Gettin Torqued: A Comprehensive Guide to Aftermarket EV Motor Systems

Electric vehicles (EVs) have made their mark on the automotive world—not just as eco-friendly alternatives to internal combustion engines (ICEs), but as platforms for groundbreaking performance, efficiency, and customization. For automotive mechanics and enthusiasts exploring EV conversions, understanding the motor system is the first step in creating a functional and powerful build.

In this guide, we’ll break down EV motor systems, compare them to ICE engines, explore motor types and installations, and review some of the most popular aftermarket motors.

What should be included in a “Motor System”?

An EV motor system is more than just the motor—it’s a fully integrated system of components working together to power your vehicle. Unlike the well-established terminology in the internal combustion engine (ICE) world—where terms like “short block,” “long block,” and “turn-key” have standardized meanings—the aftermarket EV space lacks such consistency. As a result, what’s included in a motor kit can vary significantly from one provider to another.

In this article, we’ll take a closer look at some common motor kits available on the market, breaking down what they include (and what they don’t), so you can make informed decisions as you begin your EV journey.

For now - lets take a look at all the main components you will need to get that motor spinning.

Motor: Converts electrical energy into mechanical motion via electromagnetism. You can think of this as the “block” of the gas motor where the mechanical action takes place. In subsequent articles we will dive deeper into motor construction and technologies. 

Inverter: Transforms DC power from the battery into AC power for the motor. You can think of this as the “top-end” of a gas motor but instead of controlling timing, fuel, and air delivery - we are manipulating current, voltage, and frequency. 

Vehicle Control Unit (VCU): Manages motor operation, akin to an ECU in ICE vehicles. It takes monitors operator and vehicle side inputs (throttle positions, battery health, vehicle speed), and then according to the tune and program commands the inverter and other EV components accordingly - most often via a CAN network. 

Cooling System: Prevents overheating of the motor and inverter during operation. Modern EVs require a lot of electrical current (up to 1200 Amps in some cases!) to keep vehicles scooting along and even though motors are 90% - efficient heat will still need to be managed.
Components include radiators, coolant pumps, hoses, and fittings.

High-Voltage Cables: Carry power between the battery, inverter, and motor; typically orange for safety. These cables are BIG as they need to carry a lot of current for long periods of time. 

LV Wire Harness: Connects sensors, switches, and controllers to ensure seamless communication between components. 

Sensors and Inputs: These inputs are often the same as what you find on a gas engine - typically measuring analog values with a 0-5V signal that is transmitted back to the VCU. 

Throttle Sensor: Communicates accelerator position to the system.
Drive Mode Selector: Controls forward, reverse, and neutral modes.
Brake Pressure Transducer: Engages regenerative braking.

Fuses and Fuse Holders:

• Protect the system from electrical faults.The main motor fuses are much larger than your standard motor fuses - often rated to 800+ Volts and 500+ Amps

Contactors:

• These are essentially relays however designed for high-voltage and high-current situations such as in an EV. Most EV motor systems will have at least two large contactors -

Focus on Permanent Magnet AC Motors

Among the various motor technologies available, permanent magnet AC (PMAC) motors are the gold standard for EV builds. Here’s why they are favored:

How They Work:

PMAC motors use magnets embedded in or mounted on the rotor. When alternating current flows through the stator windings, it generates a rotating magnetic field. This field interacts with the rotor’s magnets, causing it to spin and produce torque. The result is smooth and efficient power delivery, making PMAC motors the most common choice for modern EVs. 

Voltage Levels and Their Impact

The voltage level of your EV system is a key factor in determining the motor options available and the overall performance of your build. Each voltage range has its strengths and limitations, catering to different use cases. Here’s a detailed breakdown:

100V Systems

Ideal For:

• Compact, budget-friendly builds with modest performance needs.

Examples:

• Hyper9 Integrated System

Advantages:

• Simpler system design, making it accessible for beginners.
• Reduced component costs compared to higher-voltage systems.

Limitations:

• Lower power output and efficiency, limiting high-performance potential.
• Not compatible with DC fast charging, resulting in longer charging times.

Recommendation:

• A great starting point for newcomers to EV conversions or for builds prioritizing simplicity and cost-effectiveness.

400V Systems

Ideal For:

• Standard EV builds that balance performance, cost, and complexity.

 Examples:

• Nissan Leaf (EM57), Tesla Model 3 Drive Units, Maverick 25 Motor

Advantages:

• Widely supported in the aftermarket, with a broad range of compatible components.
• Offers excellent performance capabilities for most applications.

Limitations:

• Higher cost compared to 100V systems.
• While powerful, not as efficient or robust as 800V systems for extreme conditions.

