Upgrading your Mitsubishi Eclipse with a HKS Super Turbo Exhaust system is an excellent way to enhance both the vehicle's performance and its acoustic appeal. Not only does this aftermarket exhaust improve exhaust flow for increased horsepower and torque, but it also delivers a deeper, more aggressive sound that many enthusiasts desire. This comprehensive step-by-step guide will walk you through the entire installation process, from preparation to final testing, ensuring a smooth and successful upgrade.

Understanding the Benefits of the HKS Super Turbo Exhaust

Before diving into the installation, it’s important to understand why the HKS Super Turbo Exhaust is a popular choice among Mitsubishi Eclipse owners. This exhaust system is designed with high-quality stainless steel, offering durability against corrosion and heat. Its optimized piping diameter and mandrel bends reduce backpressure, which helps improve engine efficiency and power output. Additionally, the exhaust features a sporty yet refined sound profile that balances performance and everyday drivability.

Key Features

  • High-flow design: Enhances exhaust gas evacuation for improved engine breathing.
  • Stainless steel construction: Provides long-lasting resistance to rust and wear.
  • Sport-tuned muffler: Delivers a rich, deep exhaust note without excessive drone.
  • Direct bolt-on fitment: Simplifies installation with minimal modifications required.

Tools and Materials Needed

Gathering the proper tools and materials before starting the installation will save time and reduce frustration. Below is a detailed list of everything you’ll need:

  • HKS Super Turbo Exhaust Kit: Ensure you have the complete kit designed specifically for your Mitsubishi Eclipse model year.
  • Socket set and wrenches: Metric sizes typically ranging from 10mm to 17mm.
  • Screwdrivers: Both flathead and Phillips for clamps and brackets.
  • Jack and jack stands: For safely lifting and supporting the vehicle.
  • Ratchet and extensions: To reach bolts in tight spaces.
  • Penetrating oil (e.g., WD-40): Helps loosen rusted or seized bolts.
  • Rubber mallet or hammer: To gently tap exhaust components into alignment.
  • Torque wrench: For tightening bolts to manufacturer-specified torque values.
  • Safety gloves and glasses: Essential for hand and eye protection.
  • Anti-seize compound: Optional but recommended to apply on bolts to prevent future rusting.

Preparation

Proper preparation is critical for a smooth installation process. Follow these steps before removing the old exhaust system:

Step 1: Park and Secure the Vehicle

Park your Mitsubishi Eclipse on a flat, level surface, such as a garage floor or driveway. Engage the parking brake and place wheel chocks behind the rear wheels for added safety.

Step 2: Lift the Vehicle

Using the jack, carefully lift the front or rear of the vehicle depending on the exhaust layout. Consult your owner’s manual for recommended jacking points to avoid damage. Once elevated, position jack stands securely under the frame or designated support points to hold the vehicle in place. Never rely solely on the jack for support.

Step 3: Wear Safety Gear

Put on safety gloves and glasses to protect yourself from sharp edges, debris, and chemicals such as penetrating oil.

Step 4: Apply Penetrating Oil

Spray penetrating oil liberally on all bolts and nuts connecting the existing exhaust system. Allow it to soak for 10 to 15 minutes to loosen any rust or corrosion, which will make removal easier and reduce the risk of stripping bolts.

Removing the Old Exhaust System

With the vehicle safely lifted and prepared, you can now proceed to remove the stock exhaust. This process requires patience and care to prevent damage to surrounding components.

Step 1: Locate Exhaust Components

Slide under the vehicle and identify the key parts of the exhaust system: the catalytic converter flange, mid-pipe, resonator, muffler, and tailpipe. Refer to your vehicle’s service manual if needed.

Step 2: Disconnect Exhaust Sensors

If your Eclipse is equipped with oxygen sensors, carefully disconnect their electrical connectors. Label the sensors if necessary to ensure proper reinstallation.

Step 3: Unbolt the Exhaust Flanges and Clamps

Using the socket set and wrenches, remove all bolts and clamps securing the exhaust system. Start with the flange connecting the exhaust to the catalytic converter, then proceed toward the rear of the vehicle. Apply additional penetrating oil if bolts are stubborn.

Step 4: Remove Exhaust Hangers

The exhaust is typically held in place by rubber hangers attached to metal brackets on the vehicle’s chassis. Use a pry bar or exhaust hanger removal tool to detach these hangers. Be cautious not to damage the hangers if you plan to reuse them.

Step 5: Carefully Remove the Exhaust

Once all bolts and hangers are detached, carefully lower and remove the old exhaust system from under the vehicle. Having an assistant help support the weight is recommended to avoid dropping or bending the components.

Preparing the HKS Super Turbo Exhaust for Installation

Before installing the new exhaust, inspect all components included in the HKS kit. Lay them out and verify that all pipes, clamps, gaskets, and hardware are present and in good condition.

