Ford Focus Rs Wide Body – Engineering The Ultimate Aggressively

Transforming your hot hatch with a wide body kit is about more than just aesthetics; it is about increasing the track width for superior grip and high-speed stability. This guide explores the technical nuances of selecting, fitting, and maintaining a wide body setup to ensure your RS performs as well as it looks.

You have likely seen them on the track or at local meets: that unmistakable, muscular silhouette that makes a standard hatchback look like a WRC contender. Many owners feel the stock RS is a bit too narrow for the power it puts down, leading to the desire for more rubber and a wider footprint. In this article, we will walk you through the entire journey of building a ford focus rs wide body that turns heads and shaves seconds off your lap times.

Whether you are a weekend DIYer or a dedicated track rat, cutting into your quarter panels is a daunting task that requires precision and the right mindset. We promise to provide the technical clarity and safety steps needed to navigate this modification without ruining your car’s structural integrity. Let’s dive into the world of flared arches and aggressive offsets.

Understanding the Core Purpose of a ford focus rs wide body Conversion

A ford focus rs wide body modification is primarily designed to accommodate wider wheels and tires that would otherwise poke past the stock fenders. This increased width lowers the car’s center of gravity relative to its track, significantly reducing body roll during hard cornering. For the AWD system in the Focus RS, having more mechanical grip means you can put the power down earlier when exiting a turn.

Beyond the performance gains, these kits provide a massive aerodynamic advantage if designed correctly. Wider fenders can incorporate vents that extract turbulent air from the wheel wells, reducing lift at high speeds. It is a functional upgrade that bridges the gap between a street-legal commuter and a purpose-built time attack machine.

However, you must remember that this is a permanent modification in most cases. You are not just bolting on parts; you are reshaping the vehicle’s architecture. Understanding the balance between form and function is the first step toward a successful build that maintains the car’s dynamic balance.

The Aesthetic Appeal vs. Aerodynamic Function

While many enthusiasts choose a wide body for the “clout” or visual presence, the best kits are wind-tunnel tested. A well-designed kit will manage the airflow around the rotating tires, which is one of the biggest sources of aerodynamic drag on a vehicle. Look for kits that include integrated splitters and diffusers to maximize these benefits.

If you are building a show car, you might prioritize seamless lines and molded fenders. If you are hitting the track, you might prefer exposed rivets for easier panel replacement after a “rub” with a tire wall. Both approaches are valid, but they require different installation techniques and materials.

Choosing the Right Materials: FRP, Carbon Fiber, and ABS

When shopping for your kit, the material choice will dictate the cost, durability, and ease of repair. Fiber-Reinforced Plastic (FRP) is the most common material because it is lightweight and relatively inexpensive to produce. It is easy to sand and paint, but it can be brittle and may crack under heavy vibration or minor impacts.

Carbon fiber is the gold standard for weight savings and structural rigidity. If you are building a high-end ford focus rs wide body, carbon fiber offers a weave that many choose to leave exposed for a high-tech look. However, it is significantly more expensive and difficult to repair if damaged on the road or track.

ABS plastic is often overlooked but provides excellent impact resistance. It is much more flexible than FRP, meaning it can take a hit from a rogue stone or a parking lot curb without shattering. While it is heavier than carbon, its durability makes it a favorite for daily-driven vehicles that see regular street use.

Weight Distribution Considerations

Adding a wide body kit adds weight to the outer edges of the car. While the panels themselves are light, the hardware, body filler, and wider wheels add up. Always aim for the lightest material your budget allows to keep the unsprung weight as low as possible for better suspension response.

Be mindful of how the extra width affects the car’s polar moment of inertia. While the wider track improves lateral grip, the added mass at the ends of the car can slightly change how the vehicle rotates in tight hairpins. Professional drivers often adjust their damping settings to compensate for these changes.

Step-by-Step Implementation: Installing a ford focus rs wide body

Before you pick up the grinder, you must perform a “dry fit” of every single panel. Use masking tape or Cleco fasteners to hold the flares against the body. This allows you to check the alignment with the doors, headlights, and fuel door to ensure everything lines up perfectly before making permanent cuts.

1. Mark Your Cut Lines: With the flares taped in place, mark a line about one inch inside the edge of the flare. This gives you enough metal to “tub” or weld the inner and outer fender skins back together.
2. The Point of No Return: Use an angle grinder with a thin cutting disc to remove the factory fender arches. Always wear eye protection and a face shield, as sparks will fly.
3. Sealing the Fenders: This is the most critical safety step. You must weld the inner and outer fender skins together or use a high-strength structural adhesive. If you leave a gap, moisture and road salt will enter the chassis, leading to catastrophic rust.
4. Rust Prevention: Apply a high-quality zinc-rich primer and seam sealer to all bare metal edges. This protects your investment and ensures the car remains structurally sound for years to come.
5. Final Mounting: Secure the panels using stainless steel rivets or specialized hardware like “Nutserts.” Apply a thin bead of rubber trim or silicone between the panel and the body to prevent paint chaffing and vibration noise.

Managing the Fuel Door and Sensors

One common challenge with the Focus RS is the fuel door location. Many wide body kits require a fuel door extension or a complete relocation of the hinge. Ensure the kit you choose provides a solution for this, or be prepared to do some custom fabrication to keep your refueling process painless.