Recommendation:

The most versatile choice for builders with experience in EV conversions. It offers the best balance between performance and accessibility for most projects.

800V Systems

Ideal For:

• High-performance or long-range builds, as well as heavy-duty applications.

Examples:

• Select motors from Cascadia Motion and Danfoss.

Advantages:

• Higher efficiency, especially at sustained high power levels.
• Faster charging capabilities, supporting DC fast charging at high rates.
• Increased power output and smaller wiring requirements, reducing weight and complexity.

Limitations:

• Higher cost for components and overall system design.
• Limited aftermarket support and component availability.
• Requires advanced design expertise and safety considerations.

Recommendation:

• Best suited for experienced builders working on demanding applications such as racing or heavy-duty vehicles.

Example Motor Systems in the EV Aftermarket

The EV aftermarket provides a diverse array of motors designed to cater to different budgets, performance goals, and system requirements. Below, we’ll explore three standout options across voltage ranges and levels of integration, highlighting their features and required additional components.

Hyper9 Integrated System

The HyPer 9 System™ is a versatile and beginner-friendly solution, making it a top choice for lightweight vehicles or newcomers to EV conversions. Designed around a Synchronous Reluctance Internal Permanent Magnet (SRIPM) motor, this system delivers exceptional torque and efficiency. Its compact size and integrated inverter simplify installation, and it offers one of the highest power-to-weight ratios in its class.

Key Specifications:

• Voltage: 100V
• Torque: 173 ft-lb
• Ideal for: Light to mid-weight daily drivers (can be scaled for heavy-weight or racing vehicles).

What’s Included:

• HyPer 9™ Brushless Motor
• HyPer-Drive X1™ Controller/Inverter
• SmartView Programming Software
• Low Voltage Wire Harness Kit
• Main Contactor

What You’ll Need to Add:

• Fuses
• High-voltage cables and connectors
• Throttle
• Coolant system

The Hyper9 is well-suited for builders seeking a straightforward and cost-effective option for reliable performance.

Cascadia Motion iM-225-DZ-S

The iM-225-DZ-S integrate Module from Cascadia Motion is a powerhouse packed with the CM200 inverter and HVH250 motor core, delivering up to 368 ft-lb of torque in a compact and modular package. With a maximum voltage of 840VDC, it’s an excellent fit for a variety of medium- to high-performance EV conversions.

Key Specifications:

• Voltage: 400–800VDC (supports 840V max
• Torque: 368 ft-lb
• Ideal for: Medium to high-performance builds requiring modularity.

What’s Included:

• Motor
• Inverter
• Water Pump

What You’ll Need to Add:

• Vehicle Control Unit (VCU)
• Fuses
• Contactors
• High-voltage cables and connectors
• Throttle
• Coolant system components

The iM-225-DZ strikes a balance between performance and adaptability, making it a favorite for builders seeking versatility in high-voltage systems.

ReVolt Systems 450kW Crate Motor Kit

For those seeking maximum power and a turnkey solution, the ReVolt Systems 450kW Crate Motor Kit delivers an impressive 450kW+ of power in a 400V package. Designed for simplicity, the kit includes nearly everything needed to get a project running. This high-performance system is ideal for builders looking to maximize speed and torque in their EV builds.

Key Specifications:

• Voltage: 400V
• Power: 450kW
• Ideal for: High-performance and racing applications.

What’s Included:

• Motor
• Inverter
• Gear Reduction Box
• Throttle Pedal
• 1350 Slip Yoke
• Wiring Harness
• T2C Controller

What You’ll Need to Add:

• Contactors and fuses (ReVolt offers a plug-and-play contactor box).
• Coolant system.
  
  

The ReVolt Systems kit is a top-tier option for builders who want maximum performance and minimal guesswork, though it comes with a higher price tag to match its capabilities.

Each of these systems offers unique advantages, from beginner-friendly simplicity to cutting-edge power. Choosing the right motor system depends on your build’s goals, budget, and technical requirements. Whether you’re working on a daily driver, a high-voltage beast, or a racing machine, the EV aftermarket has you covered.

Conclusion

Electric motor systems are transforming the automotive world, offering mechanics and enthusiasts an opportunity to build cleaner, faster, and more reliable vehicles. While the learning curve might seem steep, understanding motor systems and their components will demystify the process. 

Stay tuned to Amped Up for more deep dives into EV tech including motors, and don’t hesitate to connect with Legacy EV for expert advice on your next build! 

Interested in learning from our team of educators, car-builders, engineers, and technicians? We offer a Fundamentals Bootcamp at our HQ in Gilbert, AZ.