The Honda S2000 AP1 is a legendary sports car that continues to captivate enthusiasts with its 9,000-rpm redline and near-perfect 50:50 weight distribution. Yet even this iconic machine benefits from carefully chosen modifications. With a budget of $1,500, you can transform the driving experience without sacrificing reliability or daily usability. The key is selecting upgrades that deliver measurable gains in power, handling, or driver engagement. This guide covers eight high-impact modifications under $1,500, ranked by value and real-world results. Each section includes expected costs, installation tips, and links to trusted resources.

1. Cold Air Intake

A cold air intake is one of the simplest ways to unlock extra horsepower and sharper throttle response on the F20C engine. By relocating the air filter outside the engine bay or using a well-designed heat shield, the intake draws denser, cooler air. This reduces intake air temperatures and allows the engine to breathe more freely. Expect gains of 5–10 horsepower at the wheels, with the most noticeable improvement in mid-range torque.

Popular options for the AP1 include the AEM V2 and K&N Typhoon systems. The AEM uses a dry-flow filter and a sealed aluminum tube, while K&N offers a washable oiled filter for repeat use. Installation takes about one hour and requires only basic hand tools. Costs range from $200 to $400, making this one of the best value-per-dollar upgrades available.

For detailed dyno comparisons and installation guides, check out the S2Ki Performance Parts Forum – a treasure trove of real-world testing and owner feedback.

2. High-Performance Exhaust System

An aftermarket exhaust accomplishes three goals: increased power, reduced weight, and an exhilarating exhaust note. For under $1,500, a cat-back system is the most cost-effective option. It replaces the piping from the catalytic converter back to the tips, reducing backpressure and improving engine efficiency. Typical gains are 5–8 horsepower and 3–6 lb-ft of torque, though the biggest difference is the sound.

Brands like HKS Hi-Power, GReddy EVO 2, and Tanabe Medalion are well-regarded for the AP1. The HKS unit produces a deep tone without drone, while the GReddy offers a more aggressive note at high RPM. Most cat-backs weigh 10–15 pounds less than the stock exhaust, contributing to a slight reduction in curb weight. Expect to pay $500 to $800 for a quality system. Installation is straightforward with a jack and stands; allow 1–2 hours.

If your budget allows, consider a used exhaust from a reputable seller – many enthusiasts upgrade further and sell their gently used parts at a discount.

3. ECU Tune

The stock ECU leaves significant performance on the table due to conservative air-fuel ratios and ignition timing. A reflash or piggyback tuner unlocks the engine's true potential. For the AP1, the most popular solutions are EcuTek and Hondata FlashPro (with an adapter or for later models). Both allow tuners to adjust fuel maps, VTEC engagement, and rev limiters. Gains of 10–15 horsepower are typical, along with smoother power delivery and improved throttle response.

Costs vary from $300 for a mail-in reflash to $800 for a FlashPro with a custom tune from a professional. If you plan on adding an intake and exhaust later, a tune will maximize those mods. Keep in mind that the AP1's ECU is sometimes lockable; verify compatibility before purchase. Many tuners offer remote tuning via datalogging, making it convenient even if you don't live near a dyno.

For a comprehensive overview of S2000 tuning options, read the Ballade Sports ECU Tuning Guide. It explains the differences between reflashes, piggybacks, and standalone ECUs.

4. Upgraded Suspension Components

The AP1's double-wishbone suspension is already superb, but worn bushings and soft dampers dull its precision. With a $1,500 budget, you have several directions to go:

Sway Bars

Upgrading the front and rear sway bars reduces body roll and improves turn-in response. Eibach and Swift offer adjustable bars that let you fine-tune understeer/oversteer balance. Installation is simple and costs around $200–$400 for a set. This is the highest bang-for-buck suspension mod under $300.

Budget Coilovers

Coilovers replace the entire strut assembly and offer ride height and damping adjustment. For under $1,500, brands like BC Racing (BR series) and Tein Street Basis provide excellent value. You get lower center of gravity, reduced body roll, and the ability to dial in spring rates for track use. Expect to spend $800–$1,200. Installation is moderate – around 3–4 hours – but alignment is required afterward.

