So, you're thinking about transforming your Mazda RX8 into a road-racing beast? Awesome! The RX8, with its unique rotary engine and balanced chassis, is a fantastic platform for road racing. But, guys, it's not as simple as slapping on some stickers and calling it a day. Building a competitive RX8 road race car takes planning, dedication, and a healthy dose of mechanical know-how. This guide will walk you through the key areas you need to focus on to turn your RX8 into a track-day weapon. Let's dive in!

1. Engine Preparation and Enhancement

The heart of any RX8 road race car is, without a doubt, its rotary engine. The 13B Renesis engine is known for its high-revving nature and unique power delivery, but it also has its quirks. Reliability is paramount in racing, so this is where you'll want to invest significantly. Let's get into the details of what you need to do to make sure your rotary engine is ready for the track.

Rotary Engine Rebuild and Reinforcement

First and foremost, consider a complete engine rebuild. A fresh start ensures that you're working with components in optimal condition. When rebuilding, pay close attention to the following:

• Apex Seals: These are the most critical components for rotary engine reliability. Upgrade to high-performance aftermarket apex seals, such as those made from ceramic or carbon-reinforced materials. These seals can withstand higher temperatures and pressures, reducing the risk of failure under racing conditions. Seriously, guys, don't skimp on this! A blown apex seal can ruin your entire weekend, not to mention your engine.
• Side Seals and Corner Seals: Replace these seals as well. While not as prone to failure as apex seals, worn side and corner seals can lead to compression loss and reduced power. Go for quality aftermarket options designed for racing applications. These will help maintain consistent performance and reliability.
• Housings and Rotors: Inspect the rotor housings and rotors for wear and damage. Look for signs of chrome flaking or excessive wear on the rotor surfaces. If necessary, replace these components. Consider using ported rotor housings to improve airflow and increase power. Porting helps the engine breathe more efficiently, especially at high RPMs.
• Studs: Consider upgrading to stronger studs to handle the increased stress of racing. ARP studs are a popular choice. These studs offer superior clamping force and reduce the risk of head gasket failure, which can be a real headache.

Cooling System Upgrades

Rotary engines generate a lot of heat, so an upgraded cooling system is essential. Overheating can lead to serious engine damage, so it's better to be safe than sorry. Here’s what you should consider:

• Radiator: Install a high-capacity aluminum radiator. Aluminum radiators are much more efficient at dissipating heat than the stock radiator. Look for a radiator specifically designed for racing applications with increased core thickness and surface area.
• Oil Cooler: The RX8 already has an oil cooler, but upgrading to a larger, more efficient unit is highly recommended. Proper oil cooling is crucial for maintaining oil viscosity and preventing engine damage. Consider adding a second oil cooler for even greater cooling capacity.
• Thermostat: Use a lower temperature thermostat to help keep the engine running cooler. A lower temperature thermostat will open sooner, allowing coolant to flow through the engine and radiator earlier, preventing heat buildup.
• Coolant: Use a high-quality coolant designed for racing applications. These coolants offer better heat transfer properties and corrosion protection compared to standard coolants. Water Wetter is a popular additive that can further improve cooling efficiency.

Intake and Exhaust Modifications

To maximize power, you'll need to improve the engine's intake and exhaust flow. Here are some key modifications:

• Intake: Install a cold air intake system to increase airflow to the engine. A well-designed cold air intake will draw cooler air from outside the engine bay, improving combustion efficiency and power output. Consider using a larger diameter intake pipe and a high-flow air filter.
• Exhaust: Upgrade to a free-flowing exhaust system, including headers, a catalytic converter (if required by your racing class), and a cat-back exhaust. A less restrictive exhaust system will reduce backpressure and allow the engine to breathe more freely, resulting in increased power. Look for an exhaust system made from stainless steel for durability and corrosion resistance.

Engine Management

The stock ECU can be restrictive, so consider upgrading to a standalone engine management system. This will give you greater control over fuel delivery, ignition timing, and other engine parameters, allowing you to fine-tune the engine for optimal performance. Popular options include:

• Haltech: Haltech ECUs are known for their flexibility and advanced features.
• AEM: AEM ECUs are another popular choice, offering a wide range of features and tuning capabilities.
• Adaptronic: Adaptronic ECUs are a cost-effective option that still provides excellent control over the engine.

2. Suspension and Handling Upgrades

The RX8's handling is already quite good from the factory, but there's plenty of room for improvement when it comes to road racing. Upgrading the suspension and handling components will significantly improve the car's cornering ability, stability, and overall performance on the track. Let's break down the key areas to focus on.

