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Discussion Starter #1
Hey everyone. I am a solar/mechanical engineer with a solar power system on the roof and decided to build an electric roadster. My guess is that some of you might find this interesting while many will find using an electric motor in a roadster blasphemous. Would love to hear your opinions either way.

We will be using two parallel NetGain HyPer 9 motors and 10 salvaged Tesla Model S battery packs. These motors develop 350 ft-lbs at the flywheel which will provide 0-60 in under 5.0 second and a top speed of ~125 mph. As most of you probably know, maximum torque from the electric motors occurs at 0 RPMs and remains flat beyond 4,000, so acceleration is brisk and near constant.

The car will have a cruising range of over 200 miles. While the battery packs will add ~550 lbs, losing the engine, radiator, exhaust system, fuel tank and fuel will save several hundred pounds. Net, the electric roadster will be about 300 lbs. heavier than the gas equivalent. The long cruising range results from using a subset of batteries designed for a 5,000 lb. Tesla.

Looking forward to talking with you all. gw
 

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My guess is that some of you might find this interesting while many will find using an electric motor in a roadster blasphemous.
Nonsense! I love nostalgic automotive (although I'm likely one of the younger guys on this forum @ 36) but ignoring new technology is stupid. At one point, a 4-barrel carb or an MSD distributor was the "new tech". As long as it doesn't detach me from the raw driving experience, I'm game and what's not to love about instant torque?!

I'm excited to follow the build .. post frequently!
 

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This sounds awesome. Your car, your way!

Can't wait to see what the wiring and control system looks like. Will this be front wheel drive? I know almost nothing about electric cars haha.
IMO the weight increase is easily "outweighed" (sorry!!) given the performance improvement. Any idea how much this thing will cost?

I'm almost done with mine (Coupe, regular 5.0 donor build), but I keep trying to figure out what the next one will be. Maybe something like this... I'm a mechanical engineer as well, so please pour on the technical details :D
 

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Electric Roadster

Here is a link to over 50 Videos documenting an Mk4 Electric Roadster build including trips to the drag strip.

Perhaps you have seen this. If not, the info. should be quite valuable. Go to his play list and select Electric Cobra Build.



YouTube Playlist

https://www.youtube.com/user/ev99saturn/playlists
 

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Discussion Starter #12
In fact I wrestled over the choice between the MKIV and 818 for some time.

If I do another build, and its likely since this is so much fun, I'd probably go with the 818.
 

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Discussion Starter #13
Not cheap. The electric motors, controllers, electrical components will be about $12K. The batteries will another $10K+. It can be done for much less if one goes with a single motor and less range. Using 1 Netgain motor and 100 miles of range would have cut these costs in half.
 

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I followed Jeff's build when he first started posting and really enjoyed it.
While I really like a loud Ford V8 in them, I think the electric is pretty cool (and FAST) too!

I do have a question, maybe someone can explain.
I've seen a couple of these conversions on various cars and it looks like they generally replace the gas engine with an electric motor. What I mean by this is the engine is up front, longitudinal, with a "transmission", driveshaft, and rear-end. But aren't the Tesla's mounted in-line with the rear axle and not transmission, driveshaft, Differential?
Is there an advantage of one vs the other?

Thanks & Good Luck!
 

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Not cheap. The electric motors, controllers, electrical components will be about $12K. The batteries will another $10K+. It can be done for much less if one goes with a single motor and less range. Using 1 Netgain motor and 100 miles of range would have cut these costs in half.
Get on Ebay......
used Tesla complete drive-train $6,500
salvaged battery pack $2,500
It has gotten incredibly affordable to make a Kick-ass conversion, now that oem's have produced so much salvageable components

Jeff
 

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‘My guess is that some of you might find this interesting while many will find using an electric motor in a roadster blasphemous.“

Absolutely not! Part of what makes this FFR community great is all of the innovation that is generated here. Mix that in with us loving these cars and that’s a win win. Can’t wait to hear more about your project. BUILD THREAD!
 

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Discussion Starter #17
Used Tesla Parts

Get on Ebay......
used Tesla complete drive-train $6,500
salvaged battery pack $2,500
It has gotten incredibly affordable to make a Kick-ass conversion, now that oem's have produced so much salvageable components

Jeff

Jeff, I've been on eBay and took another look after this email. Most of the 24 volt Tesla park modules cost over $1,000 and closer to $1,250. I am going to need 4 or 5 (96 or 120 Volts) times 2 for the two motors. So I will need 8 or 10 of the Tesla S battery modules. Am I missing something here?
 

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Buy a Nissan Leaf Pack or GM Volt pack for $2500. Just call salvage yards in our area. With the Leaf you get 25kw of modules.
Jeff






Jeff, I've been on eBay and took another look after this email. Most of the 24 volt Tesla park modules cost over $1,000 and closer to $1,250. I am going to need 4 or 5 (96 or 120 Volts) times 2 for the two motors. So I will need 8 or 10 of the Tesla S battery modules. Am I missing something here?
 

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Discussion Starter #19
Jeff, sorry I did not get a chance to talk with you more in Huntington Beach. I have a few questions:

i) What motor and batteries are you using?

ii) What is the rated torque at the flywheel?

iii) Do you have an estimate for 0-60?

iv) Do you actively cool your batteries?

v) How many laps can you do at Laguna Seca at speed before you overheat or run out of power?

vi) How long does it take you to recharge between sessions on the track?

vii) How do you recharge at the track?

viii) What events do you run?

ix) Will you be at Re-Fuel 2018 this year?

x) What is you email address so we can communicate without going through the forum?


Thanks and great seeing you at HB. gw
 
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