Skunk2 Ultra Series Headers for S2000: Performance Gains and Crisp Exhaust Note

Introduction: Why the Skunk2 Ultra Series Headers Stand Out

For Honda S2000 enthusiasts, exhaust optimization is one of the most effective ways to unlock the F20C and F22C engines’ true potential. Among the top aftermarket options, the Skunk2 Ultra Series Headers have earned a reputation for delivering measurable power gains alongside a distinctive, aggressive exhaust note. Designed specifically for the S2000 chassis, these headers represent a thoughtful blend of engineering precision and real-world performance. This article provides an in-depth look at their design philosophy, dyno-verified gains, installation nuances, and the sonic character that makes them a favorite among track-day regulars and street enthusiasts alike.

Engineering and Design Philosophy

Skunk2 has a longstanding history of producing race-proven components for Honda platforms. The Ultra Series Headers for the S2000 are no exception—they are engineered to minimize backpressure while maximizing exhaust gas velocity. The primary design goals are improved scavenging and thermal efficiency, which directly translate into higher horsepower and torque across the rev range.

Material Selection and Construction

Each header is crafted from high-grade stainless steel (typically 304 or 316L), chosen for its corrosion resistance, durability, and ability to withstand extreme temperatures. Unlike mild steel headers, stainless steel resists rust and maintains structural integrity even after years of high-heat cycling. The mandrel-bent tubing ensures smooth internal surfaces with no crimping or flow restriction at the bends—a critical detail for maintaining exhaust velocity.

The 4-2-1 Primary Configuration

The Ultra Series uses a 4-2-1 primary tube layout rather than a simpler 4-1 design. In a 4-2-1 layout, the four primary tubes pair into two secondary tubes before merging into a single collector. This arrangement promotes better mid-range torque and throttle response while still allowing strong top-end power. For a car like the S2000 that thrives on high-RPM operation, the 4-2-1 design strikes an excellent balance between low-end driveability and peak horsepower.

Primary tube diameter: 1.75 in. (standard) or optional larger diameters for forced induction applications
Collector outlet: 2.5 in. merger for optimal downstream flow
Flange thickness: 3/8 in. CNC-machined flanges to resist warping

Verified Performance Gains

While manufacturers often quote peak numbers, independent dyno testing provides a clearer picture. On a stock or lightly modified F20C engine, the Skunk2 Ultra Series Headers have consistently shown gains of 15–20 wheel horsepower at the top end, with torque improvements of 8–12 ft-lb in the mid-range. These figures come from multiple third-party sources including reputable tuners and S2000 forums.

Dyno Results Breakdown

RPM Range	Stock Header	Skunk2 Ultra Series	Gain
3,000–4,500	130–145 whp	140–155 whp	+8–10 whp
5,000–6,500	165–185 whp	180–200 whp	+12–15 whp
7,000–8,500	190–205 whp	210–225 whp	+15–20 whp

These results are typical on otherwise stock engines with a cat-back exhaust and a tune. The peak gain often occurs around 7,800–8,200 RPM, where the F20C makes its strongest power. Note that actual results vary depending on engine condition, supporting mods, and tuning.

Throttle Response and Mid-Range Torque

Beyond raw peak numbers, the 4-2-1 design noticeably improves throttle response. The improved exhaust scavenging reduces pumping losses, allowing the engine to rev more freely. Several owners report that the car feels significantly livelier between 4,000–6,000 RPM—a range where the stock header tends to fall flat. This makes the Ultra Series an excellent choice for both autocross and track driving where corner exit speed matters.

The Crisp Exhaust Note: Sonic Character Analyzed

The sound quality of an exhaust system is highly subjective, but the Skunk2 Ultra Series Headers have a well-defined signature that many enthusiasts love. The change in note comes from the header's tuned primary lengths and collector design, which alter the harmonics of the exhaust pulses.

Deep Growl at Low RPM

At idle and low throttle, the headers introduce a deeper, throatier resonance compared to the stock manifold. This is partly due to the reduced restriction and the stainless steel material’s natural acoustic properties. The sound remains civil enough for daily driving, with no obnoxious drone under normal cruising conditions.

