The Honda S2000: A Platform Built for Revs

The Honda S2000 stands as an icon of Japanese sports car engineering. Its front-midship layout, near-perfect 50:50 weight distribution, and a naturally aspirated four-cylinder engine that revs past 9,000 RPM in the AP1 chassis set it apart from every other roadster of its era. The heart of the car—the F20C and later the F22C—is a masterpiece of airflow and combustion efficiency. However, like all production cars, the S2000 left the factory with compromises. The exhaust manifold, or header, is one of the most restrictive points in the stock system. Upgrading to a performance header is widely regarded as one of the highest-return modifications for the car. Among the available options, Megan Racing headers have earned a strong following for their balance of price, construction quality, and real-world gains. This article provides an in-depth look at Megan Racing headers for the S2000, covering design, installation, performance metrics, sound characteristics, and long-term ownership considerations.

Why Headers Matter: Stock Limitations and the Path to More Power

The factory header on the S2000 is a cast-iron log-style manifold. It is heavy, thermally inefficient, and its internal geometry creates significant backpressure. In a high-revving four-cylinder engine, exhaust scavenging is critical. The pulses of exhaust gases from each cylinder must exit quickly and without interference to allow fresh air-fuel mixture to enter the combustion chamber during the valve overlap period. The stock header's poor flow characteristics create a bottleneck that limits peak horsepower and delays throttle response.

Megan Racing headers address these shortcomings with a tubular equal-length design. Equal-length primary tubes ensure that exhaust pulses arrive at the collector at evenly spaced intervals. This minimizes pulse interference and improves scavenging efficiency. The result is a measurable reduction in backpressure, allowing the engine to spin more freely toward redline. Beyond raw power, the improved exhaust flow also reduces engine bay temperatures because heat exits the engine compartment more rapidly, which can positively affect intake air temperatures and overall engine longevity.

Megan Racing Header Options for the S2000

Megan Racing offers several header configurations for the Honda S2000, with variations in material, coating, and fitment depending on the model year. Understanding these differences is essential before making a purchase.

Material and Construction

All Megan Racing headers for the S2000 are constructed from mandrel-bent 304 stainless steel. This material offers excellent corrosion resistance and durability under high heat. The use of mandrel bending ensures that the inner diameter of the tubing remains consistent through every bend, preserving flow efficiency. The primary tubes on Megan Racing headers measure 1.75 inches in diameter, which is optimized for the F20C and F22C displacement and power characteristics. The headers feature a thick 5/16-inch flanged collector outlet that matches the stock catalytic converter or test pipe bolt pattern, simplifying installation.

Coating and Finish Options

Megan Racing headers are available in two primary finishes: raw stainless steel and ceramic-coated. The raw stainless steel option is more affordable and visually striking under the hood, but it tends to discolor over time from heat cycling. It also radiates more heat into the engine bay, which can affect intake temperatures and nearby components such as the alternator and wiring harness. The ceramic-coated version uses a high-temperature coating that reduces radiant heat transfer by a significant margin. This coating also resists discoloration and helps maintain exhaust gas velocity by keeping heat inside the primaries. For street-driven cars in warm climates or for those who track their vehicles, the ceramic coating is a worthwhile upgrade that costs slightly more.

Fitment: AP1 vs. AP2

The S2000 is divided into two primary chassis generations: the AP1 (2000–2003 in the US) and the AP2 (2004–2009). The F20C engine in the AP1 features a different intake manifold and camshaft profile than the F22C in the AP2, but the exhaust manifold mounting locations are identical. However, there are nuances in the oxygen sensor bung locations between model years. Megan Racing headers are designed to fit both AP1 and AP2 chassis, but early AP1 cars (2000–2001) may require a sensor extension harness because the primary O2 sensor location is positioned slightly differently. The header includes one bung for the primary O2 sensor and a second bung for the secondary sensor, which is used for emissions monitoring. The secondary bung is typically capped if the car retains a catalytic converter or used for a wideband sensor if the user has a standalone ECU. Megan Racing provides a detailed fitment guide with each header, and the company has a strong reputation for customer support regarding specific model-year questions.

Real-World Power Gains and Driveability

The claims of increased horsepower and torque are only meaningful when backed by independent testing. On a Dynojet dynamometer, a stock AP1 S2000 typically produces between 200 and 210 wheel horsepower. With a cold air intake and a Megan Racing header, that figure can rise to 215–225 wheel horsepower. Adding a high-flow catalytic converter or test pipe, along with a cat-back exhaust system, can push the total gain to 25–30 wheel horsepower over stock. While these numbers may seem modest compared to turbocharged platforms, the percentage increase is significant for a naturally aspirated four-cylinder engine. Moreover, the torque curve also benefits. The mid-range from 4,000 to 6,500 RPM sees gains of 8–12 lb-ft, which translates to stronger pull out of corners and improved overtaking capability on the highway.