Additionally, modern RS models have parking sensors and blind-spot monitors embedded in the bumpers. You will need to carefully drill holes in the new wide body bumper extensions to relocate these sensors. Failure to do so will result in dashboard error codes and the loss of safety features.

Wheel Fitment and Suspension Tuning for Wide Arches

Once the body is wide, your stock wheels will look “sunken” into the arches. To fix this, you need wheels with a much lower offset (ET). For example, if your stock wheels are ET50, a wide body might require an ET15 or even an ET0 to fill out the new flares properly.

Avoid using massive wheel spacers whenever possible. While a small spacer (5-10mm) is fine, huge bolt-on spacers put immense stress on your wheel bearings and can lead to premature failure. It is always better to buy wheels engineered with the correct width and offset for your specific kit.

You will also need to adjust your suspension. A wider track changes the scrub radius, which can make the steering feel heavier or more prone to “tramlining” (following ruts in the road). Upgrading to adjustable coilovers allows you to fine-tune the ride height and camber to optimize the tire’s contact patch.

Calculating the Perfect “Poke”

The goal is to have the tire sidewall sit flush with the edge of the fender flare. Use a plumb bob or a straight edge against the new flare to measure the distance to the wheel hub. This measurement, combined with your desired wheel width, will give you the exact offset you need to order.

Don’t forget about suspension travel. Just because it looks good parked doesn’t mean it won’t rub when you hit a bump at 60 mph. Always test the clearance by compressing the suspension fully (remove the spring from a coilover if necessary) to ensure the tire doesn’t hit the top of the arch.

Common Challenges and How to Overcome Them

The biggest challenge most DIYers face is paint matching. Even if you have the factory paint code (like Nitrous Blue), plastic panels often reflect light differently than metal. It is often best to have a professional body shop blend the paint across the doors and hood to ensure the ford focus rs wide body looks like it came from the factory.

Another issue is “panel gap” consistency. Because these kits are often handmade, they may have slight imperfections. Use a heat gun to gently warm the panels and reshape them if they don’t sit perfectly flush. Taking your time during the mock-up phase will save you hours of frustration during final assembly.

Lastly, consider the legality in your region. Some areas have strict laws about how far tires can protrude or how low a car can be. Always check your local transportation regulations to ensure your wide body RS remains street-legal and won’t get impounded during a routine traffic stop.

Protecting Your Investment

Wide body cars are magnets for rock chips. Because the fenders stick out further, they catch all the debris kicked up by the front tires. Installing a high-quality Paint Protection Film (PPF) on the leading edges of the rear flares is a “pro” tip that will keep your paint looking fresh for years.

Regularly check the mounting hardware. Vibrations from the road can loosen rivets or bolts over time. A quick inspection every time you change your oil is a great habit to ensure no panels become loose while you are driving at high speeds.

Future Trends and Upcoming Developments

The world of wide body styling is moving toward 3D scanning and printing. This allows for “perfect fit” kits that snap into place with OEM-level precision. We are also seeing a rise in active aerodynamics integrated into wide body kits, where flaps or wings adjust based on vehicle speed and braking force.

Sustainability is also becoming a factor. Manufacturers are experimenting with bio-based resins and recycled carbon fiber to reduce the environmental impact of these large aerodynamic components. As 3D printing technology becomes more accessible, we may see “printable” wide body files that owners can customize themselves.

Expect to see more integration with electric and hybrid powertrains as well. Future wide body designs will likely focus even more on cooling efficiency for battery packs and regenerative braking systems, blending the lines between styling and thermal management.

Frequently Asked Questions About ford focus rs wide body

Does a wide body kit void my Ford warranty?

Generally, yes, it will void the warranty on the body panels and potentially the suspension and wheel bearings. However, it should not affect the warranty on the engine or transmission unless those systems were modified during the installation. Always consult with your local dealer before proceeding.

Can I install a wide body kit by myself?

If you are comfortable using power tools, welding, and working with body filler, you can certainly do it. However, because it involves cutting the chassis, many people prefer to have a professional handle the metalwork and painting to ensure a concours-level finish.

How much does a full conversion cost?

A high-quality kit usually costs between $3,000 and $7,000. When you add in the cost of new wheels, tires, suspension, paint, and labor, a total ford focus rs wide body build can easily range from $10,000 to $20,000 depending on the quality of the parts used.

Is the modification reversible?

No, once you cut the factory metal fenders, there is no going back to stock without expensive and extensive bodywork. This modification is considered permanent, which can significantly affect the resale value of the vehicle, often limiting your market to other enthusiasts.

Final Thoughts on Your Wide Body Journey

Building a ford focus rs wide body is one of the most transformative things you can do to your car. It changes the vehicle’s personality from a subtle sleeper to a dominant presence on the road. While the process is intensive and requires a “measure twice, cut once” philosophy, the rewards in handling and aesthetics are unparalleled.

Always prioritize safety by sealing your cuts and ensuring your wheel fitment doesn’t compromise the car’s steering geometry. Take your time, use high-quality materials, and don’t be afraid to ask for professional help when it comes to the final paint and finish. Your RS is a special machine; treat it with the respect it deserves.

Stay safe, keep your eyes on the apex, and enjoy the incredible grip of your newly widened beast. The road is waiting—make sure you’re ready to dominate it!