The S2000’s Quest for More Power

The Honda S2000 has earned a hallowed place among modern sports cars. Its F20C engine—one of the first production engines to surpass 120 hp per liter—delivers a visceral, 9,000-rpm symphony that few cars can match. Yet even the most dedicated S2000 owner eventually wonders what lies beyond the factory 240 hp. The car’s chassis is so capable that adding more power transforms it from a momentum car into a genuine straight-line threat while preserving its legendary cornering balance. Among the myriad forced-induction options, the Roots-type supercharger from Supercharger Unlimited stands out as a proven, street-friendly path to a reliable 320 hp.

This article explains how that power is achieved, what the installation involves, and what you can expect after the upgrade. Whether you are building a weekend track toy or a daily driver with bite, understanding the Roots supercharger’s advantages will help you make an informed decision.

What Is a Roots Supercharger and How Does It Work?

A Roots supercharger is a positive-displacement compressor that uses two counter-rotating lobes to trap and move air from the intake to the engine. Unlike a centrifugal supercharger (which builds boost progressively with engine speed) or a turbocharger (which relies on exhaust gas flow), a Roots blower delivers nearly instantaneous boost pressure across the entire rev range. This characteristic makes it ideal for the S2000’s high-strung powerband because it fills the low and mid-range torque hole that many naturally aspirated Hondas suffer from.

Supercharger Unlimited’s Roots kit for the S2000 is engineered to bolt onto the stock intake manifold location with minimal modifications. The unit itself is compact and robust, featuring precision-ground rotors and sealed bearings that require no oil supply from the engine. It spins off the crankshaft via a serpentine belt drive, with an integrated bypass valve to limit parasitic loss when cruising.

Key design features include:

  • Belt-driven boost – no exhaust plumbing, no lag, no heat soak from a hot turbine housing.
  • Whipple-style twin-screw option – though technically a twin-screw, its operating principles are similar, and Supercharger Unlimited offers both Roots and twin-screw kits. For this article, we focus on their Roots variant, which provides a linear, predictable power curve.
  • Integrated charge air cooler – the intake air is routed through an air-to-air intercooler to keep charge temperatures manageable, ensuring consistent power during sustained pulls.
  • Plug-and-play hardware – all brackets, pulleys, belts, and fittings are included; the kit is designed for S2000 models from 2000 through 2009.

For a deeper dive into the engineering of Roots-type superchargers, Supercharger Unlimited’s technology page provides detailed diagrams and performance data.

Why Choose a Roots Supercharger Over a Centrifugal or Turbo Setup?

Each forced-induction method has its strengths. A centrifugal supercharger can make impressive peak power, but it often sacrifices low-end torque. A turbocharger can deliver massive top-end numbers, but it introduces lag, requires oil and water lines, and generates significant underhood heat. The Roots supercharger strikes a balance that many S2000 owners find ideal:

  • Instant throttle response – no spool time. Mash the pedal from 2,500 rpm and the car surges forward, not just from 6,000 rpm upward.
  • Linear power delivery – the torque curve is fat and flat, making the car easier to drive fast on track and more enjoyable on the street.
  • Lower intake air temperatures (IATs) than a top-mounted turbo, especially with the included intercooler.
  • Simpler installation – no welding of exhaust manifolds, no oil drain lines, no intercooler piping that snakes across the engine bay.

Many owners report that after driving a Roots-supercharged S2000, they never want to go back to naturally aspirated. The extra torque transforms the car’s character without ruining its rev-happy personality.

The 320 hp Target: What Does It Mean in Real-World Terms?

Stock S2000s (AP1 and AP2) produce 237–240 hp at the crank depending on the model year. A Roots supercharger from Supercharger Unlimited typically adds 80–85 wheel horsepower on a conservative tune, translating to roughly 315–325 crank horsepower—hence the “320 hp” claim. But numbers alone don’t tell the full story.

Drivability changes:

  • 0–60 mph drops from the mid-5-second range to the low 4-second range with a good launch.
  • In-gear acceleration from 40–80 mph improves dramatically. Passing on two-lane roads becomes effortless.
  • Track lap times improve due to better corner exit speeds. You no longer have to hold a gear waiting for VTEC; the boost is there from the moment you roll into the throttle.

We recommend reading S2KI’s forced induction forum for owner dyno sheets and first-hand comparisons. Many threads document back-to-back pulls between stock and Roots-supercharged cars.

Installation: Step-by-Step Overview

While the article you provided lists installation steps generically, here we expand with details specific to the Supercharger Unlimited kit. The entire process can be completed in a weekend by an experienced DIYer, or in one day at a shop.