One of the most notable characteristics of the Megan Racing header is that it does not sacrifice low-end drivability. Some header designs with excessively long primary tubes or poorly matched collectors can create a dip in torque below 3,500 RPM, making daily driving less pleasant. Megan’s primary tube length and collector design are well-matched to the S2000’s engine, preserving low-speed torque while unlocking top-end power. Throttle response becomes sharper, and the engine feels more eager to rev when the pedal is stabbed. This improvement is immediately noticeable, even to drivers who do not have a baseline dyno sheet.

Sound Quality: Aggressive but Refined

For many S2000 owners, the sound is as important as the power. The stock exhaust note is relatively muted, with a high-pitched but subdued tone. The Megan Racing header changes the acoustic character of the car dramatically. Without changing the rest of the exhaust system, the header adds a deeper, more aggressive note at idle and under load. The volume increases by about 30–40 percent at wide-open throttle, and the engine note develops a raspy edge in the upper RPM range that many enthusiasts find exhilarating. If the S2000 is equipped with a aftermarket cat-back exhaust, the sound becomes significantly louder, and drone on the highway can become an issue. For this reason, users who prioritize a refined daily-driving experience often pair the Megan header with a resonated test pipe or a cat-back system that incorporates a Helmholtz resonator or a large muffler core. The ceramic-coated header also contributes to a slightly quieter cabin experience because less heat and sound radiate into the engine bay. Overall, the Megan Racing header produces a sound that is race-inspired but not obnoxiously loud when paired thoughtfully with the rest of the exhaust system.

Installation Process and Practical Tips

Installing a header on the S2000 is a job that can be completed in a weekend with the right tools and workspace. The process is not overly complex, but working in the tight confines of the engine bay can test one’s patience. Following a structured approach increases the likelihood of a trouble-free install.

Tools and Materials Needed

  • Socket set with metric sizes (10mm, 12mm, 14mm, 17mm)
  • Torque wrench capable of reading in the 20–50 lb-ft range
  • Breaker bar and extensions
  • Penetrating oil (such as WD-40 or PB Blaster)
  • Jack and four jack stands
  • O2 sensor socket
  • Anti-seize compound for bolt reinstallation
  • New gaskets (included with some header kits, but OEM-grade replacements are recommended)
  • Optional: Impact wrench for stubborn bolts

Step-by-Step Guidance

Step 1: Preparation and Safety. Park the car on a level concrete surface. Disconnect the battery’s negative terminal. Raise the car and place it securely on four jack stands. Do not rely on a hydraulic jack alone. Allow the engine and exhaust system to cool completely if the car was running. Burns from touching a hot header are serious.

Step 2: Remove the Stock Header. Begin by removing the heat shield from the factory manifold. This shield is held by several 10mm or 12mm bolts. Once the shield is off, access the exhaust flange bolts connecting the header to the catalytic converter. These are often extremely tight and may require a breaker bar. Apply penetrating oil and let it soak for 10 minutes before attempting removal. Unbolt the header from the cylinder head. There are six bolts on the F20C and F22C. Work from the outer bolts inward to avoid warping the flange. Lower the stock header out from the bottom of the engine bay. It is tight, so rotate the header to find the correct extraction angle.

Step 3: Prepare the Megan Racing Header. Before installation, transfer the O2 sensors from the stock header to the Megan Racing unit. Apply a small amount of anti-seize to the sensor threads. If the Megan header has a removable collector gasket, ensure it is positioned correctly. Inspect the mating surfaces for any debris or burrs that could cause an exhaust leak.

Step 4: Install the New Header. Raise the Megan Racing header into position from below. It is advisable to have a helper to guide the header while you align the studs with the engine block flange. Install the six nuts by hand first, tightening them evenly in a crisscross pattern. Torque the nuts to 24 lb-ft for the cylinder head flange. Then, attach the header to the catalytic converter piping using the supplied hardware. Torque those bolts to 32 lb-ft. Do not overtighten, as the stainless steel bolts can strip the threads in the flange.

Step 5: Reinstall Heat Shields and Sensors. If the stock heat shield no longer fits, which is common with aftermarket headers, the ceramic coating on the Megan header will provide adequate protection. Some owners choose to wrap the header with exhaust wrap for additional thermal management, but this is optional and can accelerate corrosion if moisture is trapped. Reconnect the O2 sensors, ensuring the wiring is routed away from hot surfaces and moving parts.

Step 6: Final Checks. Start the engine and let it idle. Listen for any hissing or ticking sounds that indicate a leak. A soapy water spray bottle can help identify small leaks at the flange joints. Retorque the header bolts after the first heat cycle, as thermal expansion can loosen the fasteners. Finally, take the car for a short drive, then recheck all bolts once the engine has cooled.

