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Discussion Starter #1
For my next conversion (should I actually complete the first), I'd like to do a convertible. My favorite non-million-dollar convertible is a 289 Cobra, and I've been eyeballing the ERA kit for a while. They're the only company selling a 289 kit, and the 427 just doesn't interest me.

The ERA kit uses a Jaguar IRS with inboard brakes and it's weird:


They offer a version with outboard brakes, but the axle itself is the third link in the suspension, and I don't think that'd work with an electric motor and gearbox...

Ditching the diff and transmission gets rid of a lot of weight and complexity, and opens up prime battery real estate between the front seats...This matters a lot in a car this size...It just seems like a non-starter? Does Heidt or anyone offer options for these cars...? Track width is something like 61"...

Perhaps a compromise could be a Warp9-sized motor in the transmission tunnel with absurdly tall rear gears or a reduction box...?

 

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Someone on here did do a Tesla swap on a Cobra, I believe. They used a Kia Soul battery pack, and they raced it. Do a search; it should come up.
 

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This is the Cobra-bodied Tesla-powered race car:
Tesla Powered Race Car

Of course it's not really a Cobra, and nothing with a Jaguar suspension is a Cobra, either. That antique Jag setup is not worth working with in combination with an electric drive unit; it would make more sense to use any other kit with the desired body shape and a modern suspension (and likely better structure).
 

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Discussion Starter #4
That's the tricky bit—there's no other way into a 289 body shape without spending big money on a Superformance...

It looks like I'd either have to reengineer the rear suspension, and the first thing I say to anyone who heads down that path is...don't.
 

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That's the tricky bit—there's no other way into a 289 body shape without spending big money on a Superformance...

It looks like I'd either have to reengineer the rear suspension, and the first thing I say to anyone who heads down that path is...don't.
Factory Five Racing makes a Cobra kit car: Roadster - Factory Five Racing

Could that work for you? I believe they have an option that uses modern Mustang IRS, which may make the swap easier since you could replace the differential and axle shafts with the Tesla drive unit... if you can get it to fit.
 

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I'd give factory five the Tesla donor unit and let them figure out how to mount it...they stand to make a bunch of money if they had a LDU as a chassis option.
 

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I'd give factory five the Tesla donor unit and let them figure out how to mount it...they stand to make a bunch of money if they had a LDU as a chassis option.
I doubt that Factory Five would be interested. People have been EV-converting the 818 since it came out, and the factory has never adopted any of the designs. Mounting the drive unit isn't the challenge anyway - the battery is the challenge.
 

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That's the tricky bit—there's no other way into a 289 body shape without spending big money on a Superformance...
Really? I was going to list them, but soon realized that the list of companies building kits with a 289 Cobra (which means AC Ace) body style was too long to assemble and post.

Factory Five Racing makes a Cobra kit car: Roadster - Factory Five Racing

... I believe they have an option that uses modern Mustang IRS, which may make the swap easier since you could replace the differential and axle shafts with the Tesla drive unit... if you can get it to fit.
That's the obvious choice, due to Factory Five's popularity, but their Cobra style kit is one of the Mustang chassis designs - complete with beam axle - so that IRS option (also Mustang bits, but 2015+) is required, and might be expensive.

I think the key is to look for a kit which does not claim any authenticity or faithfulness to the original design, but has IRS (not the beam-axle Mustang bits that some use). Ironically Factory Five claims to be very authentic, even though no real Cobra ever had a beam axle. The real original AC Ace/Cobra suspension would certainly not be desirable, and the companies that push originality are expensive. The classic Jag IRS isn't good, but it was available and familiar for kit builders a generation ago, so some still use it.

The modern equivalent to the Jag IRS (well known, readily available, handles lots of power, excellent dynamics for the era) is the Corvette rear, C5 through C7 generations (most commonly C5, for salvage availability and cost). There have been C5/Tesla builds, including one in a Mercedes small van (Tesla powered Mercedes Vito). Logically there should be a C5-based Cobra kit, even with the Ford bias inherent in the Cobra fan world, but I don't know what it would be.

There are also kits replicating other models of the same period and style as the AC Ace, such as the big Healyes.
 

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My tuppence worth in this debate
I would get a kit and throw away the rear chassis
Then build a new rear section to take the motor and suspension I had acquired
And join the kit chassis and support the bodywork

I would be thinking about a Leaf unit

That would free up the entire engine bay and the transmission tunnel for batteries
Or you could possibly shrink the center tunnel and free up enough space for batteries in the sills
 

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I would get a kit and throw away the rear chassis
Then build a new rear section to take the motor and suspension I had acquired
That may be the most practical way to go, for someone with the fabrication skills.

I would be thinking about a Leaf unit
A Leaf drive unit would have the advantage of placing the motor within the wheelbase, instead of hanging behind the axle.

That would free up the entire engine bay and the transmission tunnel for batteries
I think a Tesla motor would usually imply a complete drive unit in the rear, which does have this packaging advantage, with any brand or model of drive unit. Of course, it is possible to separate even the Tesla motor from the drive unit.

Or you could possibly shrink the center tunnel and free up enough space for batteries in the sills
This is a Cobra body, not a Ford GT40 body. The transmission extends far enough rearward that there is a significant tunnel between the seats, which might be wide enough for useful battery modules; however, from door to door I'm pretty sure that it isn't wide enough for two seats and two sills wide enough for battery modules, even without any console. The desire is for the earlier style body as equipped with the 289, but even the later wide-body variants (with the 427) are only significantly at the fenders, not through the passenger compartment.

ERA Slabside interior for illustration:
http://www.erareplicas.com/cars/3002/interior.jpg

Looking at this, if the central tunnel isn't used (for a transmission, motor, or battery pack) it would certainly be nice to eliminate the bellhousing bulge and move the seats inboard a bit for a more comfortable seating position centred on the steering wheel and with good foot room. Of course, every "Cobra" kit is different.
 
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