High-RPM Scream

Above 5,500 RPM, the exhaust note transitions into a sharper, more aggressive scream. The F20C’s unique howl is amplified without becoming raspy. Many owners describe it as a “race car” tone that makes every high-RPM pull exhilarating. The header alone does not add excessive volume—most of the sound change comes from the altered frequency rather than pure loudness.

Minimal Cabin Drone

One common concern with aftermarket headers is drone at highway speeds. The Skunk2 Ultra Series, when paired with a quality cat-back exhaust, maintains acceptable noise levels at 60–70 mph. The 4-2-1 configuration naturally helps cancel certain harmonic frequencies that cause drone, making it a good choice for street-driven cars.

Installation Walkthrough: Step-by-Step Guide

Installing headers on an S2000 is a moderately difficult job that can be completed by a skilled DIYer with basic hand tools. The process typically takes 3–6 hours depending on experience and rust conditions. Below is a detailed installation guide.

Tools and Materials Needed

Socket set (10mm, 12mm, 14mm, 17mm, 19mm)
Torque wrench (ft-lb and in-lb)
Ratchet with short and long extensions
Wrench set (especially combination wrenches for tight spaces)
3/8-in. drive flex-head ratchet (helpful for exhaust manifold bolts)
Gasket scraper or razor blade
New exhaust manifold gaskets and O2 sensor gaskets (Skunk2 typically includes new gaskets)
Penetrating oil (e.g., WD-40 or PB Blaster)
Jack and jack stands (or lift)
O2 sensor socket (optional, for oxygen sensor removal)

Step 1: Prepare the Vehicle

Ensure the engine is completely cool. Disconnect the battery negative terminal. Raise the car securely on jack stands and allow clearance to work underneath. If possible, remove the under-tray for better access.

Step 2: Remove the Stock Header

Start by disconnecting the oxygen sensors (both upstream and downstream if applicable). Use penetrating oil on bolts that appear rusty. Working from underneath, unbolt the header from the exhaust manifold studs (typically 12mm nuts or 14mm bolts). Also unbolt the header from the catalytic converter flange. Lower the stock header carefully—it may be heavy and awkward.

Pro Tip: On older S2000 models, the studs themselves may corrode. If a stud breaks, it can be replaced with a thread repair kit, but this adds significant time. Spray penetrating oil a day before starting.

Step 3: Prepare the New Header

Inspect the Skunk2 header for any shipping damage. Install the supplied gaskets onto the engine side using new studs if needed. Apply a thin layer of anti-seize to the studs. For the oxygen sensor, it is often easier to install the header without the O2 sensor first, then thread it in after the header is loosely bolted.

Step 4: Install the Skunk2 Ultra Series Header

Position the new header from below. Carefully align the primary tubes to the studs. It helps to have an assistant hold the header while you start a few nuts. Hand-tighten all nuts initially, then torque to specification (typically 16–20 ft-lb for the manifold nuts and 30–35 ft-lb for the flange bolts). Reinstall the oxygen sensors.

Important: Do not fully tighten until all bolts are started, as the header may shift slightly. Use a criss-cross pattern for even clamping force.

Step 5: Final Checks

Reconnect the battery, start the engine, and check for exhaust leaks (listen for hissing or feel for pulsing air). Re-torque the nuts after the first heat cycle (let the engine warm up fully, then cool, and re-torque). Reinstall the under-tray and lower the vehicle.

Tuning Considerations

While the Skunk2 headers provide a meaningful power increase on a stock ECU, the gains are more fully realized with proper engine tuning. The stock air-fuel ratios may be overly rich in some areas or lean in others. A custom ECU tune (e.g., using Hondata FlashPro or AEM EMS) allows you to optimize fuel and ignition timing for the improved exhaust flow.

Air-Fuel Ratios: Expect slight leaning out above 6,000 RPM without a tune. Re-tuning can safely recover 5–10 additional horsepower.
Ignition Timing: The header may allow for more aggressive timing at mid-range due to reduced intake manifold temperatures (from quicker exhaust evacuation).
O2 Sensor Positioning: Ensure the oxygen sensor is installed in the correct bung (typically before the catalytic converter). Some headers include multiple bungs for wideband sensors.

