Overview of the HKS Spitzen Exhaust for the SW20 Turbo

The HKS Spitzen exhaust system is widely regarded as one of the most refined aftermarket upgrades for the SW20 Turbo (MR2 Turbo, 1990-1999). Designed and manufactured by HKS, a Japanese performance engineering company with decades of motorsport heritage, the Spitzen line delivers a balance of weight reduction, flow efficiency, and acoustic tuning that factory exhaust systems simply cannot match. For owners looking to unlock additional horsepower, sharpen throttle response, and achieve a deeper, more aggressive exhaust note without excessive drone, the Spitzen system remains a top-tier choice.

This guide provides a comprehensive, step-by-step walkthrough for installing the HKS Spitzen exhaust on your SW20 Turbo. Whether you are a seasoned DIY enthusiast or a first-time installer, following these instructions will help you complete the job safely and correctly. The article covers everything from pre-installation preparation and tool selection to torque specifications, post-installation checks, and ongoing maintenance. By the end, you will have the confidence to perform this upgrade yourself and enjoy the tangible benefits of improved performance and sound.

Tools and Materials You Will Need

Before beginning the installation, gather the following tools and supplies. Having everything on hand before you lift the vehicle will save time and reduce frustration.

  • HKS Spitzen Exhaust Kit — Verify that the kit includes the main muffler assembly, mid-pipe, all required gaskets, bolts, and washers. Inspect the parts for shipping damage before starting.
  • Socket Set — A metric socket set ranging from 10mm to 17mm, including extensions and a universal joint for awkward angles.
  • Combination Wrenches — 12mm, 14mm, and 17mm wrenches for bolts and nuts that are difficult to reach with a socket.
  • Jack and Jack Stands — A hydraulic floor jack and two or four jack stands rated for at least 2 tons. Safety is critical; never rely on a jack alone.
  • Penetrating Oil — A quality penetrating lubricant such as WD-40 Specialist or PB Blaster to loosen rusted or seized hardware.
  • Torque Wrench — A torque wrench capable of measuring in the range of 20-80 Nm (15-60 ft-lb) to properly tighten exhaust connections without over-stressing threads or flanges.
  • Safety Glasses and Gloves — Protect your eyes from debris and your hands from sharp edges and hot surfaces.
  • Metal File or Sandpaper — Useful for cleaning old gasket material or burrs from the turbo outlet flange.
  • Rags and Shop Towels — For wiping grease, dirt, and excess lubricant from components.

Preparation: Getting Your SW20 Turbo Ready

Proper preparation is the foundation of a smooth installation. Skipping these steps can lead to complications, especially when dealing with older vehicles where fasteners may be corroded or seized.

  • Park on a level surface and apply the parking brake firmly. Chock the rear wheels for added security.
  • Disconnect the negative battery terminal to prevent accidental short circuits or electrical damage while working near the engine bay and undercarriage.
  • Allow the engine to cool completely if it has been running. Exhaust components can reach temperatures exceeding 300°C (572°F) and will cause severe burns if touched while hot.
  • Spray all exhaust fasteners with penetrating oil 15-30 minutes before you begin. Focus on the bolts connecting the downpipe to the turbo, the mid-pipe flanges, and the muffler hangers. This will dramatically ease removal.
  • Inspect the existing exhaust system for signs of damage, rust-through, or leaks. Document any pre-existing issues with photos for your reference.
  • Clear your workspace of unnecessary items. Ensure you have room to move around the vehicle and safely operate a jack and stands.

Step-by-Step: Removing the Factory Exhaust System

Removing the stock exhaust is a straightforward process, but it requires patience and attention to detail, especially on higher-mileage vehicles. Follow these steps methodically.

Lift and Secure the Vehicle

  1. Using a hydraulic floor jack, lift the rear of the vehicle at the designated jacking point (consult your owner’s manual). Place jack stands under the reinforced frame rails or subframe connections. Lower the vehicle onto the stands and verify stability by gently rocking it.
  2. For additional clearance, you may also lift the front of the vehicle, but at a minimum the rear must be elevated to access the exhaust system comfortably.

Disconnect the Exhaust from the Turbo

  1. Locate the downpipe connection to the turbocharger outlet. This is typically secured by three or four 12mm or 14mm nuts. Apply additional penetrating oil if these fasteners appear heavily rusted.
  2. Using a socket with an extension and a universal joint if needed, carefully loosen and remove the nuts. If a nut threatens to strip, use a six-point socket and steady pressure rather than impact force.
  3. Gently separate the downpipe from the turbo studs. The exhaust system is heavy, so support it with a second jack or an assistant to prevent stress on other connections.

