Electric 914 Conversion - Fully Documented, Current state of 914EV Conversions Options

[mcbrems]

I’ve been away from the forum for a while. During this time I've done complete electric conversions on both of my 914s and have been driving them daily. I've also converted a bunch of VW Beetles, Buses, a Ghia, and several 356 replicas, but I'm only here to talk 914, and I owe it to this community to share back for all the help you've given me over the years.

When I started my first conversion in 2010, lithium batteries had just become accessible to the public. Telcom companies were using LiFePO₄ cells as UPS backup for cell towers, and that availability propelled EV conversions from hobbyist into practical daily driver territory.

My first build was a ground-up ’74 restoration using prismatic LiFePO₄ cells. Shortly after, salvaged Tesla Model S battery modules became widely available. They offer strong energy density for the cost and they simplify the design. Both of my 914 conversions use Tesla modules housed in custom battery boxes designed specifically for the chassis. There is now a healthy variety of new lithium batteries to choose from, so it's likely I will come up with new box design.

My first '74 conversion uses the HPEVS AC-50 motor and Curtis 1238-7601 controller, giving equivalent power and torque to the stock flat four engine, and using the stock 901 side shift transaxle. A lightweight flywheel and clutch is mounted on the motor shaft, and then married to the transaxle with an off-the-shelf adapter.

My second '75 conversion uses the NetGain HyPer9 HV permanent magnet AC motor with an AC-X144 controller. Output is about 20% more horsepower and 40% more torque than stock. The driving experience remains very 914 - smooth, quick and now sounding like a little UAP.

• The open fuel tank space is used to house the electric ceramic core heater, the DC/DC converter, the relay box, and the small 12V motorcycle battery.
• Three Tesla modules sit in a front trunk battery box ahead of the firewall.
• The engine bay uses a custom motor crossbeam that maintains factory drivetrain angle and mounting geometry, and provides support for dual battery box saddlebags.
• Seven Tesla modules provide the 175 VDC that the controller needs to operate at maximum peak performance.
• Dual chargers are mounted on the front firewall of the motor bay above the rear battery boxes.
• Charging port is located under a flip-down license plate holder on the front bumper.
• Cabling joining the front and rear battery boxes travel through the tunnel, while the signal harness bundle runs up the unused driver side rocker heater duct, and the 12V and high voltage bundle is separated into the passenger duct.
• All BMS data is transmitted via Bluetooth to a Samsung Galaxy tablet in the console.
• Total dry curb weight after conversion is 2413 lbs.

Range is typically 100–120 miles, which covers my daily use comfortably. Longer trips might require a stop for a sandwich and coffee.

The tech has evolved significantly since the early conversion threads here. Modern batteries and controllers simplify packaging significantly. The challenge now isn’t feasibility - it’s doing it cleanly.

I'm happy to answer technical questions for anyone considering it. I documented the process carefully because I wished that roadmap existed when I started.

Cheers,
Mark

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[fiacra]

Thank you! Nice looking car. I don't possess the skills to do a conversion myself, but I'm glad that there are people out there who have proven the concept is viable. I'm been hoping someday I'll be able to have my '75 1.8 converted. 100 mile range is plenty for me so maybe the time is now... Can you share with us the cost involved, how long the conversion took, and how reliable the vehicle is.

[Ninja]

That looks nicely done! (IMG:style_emoticons/default/first.gif)

The work is top notch; the car is gorgeous!

@TINKERGINEERING should take a look.

Just WOW! (IMG:style_emoticons/default/ninja.gif)

Has the top been "fixed"?

Sure looks that way!

I'm not really an electric guy but will be watching this post.

You seem to have your stuff together Sir! (IMG:style_emoticons/default/beerchug.gif)

[jim_hoyland]

Stunning ! (IMG:style_emoticons/default/smile.gif) You have a beautiful and functional conversion.

[emerygt350]

Is it still a 5 speed?

[914werke]

seeing the shifter I was going to ask the same.

[914werke]

Stunning ! (IMG:style_emoticons/default/smile.gif) You have a beautiful and functional conversion.

Well Im impressed its only a couple hundred lbs more than OG & indeed its a tidy install, ... but 100-125 mile range im not sure Id call functional. (IMG:style_emoticons/default/hide.gif)
Since you weighed it what is the bias post conversion, it appears to be front heavy now?

[Ninja]

I'd really appreciate some more pictures of the top if you can post.

Just love that!

extra 40% torque, details would be great!

Sounds everyday usable.

[Root_Werks]

That is a really clean conversion!

[Steve]

Is it still a 5 speed?

He has a similar post on Pelican. He says he still uses the higher gears 3-5.
http://forums.pelicanparts.com/porsche-914...documented.html
Very nice conversion. These have come along way. I know classic retrofit built one with a Tesla drivetrain. Very impressive, compared to early butchered cars with lead acid batteries.