Hey there, BMW E30 enthusiasts! Are you looking to enhance your driving experience with improved steering? If so, an electric power steering (EPS) conversion might be just what you need. This comprehensive guide will walk you through everything you need to know about converting your classic E30 to electric power steering. We'll cover the benefits, necessary components, step-by-step installation, and troubleshooting tips to ensure a smooth and successful upgrade. Buckle up, and let's dive in!

Why Convert to Electric Power Steering?

Electric Power Steering (EPS) offers a multitude of advantages over the traditional hydraulic power steering systems found in the BMW E30. EPS systems are more efficient, reliable, and customizable, making them a popular upgrade for classic car enthusiasts. Let's explore the key benefits in detail.

Enhanced Efficiency

One of the primary advantages of converting to electric power steering is its improved efficiency. Unlike hydraulic systems, which constantly draw power from the engine via a belt-driven pump, EPS systems only consume power when steering assistance is needed. This on-demand functionality reduces the load on the engine, leading to improved fuel economy and reduced emissions. For those who use their E30 as a daily driver or are conscious about environmental impact, this efficiency boost can be a significant benefit.

Moreover, the reduced load on the engine can translate to a slight increase in overall performance. While the gains might not be dramatic, every little bit helps, especially in a car like the E30, where performance and driving feel are paramount. The EPS system's efficiency also means less heat generation, which can contribute to the longevity of other engine components.

Improved Reliability

EPS systems are generally more reliable than their hydraulic counterparts. Hydraulic systems are prone to leaks, pump failures, and hose degradation, which can lead to costly repairs and maintenance. Electric power steering systems, on the other hand, eliminate many of these potential failure points. With fewer moving parts and no need for hydraulic fluid, the risk of leaks and mechanical failures is significantly reduced. This increased reliability translates to less downtime and lower maintenance costs over the lifespan of the vehicle.

Furthermore, EPS units are typically sealed and protected from the elements, reducing the risk of corrosion and damage. This robust design ensures that the EPS system can withstand the rigors of daily driving and provide consistent performance in various conditions. For E30 owners who value reliability and want to minimize maintenance, an EPS conversion is a worthwhile investment.

Customizable Steering Feel

Another significant advantage of electric power steering is the ability to customize the steering feel. Many EPS systems offer adjustable settings that allow you to fine-tune the level of assistance based on your preferences. Whether you prefer a light and responsive feel for city driving or a more weighted and precise feel for spirited driving, an EPS system can be tailored to your needs. This level of customization is simply not possible with traditional hydraulic systems.

Some EPS kits come with pre-programmed profiles that cater to different driving styles, while others allow for even more granular adjustments via a control module. This flexibility ensures that you can optimize the steering feel to match your driving habits and preferences, enhancing your overall driving experience. For E30 enthusiasts who are particular about how their car feels on the road, the ability to customize the steering feel is a major selling point.

Space Saving

Electric power steering systems are more compact than hydraulic systems, which can be particularly beneficial in the relatively tight engine bay of the BMW E30. The elimination of the hydraulic pump, hoses, and fluid reservoir frees up valuable space, making it easier to work on other components and potentially improving airflow. This space-saving aspect can be especially appealing for those who have modified their E30 or plan to do so in the future.

The compact design of EPS units also simplifies the installation process, as they can often be mounted directly to the steering column without requiring extensive modifications to the vehicle. This streamlined installation can save time and effort, making the EPS conversion more accessible to DIY enthusiasts.

Essential Components for the Conversion

Before you embark on your electric power steering conversion, it's crucial to gather all the necessary components. Here's a detailed list of what you'll need:

Electric Power Steering Unit

The heart of the conversion is the EPS unit itself. Several options are available, but a popular choice for the E30 is the EPS unit from a Toyota MR2 (SW20) or a Saturn Vue. These units are compact, reliable, and readily available. Ensure the unit you choose is in good working condition and comes with all necessary connectors and wiring.

When selecting an EPS unit, consider factors such as its size, power output, and compatibility with your E30. Some units may require additional modifications to fit properly, so it's essential to do your research and choose a unit that is known to work well with the E30. Additionally, check the unit's amperage draw to ensure that your E30's electrical system can handle the additional load.

Wiring Harness

A dedicated wiring harness is essential for connecting the EPS unit to your E30's electrical system. You can either purchase a pre-made harness or create one yourself. A pre-made harness is generally easier to install and ensures proper connections, while a DIY harness allows for more customization.

The wiring harness should include connections for power, ground, ignition, and speed signal. The speed signal is crucial for providing variable assist, which adjusts the level of steering assistance based on the vehicle's speed. Without a speed signal, the EPS unit will provide maximum assist at all times, which can make the steering feel overly light at higher speeds.

Controller (if necessary)

Some EPS units require a separate controller to function properly. The controller is responsible for processing the speed signal and adjusting the level of steering assistance accordingly. If the EPS unit you choose requires a controller, make sure to source one that is compatible with the unit.

The controller should be mounted in a secure location and connected to the EPS unit and the vehicle's electrical system. Some controllers offer adjustable settings that allow you to fine-tune the steering feel to your liking. This can be a valuable feature for those who want to customize their steering experience.