Step 1: Compare with Old Exhaust

Compare the new system’s layout and pipe diameters with the old exhaust to familiarize yourself with the fitment and any differences.

Step 2: Pre-assemble Sections

Partially assemble sections of the exhaust on the ground to check alignment, but do not fully tighten clamps or bolts at this stage. This will make final adjustments easier once the system is on the vehicle.

Installing the HKS Super Turbo Exhaust

With the old exhaust removed and the new system prepped, you can begin installation.

Step 1: Position the Exhaust

Starting at the front, position the HKS exhaust pipe onto the catalytic converter flange or mid-pipe, depending on your model. Slide the flange bolts through and loosely attach the nuts to hold the pipe in place.

Step 2: Attach Exhaust Hangers

Mount the exhaust hangers onto the vehicle’s rubber mounts. This supports the weight of the exhaust and helps maintain proper alignment.

Step 3: Connect Remaining Sections

Continue installing the exhaust sections from front to rear, aligning each pipe and muffler segment. Use supplied clamps and gaskets to ensure a proper seal and fit. Hand-tighten all fasteners initially.

Step 4: Check Alignment and Clearance

Ensure the entire exhaust system is positioned with adequate clearance from the underbody, suspension components, brake lines, and fuel lines. The exhaust should have some flexibility to move slightly without contacting other parts, preventing rattles or damage.

Step 5: Tighten Bolts and Clamps

Using your torque wrench, tighten all bolts and clamps to the manufacturer’s recommended specifications. Applying anti-seize compound to bolts during assembly can prevent future rust and ease disassembly.

Final Checks and Testing

Once the exhaust is fully installed and tightened, perform these final steps to verify a successful installation.

Step 1: Lower the Vehicle

Carefully lower the Mitsubishi Eclipse from the jack stands using the jack. Remove the jack stands and wheel chocks.

Step 2: Inspect for Visible Issues

Visually inspect the exhaust system for any signs of misalignment, loose clamps, or potential contact points.

Step 3: Start the Engine and Listen

Start your engine and listen for any exhaust leaks, which often manifest as hissing or popping sounds near joints. If leaks are detected, re-tighten clamps or adjust gaskets as needed.

Step 4: Monitor Exhaust Sound

Evaluate the exhaust note at idle and while revving the engine. The HKS Super Turbo Exhaust should deliver a deeper and more aggressive tone compared to stock while remaining smooth and not overly loud.

Step 5: Test Drive

Take your Eclipse for a short test drive, accelerating through various RPM ranges to ensure the exhaust functions correctly without rattles or unusual noises. Pay attention to performance improvements such as throttle response and engine sound.

Ongoing Maintenance and Care

To keep your HKS Super Turbo Exhaust in optimal condition, regular maintenance is recommended.

  • Periodic Inspections: Check the exhaust system for rust, cracks, or loose connections every few months.
  • Clean Exterior: Use mild soap and water to clean the exhaust tips, removing dirt and preventing corrosion.
  • Check Mounting Points: Ensure hangers and brackets remain secure to prevent excessive vibration or movement.
  • Monitor Performance: If you notice any changes in sound or engine behavior, inspect the exhaust for damage or leaks.
  • Follow Torque Specifications: Retighten bolts and clamps after the first few heat cycles, as thermal expansion can cause loosening.

Safety Tips and Best Practices

  • Always wear appropriate safety gear: Gloves, eye protection, and work clothes to protect against sharp metal and chemicals.
  • Use proper lifting equipment: Never work under a vehicle supported only by a jack; always use sturdy jack stands on a flat surface.
  • Work in a well-ventilated area: Exhaust fumes are hazardous; avoid enclosed spaces.
  • Follow manufacturer’s instructions: Adhere to all torque specifications and installation guidance provided with the HKS exhaust.
  • Dispose of old parts responsibly: Recycle or properly dispose of the old exhaust components.

Additional Tips for Enhanced Performance

For enthusiasts looking to further optimize their Mitsubishi Eclipse’s performance alongside the HKS Super Turbo Exhaust, consider the following upgrades:

  • High-flow catalytic converter: Reduces exhaust restriction for even better flow.
  • Performance air intake: Complements the exhaust by increasing air supply to the engine.
  • ECU tuning: Adjusts engine parameters to maximize gains from improved exhaust flow.
  • Upgraded headers: Further improve exhaust scavenging and power output.

These modifications should be carefully planned and installed in coordination with your exhaust upgrade for optimal results.

Conclusion

Installing the HKS Super Turbo Exhaust on your Mitsubishi Eclipse is a rewarding project that can significantly enhance your vehicle’s performance and sound. By following this detailed step-by-step guide, using the right tools, and adhering to safety practices, you can achieve a professional-quality installation that will provide years of driving enjoyment. Remember to perform regular maintenance and inspections to keep your exhaust system in peak condition.