Honda Civic Si AWD – Your Ultimate Guide To Conversion, Care

Ever dreamt of transforming your nimble Honda Civic Si into an all-weather, all-terrain beast? You’re not alone. Many enthusiasts agree that the front-wheel-drive Si is a fantastic platform, but imagine the added grip, stability, and sheer fun an all-wheel-drive system could bring. The idea of a honda civic si awd conversion might sound daunting, perhaps even a little crazy, but we promise it’s a project that, with the right knowledge and dedication, is absolutely within reach for the experienced DIYer.

Here at FatBoysOffroad, we’re all about pushing boundaries and getting our hands dirty. This comprehensive guide will equip you with the insights, practical steps, and expert advice you need to tackle the exciting world of the AWD Si swap. We’ll cover everything from planning and execution to maintenance and even some sustainable modding tips, ensuring you have a reliable, high-performing, and unique machine.

honda civic si awd: The Dream Build Explained

The allure of a honda civic si awd lies in combining the Si’s lightweight chassis, rev-happy engine, and aftermarket support with the superior traction of an all-wheel-drive system. This isn’t just about going faster; it’s about unlocking new levels of control, especially in challenging conditions.

Why Go AWD with Your Si?

The benefits of honda civic si awd are numerous, extending beyond just straight-line acceleration.

Enhanced Traction: Distribute power to all four wheels, significantly improving grip in wet, snowy, or loose-surface conditions.
Improved Handling: Experience better cornering stability and reduced understeer, allowing for more aggressive and controlled driving.
Better Launch Control: Minimize wheel spin off the line, translating to quicker acceleration times.
Versatility: Transform your Si into a capable daily driver for all seasons or even a light off-road/rallycross contender.
Uniqueness: Stand out from the crowd with a truly custom and high-performance build.

The Core Components of an AWD Conversion

Understanding how to honda civic si awd begins with knowing the key components required. This isn’t a simple bolt-on affair; it involves integrating parts from other Honda/Acura vehicles known for their robust AWD systems, primarily the CR-V or Element.

Engine & Transmission: Your existing Si engine is likely suitable, but you’ll need an AWD-compatible transmission (e.g., K-series AWD transmission from a CR-V or Element).
Transfer Case: This unit attaches to the transmission and splits power between the front and rear driveshafts.
Driveshaft: Connects the transfer case to the rear differential. Custom fabrication is often required.
Rear Differential: Manages power distribution to the rear wheels. Again, CR-V or Element units are common donors.
Rear Subframe & Suspension: The FWD Si subframe won’t accommodate a rear differential. You’ll need to swap or heavily modify the rear subframe to accept the AWD components, often using CR-V or Element parts.
Rear Axles & Hubs: To deliver power to the rear wheels.
Fuel Tank Modification: The driveshaft often interferes with the stock Si fuel tank, requiring a custom or modified tank.

Planning Your Honda Civic Si AWD Conversion: Tips and Best Practices

Before you even pick up a wrench, thorough planning is paramount. This section offers essential honda civic si awd tips to ensure your project goes smoothly and safely.

Choosing Your Donor Vehicle

The success of your honda civic si awd conversion heavily relies on selecting the right donor parts. The 1st and 2nd generation Honda CR-V (RD1/RDX chassis) and the Honda Element are popular choices due to their compatible K-series engines and robust RealTime AWD systems.

CR-V/Element Generation: Research which specific year ranges offer the most compatible parts for your Si generation.
Condition of Donor Parts: Always inspect donor components thoroughly for rust, wear, and damage. A low-mileage donor vehicle is ideal.
Complete Drivetrain: Try to source as much of the AWD system from a single donor vehicle as possible to ensure compatibility and reduce guesswork.

Essential Tools and Workspace

A project of this magnitude requires more than just a basic toolkit. Here’s a rundown of what you’ll likely need:

Hydraulic Lift or Jack Stands: Absolutely essential for safe under-car access. Never work under a vehicle supported only by a jack.
Engine Hoist & Stand: For safely removing and working on the engine and transmission.
Comprehensive Socket & Wrench Set: Metric sizes will be your best friend.
Torque Wrench: Critical for ensuring all fasteners are tightened to manufacturer specifications. Don’t guess on critical suspension or drivetrain components.
Grinder, Welder, & Fabrication Tools: Likely needed for subframe modifications, driveshaft adaptation, and fuel tank work.
Air Compressor & Impact Tools: Can save significant time and effort.
Safety Gear: Eye protection, gloves, ear protection are non-negotiable.

Budgeting for Your Build

One of the most crucial honda civic si awd best practices is to establish a realistic budget. Conversions can quickly escalate in cost.

Donor Parts: Factor in the cost of the transmission, transfer case, differential, subframe, axles, and driveshaft.
Custom Fabrication: Account for labor and materials if you’re not doing all the welding and machining yourself.
Performance Upgrades: If you’re going AWD, you’re probably also thinking about more power. Factor in engine tuning, forced induction, or other performance mods.
Unexpected Costs: Always set aside an extra 10-20% for unforeseen issues, broken bolts, or parts you forgot.
Fluids & Consumables: Don’t forget new engine oil, transmission fluid, differential fluid, coolant, gaskets, and seals.