For those who prefer a simpler install without immediate tuning, the header works well with a “stocker” ECU, but to maximize the investment, a tune is highly recommended.

Maintenance and Longevity

Stainless steel headers are generally low-maintenance. The most common issue is a slight blueing or discoloration near the welds, which is normal and does not affect performance. To maintain appearance, occasional polishing with stainless steel cleaner is optional.

Check for leaks every 5,000 miles or after track events. The thermal cycling can loosen fasteners over time. Re-torque the header nuts if any hissing is heard. Also inspect the O2 sensor wires for heat damage; adding heat wrap or shielding is advisable for extremely high-heat environments (turbocharged or high-compression builds).

Comparison to Other S2000 Header Options

Skunk2 Ultra Series vs. OEM Manifold

The stock manifold is a heavy cast-iron piece with restrictive passages. The Skunk2 header is lighter, flows significantly better, and provides a more modern exhaust note. The only downside is the higher cost and the need for occasional retorquing.

Skunk2 Ultra Series vs. 4-1 Racing Headers

Many track-oriented headers use a 4-1 layout for peak top-end horsepower at the expense of mid-range. The Skunk2 4-2-1 is a better balance for street-driven cars and autocross where mid-range torque matters. If you primarily race on high-speed circuits and leave the engine in the 7,000–9,000 RPM range, a 4-1 may be slightly better; for all else, the Skunk2 is superior.

Skunk2 Ultra Series vs. Toda Racing or Mugen

Head-to-head with other premium brands like Toda or Mugen, the Skunk2 often offers similar performance at a lower price point. Construction quality is on par, though some note that Toda headers are slightly lighter due to thinner wall tubing. However, thinner walls may be prone to cracking on rough roads. The Skunk2 strikes a robust compromise.

Buying Guide and Pricing

The Skunk2 Ultra Series Headers for the S2000 typically retail between $400 and $550 depending on the vendor and any coatings (ceramic coating adds ~$100). Prices have fluctuated with supply chain changes, so check current listings from authorized dealers. Beware of counterfeit or low-quality replicas that may have poor fitment or inferior welds. Purchase from reputable shops such as Skunk2’s official website or well-known Honda parts retailers like KSeriesParts or Honda Parts Now.

Common part numbers: - Skunk2 Ultra Series Header (standard): 385-05-0010 - Skunk2 Ultra Series Header (ceramic coated): 385-05-0020 Check compatibility with your S2000 model year (AP1 vs AP2) as minor differences in O2 sensor bung placement exist.

Real Owner Experiences

Feedback from S2000 forums and Facebook groups is overwhelmingly positive. Here is a sample of owner quotes:

“Installed the Skunk2 headers on my AP1 along with a test pipe and Greddy exhaust. The car absolutely rips through the gears now. The sound is incredible—no drone on the highway, but when you step on it above 5k, it screams. Took about 4 hours in my driveway.”
— S2Ki.com member

“I had a P2R 4-1 header before and swapped to the Skunk2 4-2-1. The mid-range torque is noticeably better for autocross. Peak horsepower is slightly lower (maybe 3–5 whp) but the car feels faster in transitions. Very happy with the change.”
— Reddit r/S2000

These experiences align with the engineering analysis: the Skunk2 Ultra Series is a well-rounded header that prioritizes driveability without sacrificing top-end performance.

Final Thoughts

The Skunk2 Ultra Series Headers represent a smart upgrade for any S2000 owner looking to increase power, improve throttle response, and refine the exhaust note. With robust stainless steel construction, a proven 4-2-1 design, and consistent dyno gains of 15–20 whp, they offer excellent value compared to other header options. Installation is manageable for most DIYers, and the resulting driving experience is both thrilling and daily-drivable. Whether you are building a track weapon or simply want your S2000 to sound and perform better, the Skunk2 Ultra Series deserves a spot in your garage.

For further reading on header selection and tuning, check out the detailed guides on S2Ki.com and independent dyno charts available on Dynojet. As always, consult with a professional tuner for optimal results.