Remove the Mid-Pipe and Muffler Section

  1. Locate the flange connecting the downpipe to the mid-pipe, as well as the flange connecting the mid-pipe to the rear muffler section. Remove the bolts at each flange. Again, use penetrating oil and heat if necessary (a propane torch can break stubborn rust, but use caution near fuel lines and rubber hangers).
  2. Unhook the rubber exhaust hangers from the metal hangars using a pry bar or pliers. The rubber hangers are often pliable, but if they are aged and brittle, apply a small amount of silicone spray to ease removal.
  3. With all flanges disconnected and hangers released, carefully lower the old exhaust system from under the vehicle. This part is awkward and heavy, so having an assistant is recommended. Place the old exhaust aside for recycling or disposal.

Clean Flange Surfaces

Once the old exhaust is removed, inspect the turbo outlet flange and all intermediate pipe flanges. Use a metal file or sandpaper to remove any old gasket material, rust, or carbon deposits. Clean surfaces are essential for a leak-free seal with the new HKS Spitzen gaskets.

Installing the HKS Spitzen Exhaust System

With the old system removed and the flanges cleaned, you are ready to install the new HKS Spitzen exhaust. The fitment is engineered specifically for the SW20 Turbo, so the components should align without excessive force or modification.

Layout and Component Inspection

  1. Unbox the HKS Spitzen exhaust kit and lay out all components on a clean surface. Verify that you have the main muffler section, mid-pipe (if included), all gaskets, bolts, washers, and any instruction sheet provided by HKS.
  2. Dry-fit the components without tightening any fasteners. Align the mid-pipe to the downpipe flange, and then align the muffler section to the mid-pipe. Confirm that the exhaust tips are centered in the rear bumper cutouts. Adjust the position of rubber hangers as needed.

Installation Sequence

  1. Install the gaskets at each flange connection. The HKS kit typically includes high-quality metal or composite gaskets that withstand high temperatures and provide a reliable seal. Ensure the gasket faces are oriented correctly.
  2. Attach the mid-pipe to the downpipe outlet. Insert the bolts and hand-tighten them first. Use the supplied washers if included.
  3. Install the muffler section by connecting it to the mid-pipe flange. Hand-tighten the bolts. At the same time, attach the rubber hangers to the vehicle's metal hangars. You may need to use a small amount of soapy water or silicone spray to slide the rubber over the metal tabs.
  4. Once all components are aligned and hangers are seated, tighten all fasteners in a staggered pattern to evenly compress the gaskets. Use a torque wrench to tighten to the following specifications (unless otherwise noted in your HKS kit instructions):
    • Downpipe to mid-pipe bolts: 30-35 Nm (22-26 ft-lb)
    • Mid-pipe to muffler bolts: 25-30 Nm (18-22 ft-lb)
    • Muffler hanger bolts (if applicable): 15-20 Nm (11-15 ft-lb)
  5. Double-check all fasteners for proper torque. Re-verify that the exhaust does not contact the chassis, suspension components, or heat shields. Clearance should be at least 10 mm (3/8 inch) around all moving and hot components.

Final Adjustments

With the system fully tightened, have an assistant gently rock the vehicle while you observe the exhaust for any rattling or contact. If the exhaust tips are not centered, loosen the hanger connections slightly, adjust the position, and retighten. Patience at this stage pays off with a clean, professional-looking installation.

Post-Installation Checks and Testing

After the mechanical installation is complete, perform a series of checks before starting the engine. These steps will help ensure safety and optimal performance.

  • Reconnect the negative battery terminal and ensure it is snug.
  • Inspect the entire exhaust system from the turbo outlet to the rear tip. Verify that all bolts are tight and that no gaskets are pinched or misaligned.
  • Start the engine and let it idle. Listen for any abnormal sounds such as hissing, ticking, or rattling. A small amount of smoke or smell from oil residue on the new exhaust is normal and will burn off within a few minutes.
  • Check for exhaust leaks at each flange connection. You can do this by holding a gloved hand near the joints (careful of heat) or using a smoke machine if available. Even a small leak will reduce performance and produce an unpleasant sound.
  • Warm the engine to operating temperature and then carefully check for leaks again. Thermal expansion can cause gaskets to seat differently.
  • Take the vehicle for a short test drive on varied roads. Listen for drone at highway speeds, rattles during cornering, and overall sound quality. The HKS Spitzen is known for a deep, refined tone without excessive interior resonance, but personal preference may vary.

