The 7-97 E-Volt: A Timeless Porsche Transformed for the Electric Future

Retrofitting the 964 for the Future

Kalmar Automotive has redefined what it means to be a modern coachbuilder. Operating out of Denmark and Estonia, Kalmar Automotive’s latest project, the 7-97 E-Volt, is a masterful vitalization of the Porsche 911 (964 generation), powered by cutting-edge electric technology.

Having previously worked for Porsche on iconic models such as the 918 Hypercar and the 991-911, Jan Kalmar brings unparalleled expertise to his company. A proud Dane, Jan strategically based Kalmar’s operations in Estonia, where their factory and workshop are situated within a FIA-grade race circuit—ideal for rigorous testing and fine-tuning.

Jan’s foray into EV conversions began unexpectedly. A customer’s request for an electrified Porsche initially caught the team unprepared. “We didn’t offer EVs at the time, only ultra-high-spec Flat-Six versions,” Jan admits. “But at Kalmar, we’re not ones to shy away from a challenge.” Embracing the project with their hallmark “Automotive Haute Couture” approach, the team meticulously crafted every detail of the build. Two years later, the result was the stunning 7-97 E-Volt—a car that balances sustainability, performance, and design in equal measure.

Crafting the Perfect (EV) 964

The foundation of the 7-97 E-Volt is the Fellten electric conversion system, a “plug-and-play” powertrain and interface rooted in Tesla’s proven Model S technology, to which Kalmar automotive brought some unique upgrades as a part of their ethos. At its heart is a reengineered Tesla Large Drive Unit, tuned to deliver an impressive 450 horsepower and 600Nm of torque. This is paired with a single-speed gearbox featuring a 9:1 reduction ratio and a Quaife ATB differential, ensuring optimal power delivery and traction.

The power system is driven by an Orion battery management system, which regulates the car’s 62kWh battery pack composed of 24 CALB 355 VDA modules. Each module, rated at 2.5kWh, is securely mounted to custom billet aluminum liquid cooling plates for exceptional thermal management. These modules are then housed in waterproof, custom-designed metal enclosures, perfectly fitted to the Porsche’s chassis.

Thermal Efficiency at Its Core

Advanced thermal management ensures the system operates at peak efficiency. Dual radiators keep temperatures in check during fast charging, while a heat exchanger recycles motor heat to maintain optimal battery temperatures in colder climates. This fine balance of cooling and heating is crucial for preserving performance across diverse driving conditions.

A Fellten bidirectional 6.6kW onboard charger replenishes the battery pack and powers a 2.5kW DC-DC converter, seamlessly supporting auxiliary systems such as lights and wipers. To achieve ideal weight distribution, the battery pack is split between the front and rear compartments. With a range of over 220 miles and CCS fast-charging capabilities, the 7-97 E-Volt delivers both practicality and excitement. “Remarkably,” Jan notes, “the E-Volt’s efficiency surpasses the Porsche Taycan, largely due to its lighter weight—even with the battery and motor, it’s leaner than a 964 Turbo!”

The Green Mean Machine

Kalmar Automotive’s work goes far beyond the drivetrain. The car’s exterior features plant-fiber composite panels, a CO2-positive material that absorbs carbon dioxide during its growth. “These panels, woven similarly to carbon fiber, provide a sustainable yet lightweight alternative,” Jan explains. “They’re challenging to work with but perfectly align with our commitment to sustainability.” The E-Volt is among the few cars worldwide to utilize this cutting-edge material.

Weight-saving measures extend to the use of thinner, Finnish-made glass, significantly reducing overall mass. Aerodynamic enhancements include the removal of the iconic 964 rain gutters and the integration of flush-mounted windows. These changes refine the car’s profile, reduce drag, and enhance high-speed stability, making it equally at home on the Autobahn or navigating tight Alpine roads.

A Bespoke Interior

The interior of the 7-97 E-Volt is another area where Kalmar’s craftsmanship truly shines. Every surface is handcrafted, primarily using locally sourced leather. The material’s luxurious aroma and texture evoke the timeless appeal of classic Porsches, while the use of sustainable materials reinforces the car’s eco-friendly ethos. The seats, sourced from a more modern 997 model, have been ergonomically modified for modern comfort without sacrificing their vintage charm.

The dashboard houses custom gauges mounted in the original 964 positions, displaying vital information such as battery state of charge, power output, range estimation, and efficiency metrics. These instruments complement a sleek touchscreen infotainment system that provides a modern interface while preserving the car’s classic aesthetic.