Polyurethane Bushings

Worn rubber bushings introduce slop in the suspension. Replacing key bushings – such as front lower control arm, rear toe arms, or differential mount – with polyurethane units sharpens feedback and maintains geometry under load. A complete bushing kit from HardRace or Energy Suspension costs $200–$400. This is a more involved install, best done with a press, but the results are transformative.

Combine sway bars with a mild drop from springs (like Eibach Pro-Kit) for a balanced budget setup. For detailed reviews, see S2Ki Brakes & Suspension Section.

5. Lightweight Wheels

Reducing unsprung weight is one of the most effective ways to improve acceleration, braking, and ride quality. For the AP1, swapping the heavy 16-inch factory wheels for lightweight aftermarket wheels can shed 8–12 pounds per corner. The Enkei RPF1 is the classic budget choice, weighing just 15.6 pounds in 17x9 ET45 (compared to 19 pounds for the stock wheel). Konig Hypergram and Rays 57DR are also popular options under $1,500 for a set.

Lighter wheels allow the suspension to react faster over bumps and reduce rotational inertia, making the car feel more agile. Expect to pay $600–$1,200 for a set of four depending on size and brand. Be aware of offset and hub bore compatibility – the AP1 uses 5x114.3 bolt pattern with a 64.1mm center bore. Many owners go for 17x8.5 or 17x9 to fit wider tires.

6. Performance Brake Pads

Stock brake pads fade quickly during aggressive driving or track sessions. Upgrading to a high-performance pad improves bite, fade resistance, and pedal consistency. Street-focused pads like Hawk HPS or EBC Yellowstuff are excellent for daily driving and occasional spirited runs. They cost $100–$150 per axle and work well with stock rotors.

For serious track use, consider StopTech Street/Track or Project Mu HC+ pads. These have a higher operating temperature and maintain stopping power under repeated heavy braking. They heat up within a few stops but can be dusty and noisy for daily use. Installation is straightforward – remove caliper, compress pistons, swap pads, and bed them properly. A proper bed-in procedure is crucial to avoid glazing.

7. Short Shifter Kit

Honda's cable-operated shifter is already praised for its precision, but a short shifter reduces the throw distance by 30–50%, making shifts quicker and more mechanical. Kits from TWM, Buddy Club, and C's Garage are popular among AP1 owners. They typically include a new shift lever, pivot bushings, and sometimes a lower arm for reduced friction.

Installation is moderate – requires removing center console and shifter assembly, about 1–2 hours. Costs range from $100 to $300. The main trade-off is increased effort; some drivers find notchy engagement with cheaper kits. Pair with an upgraded shifter base bushing for the best feel. This mod doesn't add horsepower, but it transforms the driving connection.

8. Lightweight Flywheel

The AP1's stock dual-mass flywheel weighs around 17–18 pounds. A single-mass lightweight flywheel cuts that to 8–10 pounds, dramatically reducing rotational inertia. The engine revs faster, throttle response improves, and the car feels more eager. Gains of 5–8 horsepower are reported from reduced drivetrain loss. ACT, Fidanza, and Exedy offer flywheels in the $200–$400 range.

Keep in mind that a single-mass flywheel can transmit more gear noise (gear rattle) at idle, which some owners find annoying. Also, it requires a compatible clutch for proper engagement. If your clutch is due for replacement, this is the perfect time to install a lightweight flywheel. Labor costs are significant (4–6 hours) if you pay a shop, but the driving change is profound.

Conclusion

The Honda S2000 AP1 responds beautifully to targeted modifications, and a $1,500 budget is enough to create a noticeably faster, sharper, and more engaging car. Start with a cold air intake and ECU tune for the best power gains. Then address handling with sway bars or budget coilovers. Finish with lightweight wheels and a short shifter for a pure driver's car feel. Remember to prioritize reliability – always buy from reputable sources and follow installation guides from the S2Ki community. With careful planning, these eight upgrades will keep you under $1,500 while elevating every aspect of the AP1 experience.