Emissions and Regulatory Considerations

Megan Racing headers are not CARB-approved and do not carry an Executive Order number. This means they are not legal for street use in California and other states that follow CARB emissions standards. The header deletes the stock pre-catalyst and changes the O2 sensor location, which can trigger a check engine light (CEL) for catalyst efficiency below threshold. Many S2000 owners address this by tuning the ECU to disable the secondary O2 sensor monitor, or by using a mechanical spacer (often called a defouler) on the secondary O2 sensor. In regions without strict emissions testing, this is rarely an issue. However, owners should verify local regulations before installation. For track-only or off-road use, the Megan header is an excellent choice that improves both power and reliability by reducing under-hood temperatures.

Long-Term Ownership and Maintenance

The Megan Racing header is built to last, but longevity depends on environmental exposure and driving habits. In regions that use road salt during winter, the stainless steel can develop surface corrosion over time, though it will not rust through like mild steel. The ceramic-coated version is more resistant to this type of degradation. Regular inspection of the header bolts and flange gaskets is recommended every 15,000 miles or during major service intervals. Stainless steel fasteners can gall, so using anti-seize during installation is critical. Many owners have reported Megan Racing headers lasting over 100,000 miles without issues, provided that the initial installation was performed correctly and the system was not subjected to constant abuse from track driving without periodic checks. The header also does not interfere with oil changes or other routine maintenance once installed.

Comparisons with Competitors

The S2000 header market includes several notable players, including Toda Racing, J’s Racing, Spoon Sports, and Skunk2. Each brand approaches design differently. Toda and J’s Racing use thin-wall construction and proprietary collector shapes to maximize flow at extreme RPM, but their prices are significantly higher, often exceeding $1,500. Skunk2 offers a more affordable option similar to Megan Racing, but some users report fitment issues on early AP1 cars. Megan Racing strikes a position near the value end of the spectrum while delivering consistently good fitment and reliable performance. For the enthusiast who wants a significant performance upgrade without spending double the price, the Megan Racing header represents the best power-per-dollar ratio in the market. Independent dyno testing has shown that the difference between a Megan header and a top-tier Japanese brand is often only 3–5 horsepower, a gap that most drivers will never feel on the road.

Integration with Supporting Modifications

The true potential of the Megan Racing header is unlocked when combined with a complementary exhaust system and engine management. A typical naturally aspirated build for street use includes a cold air intake (such as AEM or K&N), the Megan header, a high-flow catalytic converter or test pipe, a cat-back exhaust, and a flash tune or piggyback ECU. This combination reliably produces over 230 wheel horsepower on an AP1, which is a 15–20 percent increase over stock. The drivability improvements are substantial, with crisp rev-matching on downshifts and a seamlessly linear power delivery to the 9,000 RPM redline. For those who plan to track their car, a tune that raises the redline to 9,200 RPM and adjusts fuel and ignition timing for the higher-flowing exhaust is a natural progression. The Megan Racing header has sufficient flow capacity to support engines with aftermarket camshafts and higher compression ratios, making it a versatile foundation for future upgrades.

Cost of Ownership and Return on Investment

Pricing for the Megan Racing header typically falls between $350 and $500, depending on the finish (raw vs. ceramic) and the retailer. This makes it one of the most affordable performance upgrades available for the S2000. Considering the horsepower gain of 10–15 wheel horsepower at the wheels with no other modifications, the cost per horsepower is remarkably low. Compared to a cold air intake alone, which might deliver 5 wheel horsepower for a similar price, the header offers double the gain. In terms of resale value, the S2000 aftermarket community is robust, and a well-maintained car with documented modifications can still command a premium if the parts are from reputable brands. Megan Racing headers are recognized as a quality aftermarket component, so the investment holds value better than generic parts. When the time comes to sell the car, the header can be removed, and the stock unit reinstalled, preserving the aftermarket part for a future project or sale to another enthusiast.

Final Verdict

The Megan Racing header for the Honda S2000 delivers on its core promises: a sporty exhaust note and a measurable increase in horsepower. It is a thoughtfully engineered product that respects the stock car’s balance while removing one of the most significant factory bottlenecks. The installation process is accessible to a competent home mechanic, and the long-term reliability is well-proven across thousands of vehicles. For the S2000 owner who wants more engagement from their car without venturing into forced induction or internal engine work, the Megan Racing header is a logical and rewarding upgrade. Paired with a tune and a free-flowing exhaust, it transforms the character of the S2000, making it feel sharper, quicker, and more alive. The sound alone will remind you why the S2000 remains a benchmark for naturally aspirated driving pleasure.