Intake Upgrades: The Foundation of Airflow

Improving the intake system is often the first modification owners make to their S2000 AP2. The stock intake is designed for a balance of quiet operation and reasonable performance, but aftermarket options can unlock measurable gains in throttle response and top-end power. By reducing restriction and lowering intake air temperatures, these upgrades help the F22C1 engine breathe more freely.

Cold Air Intake Systems

A cold air intake relocates the filter outside the engine bay, drawing in denser, cooler air. For the AP2, popular kits range from $250 to $500. Brands like AEM, K&N, and HKS offer systems that replace the entire airbox and intake tube. Gains are modest—typically 5 to 8 wheel horsepower—but the improved induction sound is a frequent reason owners make the switch. Installation is straightforward and can be completed in under two hours with basic hand tools.

Intake Manifold Upgrades

For those chasing higher power targets, upgrading the intake manifold becomes relevant. Aftermarket options such as the Skunk2 Ultra Series or HyTech Motorsports units are designed to improve plenum volume and runner tuning. Prices range from $600 to $1,200. These manifolds shine in the upper RPM range, where the F22C1 already excels, and are best paired with a tune to realize their potential. Installation requires care with gasket sealing and vacuum line routing.

High-Performance Air Filters

Even without a full intake system, a drop-in high-flow air filter offers a low-cost improvement. Options like the K&N replacement filter or the HKS Super Hybrid Filter cost $50 to $100. They provide slightly better flow than the factory paper element and are reusable after cleaning. While the power gain is small, this upgrade is simple and pairs well with other intake modifications.

Exhaust System Upgrades: Flow and Sound

The exhaust system on the S2000 AP2 is a significant restriction in stock form. Upgrading the exhaust reduces backpressure and allows the engine to expel spent gases more efficiently. The result is a cleaner power curve and a more aggressive exhaust note. Many owners begin with a cat-back system and later add headers and a high-flow catalytic converter for a complete exhaust package.

Cat-Back Exhaust Systems

A cat-back exhaust replaces the piping and muffler from the catalytic converter rearward. Available in stainless steel or titanium, systems range from $500 to $1,500. Popular choices include the Greddy Supreme SP, HKS Hi-Power, and Invidia Q300. Weight savings can be significant—some titanium units drop over 15 pounds. Sound character varies widely, from deep and mellow to loud and raspy. Listen to clips before buying, as the AP2's dual exhaust design means sound is directly behind the cabin.

High-Performance Headers

Headers replace the restrictive factory exhaust manifold. For the AP2, designs are typically a 4-1 or 4-2-1 layout, with the 4-1 favoring top-end power and the 4-2-1 improving mid-range torque. Prices fall between $400 and $800. Brands like Toda Racing, Mugen, and J's Racing produce well-regarded units. Header installation is more involved than a cat-back, often requiring the removal of the intake manifold for access. Expect a gain of 8 to 12 wheel horsepower when paired with a tune.

High-Flow Catalytic Converters

A high-flow cat reduces backpressure while still meeting emissions requirements for street use. These units cost $200 to $600 and are often installed as part of a test pipe or full exhaust system. Brands like Berk Technology and Random Technology offer bolt-in replacements. Note that removing the catalytic converter entirely may cause a check engine light and is illegal for road use in many regions.

Engine Management and Tuning: Unlocking the Gains

Installing intake and exhaust parts without tuning leaves power on the table. The AP2's ECU uses closed-loop fuel and timing strategies that do not adapt well to increased airflow. A proper tune optimizes air-fuel ratios and ignition timing, ensuring the engine runs safely and efficiently. Tuning is essential when moving beyond basic bolt-ons and becomes non-negotiable with forced induction.

ECU Tune Options

For the S2000 AP2, several tuning platforms exist. The most common is a reflash or reprogramming of the factory ECU using tools like Hondata FlashPro or K-Pro. Costs range from $300 to $800 for the software and license, plus the calibration itself. Alternatively, standalone ECUs such as the AEM Infinity or Haltech Elite offer full control but at a higher price and complexity. A well-calibrated tune on a naturally aspirated AP2 can yield 10 to 15 wheel horsepower beyond the bolt-on parts alone.

Data Logging and Dyno Tuning Sessions

Data logging tools allow owners to monitor engine parameters and fine-tune calibrations. Entry-level options like the Hondata IMG unit cost $100 to $300. A professional dyno tuning session typically runs $200 to $500 per session, depending on the shop and region. Dyno tuning provides precise, repeatable results and is strongly recommended after any significant engine work. The combination of data logging and dyno time ensures the calibration is both powerful and reliable.

Forced Induction: The Path to Serious Power

For owners seeking power levels beyond 300 wheel horsepower, forced induction is the answer. The F22C1 engine responds well to boost, but the higher costs and mechanical complexity require careful planning. Both supercharging and turbocharging are proven paths, each with trade-offs in power delivery, installation difficulty, and maintenance.