Coilovers

Replacing the stock shocks and springs with a set of adjustable coilovers is one of the best things you can do for your RX8's handling. Coilovers allow you to adjust ride height, damping, and sometimes even camber, giving you precise control over the car's suspension setup. Look for coilovers with the following features:

• Adjustable Ride Height: This allows you to fine-tune the car's center of gravity and corner balance.
• Adjustable Damping: This allows you to control the stiffness of the suspension, affecting how the car responds to bumps and changes in direction.
• Spring Rate: Choose spring rates that are appropriate for your track and driving style. Stiffer springs will generally improve handling but can also make the ride harsher.

Anti-Roll Bars

Upgrading to stiffer anti-roll bars (also known as sway bars) will reduce body roll and improve the car's cornering ability. Stiffer anti-roll bars transfer more weight to the outside tires during cornering, increasing grip and reducing understeer or oversteer. Consider adjustable anti-roll bars, which allow you to fine-tune the car's handling balance.

Bushings

Replacing the stock rubber bushings with polyurethane or spherical bearings will improve suspension response and reduce unwanted movement. Rubber bushings can flex and deform under load, leading to imprecise handling. Polyurethane bushings are stiffer and more durable than rubber, while spherical bearings offer the ultimate in precision and minimal deflection.

Control Arms and Alignment

Consider upgrading to adjustable control arms to allow for more precise alignment settings. Adjustable control arms allow you to adjust camber, caster, and toe, which are crucial for optimizing the car's handling. A professional alignment is essential after making any suspension changes. Work with a shop that has experience setting up race cars to get the most out of your suspension upgrades.

Wheels and Tires

The right wheels and tires can make a huge difference in your RX8's performance. Lightweight wheels will reduce unsprung weight, improving acceleration, braking, and handling. Choose wheels that are strong and durable enough to withstand the stresses of racing. High-performance tires are essential for maximizing grip. Consider using racing slicks or DOT-approved racing tires for the best possible performance. Tire compound and size will depend on your track conditions and racing class regulations.

3. Braking System Enhancements

Stopping power is just as important as horsepower when it comes to road racing. Upgrading your RX8's braking system will improve its ability to slow down quickly and consistently, giving you more confidence on the track. Here's what you should focus on:

Brake Pads

Upgrade to high-performance brake pads designed for racing applications. These pads offer a higher coefficient of friction and can withstand higher temperatures than street pads. Look for pads with a consistent and predictable feel, even under heavy braking.

Brake Rotors

Consider upgrading to slotted or drilled brake rotors to improve cooling and reduce brake fade. Slotted rotors help to vent hot gases and debris away from the brake pads, while drilled rotors offer additional cooling. However, drilled rotors can be more prone to cracking under extreme heat, so choose wisely.

Brake Lines

Replace the stock rubber brake lines with stainless steel braided lines. Stainless steel lines expand less under pressure than rubber lines, resulting in a firmer and more responsive brake pedal feel.

Brake Calipers

If your budget allows, consider upgrading to larger brake calipers with more pistons. Larger calipers provide more clamping force, improving braking performance. Many aftermarket brake kits are available for the RX8.

Brake Cooling

Install brake cooling ducts to direct cool air to the brakes. Brake cooling ducts can significantly reduce brake temperatures, preventing brake fade and extending the life of your brake pads and rotors.

4. Safety Equipment

Safety should always be your top priority when building a road race car. Make sure your RX8 is equipped with the necessary safety equipment to protect you in the event of an accident. Here are the essentials:

Roll Cage

A roll cage is the most important safety modification you can make. A properly installed roll cage will protect you in the event of a rollover or crash. Make sure the roll cage meets the requirements of your racing organization.

Racing Seat and Harness

Replace the stock seat with a racing seat that provides better support and containment. A five- or six-point racing harness will keep you securely in the seat during hard cornering and in the event of an accident.

Fire Suppression System

Install a fire suppression system to quickly extinguish any fires that may occur. A fire suppression system can save your car and potentially your life in the event of a fire.

Window Net

A window net will prevent your arms from flailing outside the car in the event of a rollover or crash.

Kill Switch

Install a kill switch to quickly shut off the engine and electrical system in the event of an emergency.

5. Aerodynamics

Improving the RX8's aerodynamics can significantly improve its performance at higher speeds. Here are some key aerodynamic modifications to consider:

Front Splitter

A front splitter will create downforce at the front of the car, improving grip and reducing understeer.

Rear Wing

A rear wing will create downforce at the rear of the car, improving stability and reducing oversteer. Adjusting the angle of attack of the rear wing can fine-tune the car's handling balance.

Side Skirts

Side skirts will reduce airflow under the car, improving aerodynamic efficiency.

Undertray

An undertray will smooth out the airflow under the car, reducing drag and improving downforce.

Conclusion

Building an RX8 road race car is a challenging but rewarding project. By focusing on these key areas – engine, suspension, brakes, safety, and aerodynamics – you can transform your RX8 into a competitive track machine. Remember to prioritize safety, do your research, and don't be afraid to ask for help from experienced racers and mechanics. With the right preparation and dedication, you'll be tearing up the track in no time! Good luck, and have fun racing!