The Honda S2000 AP2 is a beloved sports car known for its high-revving engine and exceptional handling. Many enthusiasts seek to enhance its performance without extensive modifications. Simple bolt-ons such as the PRL intake and Invidia exhaust offer a proven way to add approximately 20 wheel horsepower, dramatically improving throttle response and the overall driving experience. This guide will explain how these mods work, what gains to expect, and what you need to know before installing them.

The S2000 AP2 Engine: A High-Revving Diamond

The AP2’s heart is the F22C1, a 2.2-liter inline-four that replaced the earlier AP1’s F20C. While peak power remained near 240 hp (at the crank), Honda engineers tuned the AP2 engine for more usable torque. The F22C1 produces roughly 162 lb-ft of torque compared to the F20C’s 153 lb-ft, with the peak arriving earlier in the rev range. This shift was achieved by increasing displacement from 2.0L to 2.2L and modifying the VTEC engagement point from 6,000 rpm (AP1) to around 5,800 rpm (AP2). The result is a broader, flatter torque curve that makes daily driving more pleasant without sacrificing the signature high-rpm thrill – the redline still sits at 8,200 rpm.

The engine’s dual-overhead camshafts and VTEC system allow it to breathe efficiently across the band. In stock form, the intake and exhaust are slightly restrictive to meet noise and emission regulations. This is where bolt-on parts come into play: they reduce restriction upstream and downstream of the combustion chamber, letting the engine operate more freely.

Common upgrades like the PRL intake and Invidia exhaust target these restrictions. Because the AP2 engine is already highly optimized, even small improvements to airflow yield noticeable power gains – usually in the double digits.

Why Bolt-Ons?

Bolt-on modifications are popular because they offer significant performance improvements without requiring engine disassembly. Installing an intake and cat-back exhaust typically takes a weekend with basic hand tools, and the modifications are fully reversible. They also tend to preserve reliability since the engine’s internal components are unchanged.

When chosen correctly, bolt-ons do not require a custom tune to see immediate gains. However, to unlock the maximum potential – especially when combining multiple parts – an ECU flash is highly recommended. We’ll cover that later.

The PRL Intake System

The PRL intake system, specifically their High Volume Intake (HVI) for the S2000, is a direct-fit cold air intake that replaces the restrictive factory airbox. PRL uses a large DryFlow filter with a silicone intake tube and a heat shield that seals against the hood. The design draws cool air from the front of the engine bay while blocking hot air from the radiator.

Benefits over the stock system include:

  • Improved airflow – The large filter and smooth mandrel-bent tube reduce turbulence and allow the engine to ingest more air per cycle.
  • Better throttle response – Less restriction means the throttle plate sees a more immediate pressure change when you step on the gas.
  • Enhanced induction sound – You’ll hear the VTEC crossover more clearly, adding to the driving experience.
  • Weight savings – The PRL HVI weighs less than the stock airbox assembly.

Installation involves removing the stock airbox, MAF sensor, and intake tube, then fitting the PRL pieces with provided hardware. No cutting or drilling is required. Most users report gains of 8–12 wheel horsepower from the intake alone when combined with a tune. On a stock ECU, the gain is slightly less – around 5–8 hp – but the improved response is immediately felt.

The Invidia Exhaust System

Invidia offers two main cat-back exhaust systems for the AP2: the Q300 (touring-style) and the N1 (race-style). Both are constructed from T-304 stainless steel with mandrel bends for smooth flow. The Q300 features mufflers designed to reduce drone while still improving exhaust velocity, while the N1 uses a straight-through muffler that prioritizes maximum flow and a louder tone.

Key performance features:

  • Reduced back pressure – The exhaust gases exit the engine more freely, which helps scavenge the cylinders and improves volumetric efficiency.
  • Weight reduction – The Invidia cat-back saves about 10–15 pounds over the heavy stock exhaust.
  • Power gains – On a dyno, the Q300 and N1 both add approximately 8–12 wheel horsepower when paired with an intake and tune.

The sound is more aggressive than stock, but the Q300 remains civil for daily driving with no highway drone. The N1 is louder and more track-oriented. Both are direct bolt-on replacements that include all gaskets and hardware.

Combined Power Gains: Dyno-Proven Results

When you install both the PRL intake and Invidia cat-back exhaust on a stock AP2, the combined effect is greater than the sum of each mod individually. The engine can breathe more freely at both ends, and the ECU adapts partially to the increased flow (though it is limited by the stock fuel and timing maps).

Independent dyno tests from sources like S2KI forums and performance shops show that an AP2 with these two bolt-ons typically gains 15–22 wheel horsepower. A common result is 19–20 whp with a baseline of around 195–205 whp (stock AP2s typically dyno 195–210 whp depending on the dyno). Peak torque gains are in the range of 12–16 lb-ft.

