't get back to this for over a damned week.

codrus (Forum Supporter) said:

GIRTHQUAKE said:

So not to be mean... but what are you looking for then? Total efficiency? Cost calculations? Estimated carbon impact? We have studies on most of those- even the last one! Volvo/Polestar did a deep carbon dive into the XC90 (since it comes in Gas, Diesel, Gas Hybrid, and EV versions) for carbon offset and even counted the type of electrical energy used while engineering and drafting the thing. I can post it when I get home tonight.

Somehow the discussion wandered off onto efficiency and emissions, and seemed to have fallen into the "EVs just move the emissions to the power plant" fallacy.  I'm addressing why they do more than that, and thus why it's a fallacy.

As for studies there are lots of them and they almost always seem to support the position of the organization who did the study so I'm doubtful of most of them.  We don't really know which technology is better, the answer depends heavily on the assumptions that go into the models.  EVs are more flexible though, it's much easier to adapt them to different power sources than it is gasoline engines (at least until we come up with a good way to make gasoline out of CO2 and water)

The Polestar Life Cycle Assessment is an excellent place to start, then; page 4 has the portiioin you're looking for, stating:

The two main differences in the carbon footprint between the Polestar 2 and the ICE appear in the materials production (including the Li-ion battery modules) and the use phase. The carbon footprint from materials production (including the Li-ion battery modules) of the ICE is roughly 40% less than for Polestar 2. Looking at the category “Materials production” the five main contributors for the XC40 ICE are aluminum 34%, steel and iron 34%, electronics 13%, polymers 11% and fluids and undefined 4% (see Figure 10 for more details). For Polestar 2 the main contributors to the carbon footprint of the material production (including Li-ion battery modules) are aluminum 29%, Li-ion battery modules 29%, steel and iron 17%, electronics 10% and polymers 7% (see Figure 10 for more details). It should be noted that the carbon footprint was performed to represent a globally sourced version of the car models. Other methodological choices that have a large impact on the result are choice of allocation method regarding scrap, and choice of datasets for steel and alumin-ium production.

It's a pretty good, in-depth read that details even the primary energy source of the plant that is building the vehicles (In their case, Chinese coal-fired plants) and gives a break-even line graph on page 5 in thousands of kilometers. For their report, the break-even to save carbon from the atmo you'd have to drive your EV over 40,000KM powered sorely via renewables; decently easy in America thanks to things like Arcadia power and the proliferation of home systems, but proclaims that casting engine blocks is still more intensive than constructing battery banks. I wish Tesla would do one too, but I seriously doubt they ever would.

As for making gasoline out of atmospheric componenets, I wouldn't hold breath. So-called "BluGas" is being worked on by the likes of Porsche, Konisegg and such and has been for the last 10 years; they keep running headfirst into the same problem, that E85 trounces it all because nature is pretty good at energy conservation.

Personally?  In the context of the original topic (sports cars) I'm looking for "fun to drive".  I enjoy gas engines more than I do EVs, so I'm looking for one of those. :)

 Build an eBike I suppose? I've only been in one Tesla but I can totally see how someone would tire of something. Myself, I'm starting small with little 2-wheel and kart like projects, though that hasn't stopped me from crawling through junkyards in search of great forklift AC motors that can be rodded with hacked Priuss inverters and the like.

Volvo makes very similar vehicles in both ICE and EV modes, so they're in the best position to really evaluate the total energy cost taking supply chains into account. Tesla has never made a car with an ICE so they're not really able to make a good apples to apples comparison.

Sure, I could see myself doing something like this to my GTI some day. The neat thing about the base Golf platform is that there's plenty of space to work and it's designed to accept all wheel drive, so there are a variety of knuckle/hub and subframe assemblies to choose from to get power to all four wheels.

MrFancypants said:

Sure, I could see myself doing something like this to my GTI some day. The neat thing about the base Golf platform is that there's plenty of space to work and it's designed to accept all wheel drive, so there are a variety of knuckle/hub and subframe assemblies to choose from to get power to all four wheels.

Seems like it would be a lot easier and probably cheaper to just buy an e-Golf and add GTI suspension/etc bits to it. :)

codrus (Forum Supporter) said:

MrFancypants said:

Sure, I could see myself doing something like this to my GTI some day. The neat thing about the base Golf platform is that there's plenty of space to work and it's designed to accept all wheel drive, so there are a variety of knuckle/hub and subframe assemblies to choose from to get power to all four wheels.

Seems like it would be a lot easier and probably cheaper to just buy an e-Golf and add GTI suspension/etc bits to it. :)

 

The e-Golf is slow and has poor battery range, so it would have to be stripped to nearly the same extent to speed it up. With the way VW is going I wouldn't be surprised if they were to release an electric hot hatch, but what they have now isn't there yet.