Steering Column Adapter

To connect the EPS unit to your E30's steering column, you'll need a steering column adapter. This adapter ensures a secure and proper fit between the EPS unit and the steering column. You can either purchase a pre-made adapter or have one custom-fabricated.

The steering column adapter should be made from high-quality materials to ensure durability and reliability. It should also be precisely machined to ensure a proper fit and prevent any play or slop in the steering system. A poorly designed or manufactured adapter can compromise the safety and performance of the EPS system.

Fuse and Relay

To protect the EPS unit and your E30's electrical system, you'll need a fuse and relay. The fuse protects the EPS unit from overcurrent, while the relay provides a clean and reliable power source. Choose a fuse and relay with appropriate amperage ratings for the EPS unit.

The fuse and relay should be installed in a accessible location for easy maintenance and replacement. It's also a good idea to use a waterproof or weatherproof fuse holder to protect the fuse from the elements. Proper fusing and relaying are essential for ensuring the safety and reliability of the EPS system.

Step-by-Step Installation Guide

Now that you have all the necessary components, let's move on to the installation process. This step-by-step guide will walk you through the process of installing the electric power steering system in your BMW E30.

Step 1: Disconnect the Battery

Before starting any electrical work, it's crucial to disconnect the battery. This will prevent any accidental shorts or electrical shocks during the installation process. Locate the battery in your E30 and disconnect the negative terminal first, followed by the positive terminal.

Make sure to secure the battery cables so that they cannot accidentally come into contact with the battery terminals. This will prevent any potential hazards during the installation process.

Step 2: Remove the Steering Wheel

Remove the steering wheel from your E30. This will provide access to the steering column and make it easier to install the EPS unit. Use a steering wheel puller to safely remove the steering wheel without damaging the steering column or the steering wheel itself.

Before removing the steering wheel, mark its position on the steering column. This will help you align the steering wheel properly when you reinstall it later.

Step 3: Install the EPS Unit

Install the EPS unit onto the steering column using the steering column adapter. Ensure that the EPS unit is securely mounted and properly aligned. Tighten all bolts and fasteners to the manufacturer's specifications.

When installing the EPS unit, pay attention to the orientation of the unit. Some units have specific mounting orientations that must be followed to ensure proper operation. Consult the manufacturer's instructions for details.

Step 4: Wire the EPS Unit

Wire the EPS unit to your E30's electrical system using the wiring harness. Connect the power, ground, ignition, and speed signal wires to the appropriate terminals. Use a multimeter to verify the connections and ensure proper polarity.

When wiring the EPS unit, use high-quality connectors and terminals to ensure reliable connections. Solder the connections and use heat shrink tubing to protect them from corrosion and damage. Proper wiring is essential for the safe and reliable operation of the EPS system.

Step 5: Connect the Controller (if applicable)

If your EPS unit requires a controller, connect the controller to the EPS unit and the vehicle's electrical system. Mount the controller in a secure location and connect the power, ground, and signal wires to the appropriate terminals.

When connecting the controller, follow the manufacturer's instructions carefully. Incorrect wiring can damage the controller or the EPS unit. Double-check all connections before powering up the system.

Step 6: Install the Fuse and Relay

Install the fuse and relay in a accessible location and connect them to the EPS unit and the vehicle's electrical system. Ensure that the fuse and relay are properly rated for the EPS unit's amperage draw.

When installing the fuse and relay, use a waterproof or weatherproof fuse holder to protect the fuse from the elements. Proper fusing and relaying are essential for the safety and reliability of the EPS system.

Step 7: Reinstall the Steering Wheel

Reinstall the steering wheel onto the steering column, aligning it with the marks you made earlier. Tighten the steering wheel nut to the manufacturer's specifications.

After reinstalling the steering wheel, check for proper alignment and operation. Make sure that the steering wheel turns smoothly and that there is no play or slop in the steering system.

Step 8: Reconnect the Battery

Reconnect the battery to your E30. Connect the positive terminal first, followed by the negative terminal. Ensure that the battery cables are securely attached to the battery terminals.

After reconnecting the battery, check all electrical connections and verify that the EPS system is functioning properly. Start the engine and turn the steering wheel to check for smooth and consistent steering assistance.

Troubleshooting Tips

Even with careful installation, you may encounter some issues during or after the EPS conversion. Here are some troubleshooting tips to help you resolve common problems:

No Power

If the EPS unit is not receiving power, check the fuse, relay, and wiring connections. Use a multimeter to verify that power is reaching the EPS unit.

Erratic Steering

If the steering feels erratic or inconsistent, check the speed signal wire and the controller (if applicable). Ensure that the speed signal is being properly transmitted to the EPS unit.

Excessive Assistance

If the steering feels too light, especially at higher speeds, check the speed signal wire and the controller (if applicable). The EPS unit may be providing maximum assistance at all times due to a lack of speed signal.

Noise

If you hear unusual noises from the EPS unit, check the mounting bolts and fasteners. Ensure that the EPS unit is securely mounted and that there is no play or slop in the steering system.

Conclusion

Converting your BMW E30 to electric power steering can significantly enhance your driving experience. With improved efficiency, reliability, and customizable steering feel, an EPS conversion is a worthwhile upgrade for any E30 enthusiast. By following this comprehensive guide, you can confidently tackle the conversion process and enjoy the benefits of modern steering technology in your classic BMW.