Additional refinements include a sustainably wrapped steering wheel with precision stitching, recycled plant-fiber inlays in the door panels, and enhanced soundproofing for a serene cabin experience. The advanced audio system, tailored to the car’s unique acoustics, further elevates the driving experience. Features such as semi-automatic air conditioning, USB-C charging ports, and ambient lighting underscore the car’s thoughtful blend of heritage and modernity.

Collaboration and Customization

At Kalmar Automotive, every 7-97 E-Volt is a one-off creation tailored to the customer’s specifications. “Each build is a journey,” Jan explains. “From selecting materials to defining every detail, our clients are deeply involved throughout the process.”

This philosophy extends to performance customization. The electronically tunable suspension offers adjustable settings for a range of driving conditions—whether you’re cruising through city streets or attacking corners on a racetrack. Customers can also personalize the car’s exterior, including paint colors like the deep, British racing green-inspired hue aptly nicknamed Seaweed Green.

The Driving Experience

Driving the 7-97 E-Volt is an unforgettable experience. The Tesla-sourced drivetrain delivers instantaneous torque, launching the car with exhilarating acceleration. The lightweight construction and optimized weight distribution enhance agility, making the car feel precise in corners and stable at high speeds.

Kalmar’s electronically adjustable suspension provides versatility, effortlessly transitioning between comfort for daily drives and stiffness for spirited track sessions. The upgraded braking system ensures confidence-inspiring stopping power, while the steering delivers sharp, responsive feedback. This perfect harmony of engineering ensures that the 7-97 E-Volt not only matches but often surpasses its combustion-powered predecessors.

The 7-97 E-Volt defines what classic cars can become in an era of sustainability. At a starting price of $450,000 (excluding taxes and the donor car), it represents a significant investment. However, for those who value craftsmanship, performance, and exclusivity, the 7-97 E-Volt is worth every penny.

Beyond the Build: Kalmar’s Team and Vision

Kalmar Automotive’s success is built on the passion and expertise of its international team. Bringing decades of experience in engineering, design, and craftsmanship, the team shares a collective vision to redefine what classic cars can become.

The company’s Estonia-based facility allows for meticulous in-house production, ensuring every detail meets the highest standards. “We’re not just building cars; we’re creating art,” Jan emphasizes. By combining advanced technology with a respect for heritage, Kalmar is setting a new standard for sustainable luxury vehicles.

Looking ahead, Jan and his team plan to explore even more powerful configurations and experiment with innovative materials, ensuring Kalmar Automotive remains at the forefront of the EV conversion movement.

The E-Volt doesn’t compete with its combustion-powered predecessors—it surpasses them.

SPECS

The Kalmar 7-97 E-Volt Porsche

Owner: Kalmar Automotive
Location: Designed in Denmark, built in Estonia
Base Vehicle: 1990 Porsche 964
Vehicle Name: 7-97 E-Volt
Build Time: Two years
Cost: $450,000+ (excluding taxes and donor car)

Drivetrain

Refurbished Tesla Model S Performance motor (450 hp, 600Nm torque)
Single-speed gearbox with 9:1 reduction ratio
Quaife ATB limited-slip differential
Regenerative braking integrated
Battery System
62kWh (24 CALB 355 VDA modules, 2.5kWh each)
Mounted to custom billet aluminum liquid cooling plates
Custom-designed waterproof metal enclosures for front and rear compartments with Integrated high-voltage wiring, connectors, and BMS modules
Dual radiators and heat exchanger for thermal management
Heat exchanger capable of recycling drive unit heat to maintain battery performance in cold conditions
Range: 220+ miles
Charging: CCS fast-charging, 6.6kW onboard bidirectional charger
2.5kW DC-DC converter for auxiliary systems

Chassis & Bodywork

CO2-positive plant-fiber panels
Aerodynamics: Flush-mounted windows, no rain gutters
Weight: Lighter than original ICE 964
Suspension, and Brakes
Suspension: Electronically adjustable adaptive suspension system
Brakes: High-performance braking system with regenerative braking integration

Wheels and Tires:

Lightweight alloy wheels designed for performance
High-grip, low-resistance tires

Interior

Modified Porsche 997 seats with sustainable leather
Custom gauges for battery metrics and performance data

Semi-automatic air conditioning, rain sensors, advanced soundproofing, USB-C charging ports, high-end custom audio system, custom high-fidelity sound system, tuned for cabin acoustics, integrated subwoofers for immersive audio

Discover more about Kalmar at:
www.kalmarautomotive.com

The Fellten System is available through
Legacy EV, www.legacyev.com