The DIYer’s Guide to an AWD Si Swap

This is where the rubber meets the road. While we can’t provide every single bolt-by-bolt instruction in this article, we’ll outline the major stages of how to honda civic si awd, offering a clear roadmap for your project.

Engine and Transmission Integration

The heart of your AWD conversion starts here. You’ll need to remove your Si’s FWD transmission and replace it with an AWD-compatible unit.

Remove Engine & Transmission: Safely disconnect all hoses, wiring, and mounts, then use an engine hoist to lift the engine and transmission out of the bay.
Separate Transmission: Detach the FWD transmission from your Si engine.
Install AWD Transmission: Mount the AWD transmission (e.g., CR-V K-series) to your Si engine. Ensure correct clutch and flywheel compatibility.
Install Transfer Case: The transfer case bolts directly to the AWD transmission, providing the output for the rear driveshaft.
Reinstall Engine & Transmission: Carefully lower the assembled engine/transmission/transfer case back into the Si’s engine bay. Reconnect all mounts, wiring, and hoses.

Subframe and Suspension Modifications

This is arguably the most challenging part of the conversion, as the FWD Si chassis was never designed for a rear differential.

Rear Subframe Removal: Remove the stock Si rear subframe, control arms, and suspension components.
Donor Subframe Adaptation: This typically involves using a CR-V or Element rear subframe. It will need significant modification, cutting, and welding to fit the Si chassis rails. This is a critical step that requires precision and strong welding skills. If you’re not an experienced welder, consider professional help.
Mounting the Differential: Once the subframe is adapted and mounted, the rear differential can be installed and bolted into place.
Suspension Installation: Install the rear control arms, shocks, and springs compatible with your adapted subframe.

Drivetrain and Axle Installation

With the major components in place, it’s time to connect everything.

Driveshaft Fabrication/Installation: A custom driveshaft is usually required to connect the transfer case to the rear differential. Measure precisely and have a reputable shop fabricate and balance it.
Rear Axles: Install the rear axles, connecting the differential to the rear hubs.
Front Axles: Install the front axles from your AWD transmission to the front hubs.

Wiring and ECU Considerations

The RealTime AWD system is mechanically actuated, meaning it doesn’t require complex electronic integration with your Si’s ECU for its basic function. However, if you’re looking for performance tuning or specific AWD engagement control, you might need to look into aftermarket ECUs or standalone controllers.

Fluid Lines: Ensure all fluid lines (brake, fuel) are routed safely and clear of the new drivetrain components, especially the driveshaft.
Speed Sensors: Verify that all speed sensors are correctly connected and functioning to prevent ABS or traction control issues.
Tuning: After the mechanical swap, proper ECU tuning is essential to optimize engine performance with the added drivetrain loss and potentially different gear ratios.

Maintaining Your Honda Civic Si AWD: Care Guide and Common Problems

Once your honda civic si awd beast is built, proper maintenance is key to its longevity and performance. This honda civic si awd care guide will help you keep it running strong.

Regular Maintenance Schedule

Your AWD Si will have specific maintenance needs that go beyond a standard FWD Civic.

Differential Fluid: Check and change your rear differential fluid regularly. Honda’s RealTime AWD system is sensitive to fluid quality. Refer to the CR-V/Element service intervals, usually every 15,000-30,000 miles. Use genuine Honda Dual Pump Fluid II.
Transfer Case Fluid: This also needs regular attention. Consult the donor vehicle’s service manual for specific intervals and fluid types.
Transmission Fluid: Maintain your AWD transmission with appropriate fluid changes, typically every 30,000-60,000 miles.
Driveshaft & Axle Inspection: Periodically check driveshaft U-joints, CV boots, and axle nuts for wear, looseness, or damage, especially if you engage in spirited driving or light off-roading.
Tire Rotation: Regular tire rotation is crucial for AWD vehicles to ensure even wear across all four tires. Uneven tire wear can put undue stress on the AWD system.

Addressing Common Drivetrain Issues

Even with meticulous care, custom builds can present unique challenges. Being aware of common problems with honda civic si awd conversions can help you troubleshoot efficiently.

Driveshaft Vibration: If you experience vibrations, especially at certain speeds, it could indicate an unbalanced driveshaft or incorrect installation angles. Have it professionally balanced.
Rear Differential Noise: Whining or clunking from the rear differential can signal low fluid, worn bearings, or gear damage. Address immediately to prevent catastrophic failure.
AWD Engagement Issues: If your AWD system isn’t engaging properly, check fluid levels, ensure the pressure switch (if applicable) is functioning, and inspect the differential’s internal components.
Tire Wear Sensitivity: As mentioned, AWD systems are sensitive to tire size and wear differences. Ensure all four tires are the same brand, model, and have similar tread depth.