Supercharger Kits

Supercharger kits for the AP2 deliver immediate, linear power that complements the F22C1's high-revving character. Centrifugal superchargers like those from Vortech or Kraftwerks are common, with prices ranging from $4,000 to $8,000. These kits typically include the supercharger unit, bracket assembly, intercooler, fuel injectors, and a tune. Installation is a weekend project for an experienced DIYer and can produce 320 to 380 wheel horsepower on a conservative tune. The supercharger whine is a bonus for many enthusiasts.

Turbocharger Kits

Turbocharger kits offer flexibility in power targets and a distinct boost curve. A complete kit from reputable builders like Full-Race or LoveFab costs $3,500 to $7,000. Turbo lag is minimal on the F22C1 due to its displacement, and spool is quick with a properly sized turbine. Power output can range from 350 to over 500 wheel horsepower, though supporting mods like forged internals become necessary at the higher end. Heat management is more demanding than with supercharging, requiring careful exhaust wrap, heat shielding, and oil cooling provisions.

Intercooler Upgrades

Regardless of forced induction type, intercooling is essential. Air-to-air intercooler core upgrades cost $300 to $1,000 and ensure intake air temperatures stay under control. A larger core reduces pressure drop and improves thermal efficiency. For street cars, a quality bar-and-plate intercooler from brands like Treadstone or Garrett is a wise investment. Owners pushing high boost should also consider a larger heat exchanger for liquid-cooled supercharger setups.

Suspension and Chassis Upgrades: Handling the Power

Adding power to an AP2 without addressing suspension is a common mistake. The S2000's double-wishbone suspension is excellent, but it benefits from upgrades that reduce body roll, improve damping, and provide adjustability. A well-sorted suspension transforms the car, making it more confidence-inspiring at speed.

Coilover Suspension Kits

Coilovers replace the factory struts and springs with height-adjustable, damping-adjustable units. Prices range from $1,000 to $2,500. Brands like KW, Ohlins, and BC Racing offer options suited for street or track use. Coilovers allow fine-tuning of ride height and corner balance, improving both aesthetics and handling. For daily driving, a street-focused coilover with progressive spring rates is recommended over a track-only setup that may be too stiff on rough roads.

Sway Bars and Strut Braces

Upgraded sway bars reduce body roll in corners, improving turn-in response and overall stability. Front and rear sway bar sets from Eibach or Whiteline cost $200 to $600. A strut tower brace, priced between $100 and $300, adds chassis stiffness and can improve steering feel. These upgrades are inexpensive relative to coilovers and provide noticeable handling improvements. Pairing a larger rear sway bar with a moderate front bar is a common setup for reducing understeer.

Brake System Upgrades: Stopping with Authority

As power increases, the demand on the braking system grows. The AP2's stock brakes are capable for street driving, but repeated high-speed stops or track use will overwhelm them. Upgrading pads, rotors, or the entire brake system is essential for safety and consistency.

High-Performance Brake Pads

The easiest brake upgrade is a set of high-performance pads. Street-performance compounds like Hawk HPS or EBC Yellowstuff cost $100 to $300 for a full set. These pads offer higher friction levels, better fade resistance, and improved initial bite compared to OEM pads. They also produce more dust, which is a trade-off for added performance. For track use, dedicated race pads are recommended and will require a separate set for street driving.

Slotted or Drilled Rotors

Slotted or drilled rotors improve heat dissipation and reduce pad glazing. Prices range from $200 to $600 for a full set. Slotted rotors are preferred over drilled rotors for track use due to the risk of cracking around the holes. Brands like StopTech and Brembo offer direct replacement sizes that fit the AP2 hub. Combining upgraded rotors with high-performance pads is a cost-effective way to improve braking.

Big Brake Kits

For serious track work or power levels above 350 wheel horsepower, a big brake kit is recommended. These kits replace the factory calipers and rotors with larger components, often using multi-piston calipers and oversized discs. Prices range from $1,500 to $3,000 for a front kit. Popular options include StopTech ST-40 and Wilwood kits. Big brake kits dramatically reduce stopping distances and provide consistent pedal feel even under extreme use. Installation requires at least 17-inch wheels to clear the larger calipers.

Conclusion

Building a performance Honda S2000 AP2 is a rewarding process, but the costs add up quickly. Starting with intake and exhaust upgrades provides a foundation for improved response and sound. Tuning is an essential step that maximizes the return on those parts. For owners chasing serious power, forced induction is the ultimate upgrade, with supercharger and turbocharger kits each offering distinct advantages. Suspension and brake upgrades ensure the car can handle and stop as well as it accelerates.

The total investment varies widely based on choices and labor. A basic bolt-on and tune package can be completed for around $2,000, while a full forced induction build with supporting suspension and brakes can reach $15,000 or more. Regardless of the path you choose, careful planning and quality parts will yield a car that is faster, more capable, and more enjoyable to drive. For further reading on parts selection and installation guides, consult resources like S2000.com and S2KI for community wisdom and build threads.