If you encounter any issues during testing, address them immediately. Loose fasteners can cause further damage to the exhaust or surrounding components. If a leak is detected, tighten the offending bolts slightly or replace the gasket if necessary.

Performance Benefits and Sound Characteristics

Beyond the installation procedure, understanding what the HKS Spitzen exhaust delivers can help you appreciate the upgrade. The Spitzen system is engineered with a straight-through muffler design that reduces backpressure while maintaining a refined acoustic profile. On the SW20 Turbo, this translates to measurable gains in horsepower and torque, particularly in the mid-to-high RPM range where the turbocharger is producing boost.

Typical dyno results from experienced owners show an increase of 5-10 horsepower at the wheels, depending on the condition of the rest of the engine and intake system. Throttle response sharpens noticeably, and the turbo spools more audibly. The exhaust note is deep and aggressive when accelerating but settles into a comfortable cruise at highway speeds, making it suitable for daily driving as well as track use.

For those considering additional modifications, the HKS Spitzen exhaust pairs exceptionally well with a high-flow downpipe, a boost controller, and an aftermarket intake. Together, these upgrades can transform the SW20 Turbo into a significantly more responsive and exciting vehicle while retaining excellent drivability.

Maintenance Tips for Longevity

The HKS Spitzen exhaust is constructed from durable materials including stainless steel and heat-treated alloys, but proper care will extend its life and preserve its appearance.

  • Regularly inspect the exhaust system for signs of corrosion, especially if you drive in regions where road salt is used in winter. Rinse the undercarriage periodically to remove salt deposits.
  • Check bolt torque after the first 500 km (300 miles) of driving. Vibration and thermal cycling can cause fasteners to loosen slightly. Re-tighten to the specified values as a matter of routine.
  • Clean the exhaust tips with a non-abrasive metal polish to maintain their luster. Avoid harsh chemicals that may damage the finish.
  • Listen for changes in sound that may indicate a developing leak or loose component. Early detection prevents more serious issues.
  • If you store the vehicle for extended periods, keep the exhaust dry and avoid exposure to moisture. A light coat of protective oil on the external surface can help prevent surface rust on mild steel components.

Frequently Asked Questions

Will the HKS Spitzen exhaust pass emissions testing?

The HKS Spitzen exhaust is a cat-back system, meaning it does not replace the catalytic converter. As long as your factory catalytic converter is functioning correctly, the system should not affect emissions test results. However, local regulations vary, so verify compliance in your jurisdiction before installing any aftermarket exhaust.

Does this exhaust require tuning?

No tuning is required for the HKS Spitzen cat-back exhaust alone. The modest performance gains are within the adaptive parameters of the factory ECU. If you combine the exhaust with a downpipe, intercooler upgrade, or boost controller, a custom tune is recommended to fully optimize the results.

How long does installation take?

A first-time installer with average mechanical skills can complete the job in approximately 2-4 hours. Allow extra time if rusted fasteners are encountered. Experienced mechanics can finish in 1-2 hours.

Can I install this exhaust without jack stands?

It is not recommended. Adequate clearance under the vehicle is required to work comfortably and safely. Jack stands are essential. Never work under a vehicle supported only by a hydraulic jack.

Final Thoughts

Installing the HKS Spitzen exhaust on your SW20 Turbo is one of the most rewarding upgrades you can perform. It combines measurable performance improvements with a sound that enhances the driving experience without being obtrusive. By following this comprehensive guide, you can complete the installation confidently and correctly, avoiding common pitfalls and ensuring a leak-free, long-lasting fit.

For additional technical resources and community support, consult reputable sources such as HKS's official product page for specifications, or visit the MR2 Owners Club forum for owner experiences and troubleshooting advice. If you are sourcing components, consider ordering from RHDJapan or Nengun Performance for genuine HKS parts. For installation tools and hardware, AutoZone provides a wide range of socket sets, torque wrenches, and penetrating oils suitable for this project.

Take your time, work methodically, and enjoy the process. The result will be a SW20 Turbo that sounds as fast as it truly is.