Proactive Troubleshooting for Longevity

Listening to your vehicle is the best way to catch problems early. Pay attention to new noises, vibrations, or changes in handling.

Regular Inspections: Get under the car often. Look for leaks, loose bolts, worn bushings, or damaged components.
Fluid Checks: Make fluid level checks a routine part of your maintenance.
Professional Consultation: Don’t hesitate to consult with an experienced drivetrain specialist or a trusted mechanic if you encounter issues beyond your expertise. Knowing when to call a professional is a sign of a smart DIYer.

Beyond the Build: Performance and Sustainable Honda Civic Si AWD

Once you’ve achieved your honda civic si awd dream, the journey doesn’t end. There are always ways to refine performance and even consider the environmental impact of your custom build.

Tuning for Optimal Performance

With the added traction of AWD, your Si can handle more power. Custom tuning is essential to maximize your engine’s potential while ensuring reliability.

ECU Flash/Tune: Work with a reputable tuner who specializes in Honda K-series engines. They can optimize fuel maps, ignition timing, and VTEC engagement for your specific setup.
Dyno Testing: A dyno run will not only show you your power figures but also help the tuner identify and iron out any flat spots or issues in the power band.
Drivetrain Loss: Be aware that AWD systems inherently have more drivetrain loss than FWD. Don’t be discouraged if dyno numbers are slightly lower than a comparable FWD car; the real-world traction gains are where the AWD shines.

Eco-Friendly Modding and Driving Habits

Even performance builds can incorporate elements of sustainable honda civic si awd. Being an enthusiast doesn’t mean ignoring your environmental footprint.

Efficient Driving: While tempting to unleash all four wheels, practicing smooth acceleration and braking can significantly improve fuel economy.
Quality Parts: Investing in durable, high-quality aftermarket parts reduces the need for frequent replacements, saving resources in the long run.
Proper Waste Disposal: Always dispose of used fluids (oil, coolant, brake fluid) responsibly at designated recycling centers.
Regular Maintenance: A well-maintained engine runs more efficiently and produces fewer emissions.

Off-Road Setup Considerations

While a Civic Si isn’t a traditional off-roader, the AWD conversion opens up possibilities for light trails, gravel roads, or rallycross. For the off-road enthusiast in you, here are a few considerations:

Suspension Lift: A mild lift kit (1-2 inches) can provide crucial ground clearance for uneven terrain.
Skid Plates: Protect vital engine, transmission, and differential components from impacts.
All-Terrain Tires: Swapping to a more aggressive all-terrain or rally-style tire can greatly enhance grip on loose surfaces.
Reinforced Mounts: Consider upgrading engine, transmission, and differential mounts to handle the extra stress of off-road driving.

Frequently Asked Questions About the Honda Civic Si AWD

Is a Honda Civic Si AWD conversion expensive?

Yes, it can be quite expensive. Costs vary widely depending on whether you source used or new parts, the extent of custom fabrication needed, and if you’re paying for professional labor. Expect to spend several thousands of dollars, easily reaching upwards of $5,000-$10,000+ for a well-executed build.

How reliable is a converted AWD Si?

The reliability largely depends on the quality of the donor parts, the precision of the installation, and ongoing maintenance. If done correctly with strong components and proper care, an AWD Si can be very reliable. Poor execution or neglected maintenance will lead to frequent issues.

Can I convert any generation of Honda Civic Si to AWD?

While theoretically possible with enough fabrication, some generations are easier than others. The 8th (FG2/FA5) and 9th (FG4/FB6) generation Sis are popular choices due to the availability of K-series AWD transmissions from CR-Vs and Elements. Newer generations might require more custom work and adaptation.

Do I need to tune my engine after an AWD conversion?

Yes, absolutely. The added weight and drivetrain loss of an AWD system, along with potentially different gear ratios in the donor transmission, will require ECU tuning to ensure optimal performance, fuel economy, and engine longevity. Failing to tune can lead to poor performance or even engine damage.

What kind of performance gains can I expect from a honda civic si awd?

You might not see a significant increase in peak horsepower, but the primary gain is in usable power and traction. Expect drastically improved launches, better grip in corners, and superior performance in adverse weather conditions. The car will feel more planted and capable, especially if you add power later on.

Building a honda civic si awd is a monumental task, but the rewards are truly immense. It’s a project that tests your skills, expands your knowledge, and ultimately delivers a unique, high-performance machine that stands apart. Remember, safety always comes first, so take your time, double-check your work, and don’t be afraid to ask for help when needed.

Whether you’re tearing up the track, navigating snowy roads, or just enjoying the enhanced grip on your daily commute, your AWD Si will bring a smile to your face. Embrace the challenge, enjoy the process, and when it’s all done, you’ll have a ride that truly embodies the spirit of FatBoysOffroad. Stay safe and happy wrenching!

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Thomas Corle

Founder & Automobile expert at FatBoysOffroad

Automobile expert and off-road enthusiast, sharing in-depth knowledge of vehicles, gear, and adventures. Helping readers make smart decisions and enjoy the thrill of off-roading safely and confidently.