Preparation and Tools

You’ll need standard hand tools, a torque wrench, coolant, and a laptop with tuning software (or a pre-flashed ECU from Supercharger Unlimited). The kit includes a new intake manifold, supercharger unit, belt, intercooler, and all necessary hardware.

Disassembly

Remove the factory intake airbox, intake manifold, and throttle body. Drain the coolant if the system includes a water-to-air intercooler; for air-to-air units, coolant drains are not needed. Support the engine with a jack as you may need to lower it slightly to access the manifold bolts.

Supercharger Mounting

Bolt the supercharger bracket to the engine block. Install the supercharger onto the bracket and align the pulley. The supplied belt tensioner ensures proper deflection. Connect the bypass valve vacuum line to a manifold pressure source.

Intercooler and Piping

Mount the intercooler in front of the radiator or in the driver-side fog-light area, depending on the kit variant. Run the charge pipes from the supercharger outlet to the intercooler, then to the throttle body. Use silicone couplers and T-bolt clamps for a leak-free seal.

Reassembly and Tuning

Reinstall the throttle body, reconnect sensors, and fill any coolant or oil lines. Double-check belt tension. Most importantly, the ECU must be recalibrated. Supercharger Unlimited offers a mail-order reflash or a handheld tuner. You can also visit a local dyno tuner with experience on Honda standalone ECUs (e.g., Hondata FlashPro or MoTeC).

“The tune is critical. A conservative air-fuel ratio and proper ignition timing ensure the engine lives a long life. Do not skip this step.” – John W., S2000 owner and Builder

Supporting Modifications You Should Consider

To safely handle 320 hp, the stock S2000 needs a few supporting upgrades:

  • Fuel system: At 320 hp, the stock fuel pump and injectors may be at their limit. Upgrading to a Walbro 255 lph pump and 550–750 cc injectors is cheap insurance.
  • Clutch: The stock clutch will slip under hard acceleration. A Stage 2 or Stage 3 clutch (such as Competition Clutch or ACT) is recommended.
  • Cooling: A higher-capacity radiator and a lower-temperature thermostat help manage the extra heat. Some owners also add an oil cooler.
  • Tires: With more torque, the stock all-season tires will struggle for grip. 255-width summer tires on the rear are a typical upgrade.

For a comprehensive build list, Supercharger Unlimited’s supporting mod guide is a great resource.

Cost Considerations

The Roots supercharger kit from Supercharger Unlimited typically retails between $4,500 and $5,500 depending on the intercooler configuration and included options. Installation at a reputable shop adds $800–$1,500. Tuning another $400–$800. Supporting mods (clutch, fuel, cooling) can add $1,500–$3,000. Total investment: roughly $7,500–$11,000. While not cheap, it’s one of the most cost-effective ways to add 80 reliable horsepower to an S2000—far cheaper than an engine swap or turbo build with similar reliability.

Maintenance and Longevity

Roots superchargers are known for their durability. The Supercharger Unlimited kit uses sealed bearings that require no maintenance for the first 60,000 miles. Change the belt every 30,000 miles or sooner if you track the car heavily. Change the engine oil more frequently—3,000–4,000 miles—since forced induction increases oil contamination. Regularly inspect the bypass valve diaphragm and charge pipes for leaks.

Many owners report 50,000+ trouble-free miles on their roots-supercharged S2000s with proper tune and maintenance. The engine internals (rods, pistons, crankshaft) are stout enough for 350 hp without rebuilding, so 320 hp is within a safe margin.

Real-World Owner Experiences

To give you a sense of what it’s like to live with this setup, here are snippets from S2KI forum members:

  • “I was worried about losing the high-rev magic, but the Roots blower actually makes VTEC even more addictive. You get the torque everywhere, then VTEC kicks in and it’s like a second rush. Best mod I’ve ever done.”
  • “Took my car to the drag strip. With sticky tires and a good launch, I ran 12.7 @ 111 mph on the stock motor. It was completely reliable all day.”
  • “The kit was easy to install—I did it in my garage over a weekend. The instructions were clear. The customer support from Supercharger Unlimited was excellent when I called about belt alignment.”

Conclusion

A Roots supercharger from Supercharger Unlimited delivers exactly what the S2000 needs: more usable power without sacrificing the engine’s soul. By boosting output to 320 hp, you gain a car that is significantly faster in every meaningful metric while retaining the sharp handling and 9,000-rpm thrill that make the S2000 special. The installation is straightforward, the supporting parts are well-documented, and the results are proven by hundreds of owners.

If you are ready to take the plunge, start by reading the complete kit details on Supercharger Unlimited’s site. Then join the S2000 community discussions to see dyno charts and ask questions from others who have already built their dream car. With careful planning and proper tuning, your S2000 can reach that 320 hp milestone—and become an even more exhilarating machine to drive.