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.