Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Thinking about converting a miata to electric

Yes. I found one that is nonfunct and wondering what I am looking at to convert it to electric. What’s your experience on this? Would I do better to stick a motorcycle engine and drive train under it?

Unless you get some crazy motorcycle engine, I don’t see it doing a very good job of powering that car. The Miata is light, but it still weighs a good deal more than a bike.

As for converting it to electric: Sure, go nuts. Just be aware that you are not going to save any money by doing it, because whatever money you save in gas, will be spent in the conversion.

That said, it sounds like a cool and fun project. Your biggest obstacle will be batteries. Because the patent for the batteries that are really good for cars is currently owned by GM/Texaco, you’re going to have to make compromises, and it’s going to cost you a lot of money.

You’ll be money ahead if you just sell the Miata and just buy an electric car. If it was easy and cheap to build a good electric car, you would see them everywhere.

And I don’t think it’s a Detroit/big oil conspiracy. The technology just has its limits.

There was a car made back in the 1970’s called the Citicar. The Citicar was an all electric vehicle. If you could locate one of these, you might be able to adapt the motor and batteries to the Miata. I think your converted Miata might be safer than the flimsy Citicar. However, the Miata is probably heavier, so the the converted Miata would be rather slow.

Swapping in a V8 from a Suzuki Hayabusa sport bike is apparently a quite fun swap for small cars and there’s at least one Miata-busa in the works:

That said, both projects proposed by the OP fall squarely into the “if you have to ask…” category. Both would only be reasonable for someone with lots of time, know-how and a very nice shop-- you’ll bankrupt yourself paying someone else to do the work on a zany project like this. If you have to ask such general questions on this board, I can pretty much guarantee you’re in over your head.

At the time I made the decision to either be a mechanic or go further on in school, electric cars were really in a “flux” stage (early 70’s) now I really wish I would have chosen to get involved in battery development, just look at how long it has taken (without my help:) Story this week on how GM is placing a 7 year lifespan on the battery for the Volt, I guess the lifespan could be worse.

The first consideration would be how much money (in buckets) do you have and how much are you willing to sink into a project like this. Even doing all of the work yourself it’s going to involve cash and headaches.

If it were mine I’d drop a supercharged Buick 3.8 in it. That would make it a functional, reliable car that gets great mileage to boot not to mention eyeball smearing fun.

Fifteen or twenty years ago or so, one department in the University where I am employed converted a Ford Escort to battery power. I don’t remember any of the details or how the car worked out. Most of the time the car was plugged into a charger outside the building. The vehicle disappeared about ten years ago, but apparently it did run.

Now that’s a Miata conversion I think even I would like!

I’m thinking that the Miata might not be the best choice for an electric conversion – at least not your first conversion. There’s not a lot of space for batteries and other hardware. You won’t have much control over the form factor of the parts you want to use. I’d be concerned about not being able to fit stuff in. It might be better to convert some lightweight vehicle with a lot of volume – maybe the smallest pickup truck you can find.

Home Power Magazine, one or two issues back, had an excellent article detailing how someone in Washington state converted a Toyota Echo to 100% electric power. He was able to achieve his goal of a 60 mile range with a 60 mph top speed using common golf-cart lead-acid batteries. He purchased the electric motor, controller and transmission adapter as a kit. He still had to shift the car, which I found surprising…

Getting that 60 mile range was difficult and he had to discharge the batteries deeper than he had planned, which he realizes will greatly shorten their life…Also, the cars weight was right at its rated capacity…Handling and braking were marginal…

I was actually thinking of that exact motor when I said “crazy motorcycle engine” :wink:

That wouldn’t save him a whole lot on fuel (which I assume is why he’s doing this), and if he’s doing it for power, there are a lot cheaper ways to soup up a Miata.

Part of the battery technology problem is due to patents. The guy that invented the (very good) batteries used in prototype vehicles like the electric RAV-4 (some of which are still on the road on their original batteries) sold the patent to GM, assuming they’d use it to develop electric cars. GM turned around and sold it to Texaco, which is now sitting on it to try and retard electric car development. Cute, huh?

" GM turned around and sold it to Texaco, which is now sitting on it to try and retard electric car development. Cute, huh?"

Good story - any proof? These allegations surface all the time. I find it hard to believe that the WORLD’s desire for electric vehicles is hobbled by some patent.

I’m sort of with you on this, texases…

Chevron did, in fact, control some patents on NiMH battery technology. However, the “guy” who created the company that developed that technology, Stan Ovshinsky, has publicly stated that he does not believe Chevron is holding back the batteries. Instead, he believes the problem is that producing the larger batteries for EVs (as opposed to the smaller ones they continue to make for hybrids) requires an infusion of cash into the business, and the joint venture that Chevron controls does not have the cash needed to start production. That’s why they’re saying they’ll take large OEM orders… (ie, you order enough of these to make the construction of the necessary factory viable, we’ll make them for you)

Most of these patents expire by 2014.

But today, the company in question is in fact a joint venture owned by Bosch and Samsung - Chevron is no longer in control, and it was highly questionable they were ever trying to “retard electric car development” - if they could have made a buck on it, believe me, they would have…

If you’re a talented sparky, you could certainly do this, but you’ll probably spend a good amount of money.

A local company here does professional conversions of the Chevrolet Equinox to an EV. Based on their stated charge times, it looks like they are probably using around 22 kWh per charge, which makes me think they’re likely needing around a 35-40 kWh battery to avoid deep discharge to maximize life.

And given typical costs of $350+ per kWh, that’s near $13k in battery costs alone… they list the cost as $25k for a conversion (after tax credits).

So could you? Sure… but I’d bet you end up forking out $10k+ for batteries, then you’ll have to put in electric motors, etc… You’re probably better off contracting it out to a conversion company… or wait and buy a purpose built EV - the Nissan Leaf and Chevy Volt both aren’t going to cost that much more than the conversion at our local place alone (and you have to buy the Equinox first, which means you’re paying for the powertrain that they get to resell).

Thanks. I enjoyed reading what you had to say. Is there a more reasonable thing to do like look at the three wheeler hybrids that I heard about in Consumer Reports? Did you see the movie ‘The Worlds Fastest Indian’? What did you think?

Detroit Oil conspiracy? I agree. They are not that coordinated. There are better real life conspiracies around. When the city re-paved some of the streets behind the DPS they actually moved the curbs closer into the street by two feet on each side. They said it was to give the trees more room to grow. I am certain it is actually to make the streets back alley size and harder to get to the DPS through.

Sounds like the equivalent to an AirCoup. I’ll look up Citicar. Thanks

How good is the Volt likely to be? We want to buy our last car before retirement but i am trying to get my beloved to hold out as long as possible so we actually consider the alternative.