To achieve the full 20+ hp, a tune is not strictly required, but it is advisable. Without a tune, the ECU may add fuel in response to the extra airflow, causing a slightly rich condition that leaves some power on the table. With a Hondata FlashPro tune, those gains can increase to 22–25 whp, and the torque curve becomes smoother across the midrange.

Here is a typical dyno progression:

  • Stock AP2: 200 whp / 145 lb-ft (baseline)
  • + PRL intake only (with tune): 210–215 whp / 152–156 lb-ft
  • + Invidia exhaust only (with tune): 212–218 whp / 153–158 lb-ft
  • + Both (untuned): 215–222 whp / 156–162 lb-ft
  • + Both (tuned with FlashPro): 220–228 whp / 160–168 lb-ft

These numbers are from reliable sources; you can view a representative dyno graph on PRL’s product page.

Supporting Mods and Tuning

To maximize the investment, many owners add a test pipe (replacing the catalytic converter) or aftermarket headers. Headers such as the PLM or Toda can add another 5–10 hp, but they require more labor and may affect emissions legality. A test pipe or high-flow cat reduces restriction further and pairs well with the Invidia cat-back.

A Note on Tuning

While the intake and exhaust alone will give you a noticeable bump, an ECU tune unlocks their full potential. The Hondata FlashPro is the most popular tuning solution for the AP2. It allows a professional tuner to adjust fuel, ignition timing, VTEC engagement, and more. Typical gains from a tune on a bolt-on car are 5–10 whp over the untuned setup.

Tuning also ensures the air/fuel ratio remains safe. Without a tune, the engine runs slightly rich, which is conservative but not optimal for power. With a tune, you also get smoother part-throttle driving and can set VTEC to engage earlier for a more linear power delivery.

Installation Considerations

Installing the PRL intake and Invidia exhaust is straightforward. Here are key steps and tips:

  • Intake: Disconnect the battery (to reset ECU adaptations), remove the factory intake tube and airbox. Install the PRL heat shield, then the intake tube with MAF sensor. Tighten clamps securely. Reconnect battery.
  • Exhaust: Jack up the rear, support the stock exhaust with a jack stand under the muffler. Unbolt the midpipe from the catalytic converter and the hangers. Install the Invidia midpipe and muffler section, using new gaskets. Tighten bolts to 30–35 ft-lb.
  • Tools required: 10mm, 12mm, 14mm sockets, ratchet, wrench, penetrating oil for rusted bolts, jack and stands.
  • Professional help: If you lack tools or experience, a shop can do both installations in about 1–2 hours. Expect $150–$250 labor.

Always check for exhaust leaks after installation. A leak will cause a hissing sound and may reduce performance.

Cost and Value Analysis

Here’s a rough cost breakdown (prices may vary):

  • PRL HVI intake: $350–$400
  • Invidia Q300 cat-back exhaust: $900–$1,100
  • Invidia N1: $700–$900
  • Hondata FlashPro (with tune): $695–$850 + $400–$600 for dyno tuning

Cost per horsepower: With intake + exhaust alone (~20 hp) the cost is roughly $60–$75 per hp. Adding a tune (~25 hp total) brings the cost to about $85–$100 per hp, which is still very reasonable compared to forced induction or internal engine work. The improvements in sound and throttle response further increase the value.

Community Feedback and Real-World Results

The S2000 community on S2KI and dedicated Facebook groups overwhelmingly endorses these two mods as a “starter pack” for AP2 performance. Many members report seat-of-the-pants improvements after installation, especially in the mid-range where the car feels torquier. Common threads highlight that the PRL intake + Invidia Q300 combo is one of the most popular and reliable upgrades.

Several YouTube channels have documented dyno runs and driving impressions. For example, “S2000 AP2 PRL Intake & Invidia Exhaust Dyno” by Speed Academy shows a gain of 18 whp and 14 lb-ft on a baseline AP2. Another video by M539 Restorations covers installation and driving notes, noting the car feels “a lot more eager to rev.”

Overall, the consensus is that these bolt-ons deliver exactly what they promise: real, repeatable power gains with zero reliability issues when properly installed.

Conclusion

The Honda S2000 AP2 is a fantastic platform for performance modifications, and simple bolt-ons like the PRL intake and Invidia exhaust deliver a true 20-horsepower increase without breaking the bank or requiring engine surgery. Whether you’re a weekend racer or an enthusiast just looking for more smiles per mile, these parts are a proven upgrade that enhances the car’s already stellar character. For best results, pair them with a Hondata FlashPro tune – you’ll unlock the full potential of the F22C1 and make your S2000 even more exhilarating to drive.