Competition Clutch Lightweight Flywheel for Honda S2000

Competition Clutch Lightweight Steel Flywheel for Honda S2000

At 11.5 lbs, the Competition Clutch ST flywheel (2-669-ST) is the one most S2000 owners should actually buy. It cuts real weight off the stock flywheel (the AP1 unit weighs about 14 lbs, the AP2 is over 21 lbs) while keeping the car completely livable on the street. You'll feel the difference in throttle response and shift quality without turning your daily commute into a workout.

Competition Clutch makes two versions for the S2000: this ST (lightweight) at 11.5 lbs and the STU (ultra-light) at 9.25 lbs. The ST is designed for naturally aspirated and street-driven cars. It pairs with stock, Stage 1, and Stage 2 clutch kits. If your S2000 sees regular street driving, weekend canyon runs, and occasional track days, this is the better match. The STU is purpose-built for dedicated track cars, forced induction builds, and Stage 3+ clutch setups where the drivability trade-offs don't matter.

Why 11.5 lbs Is the Sweet Spot for Most S2000 Builds

There's a common misconception that lighter is always better with flywheels. It's not. Go too light on a street car and you end up with rough idle, excessive gear chatter, stalling at low speed, and a car that fights you in stop-and-go traffic. The S2000 community has been having this debate for over 20 years, and the consensus is clear: somewhere in the 10-12 lb range is where you get the biggest improvement in feel without making the car annoying to live with.

For AP2 owners especially, the math is dramatic. You're dropping almost 10 lbs of rotating mass off the crankshaft. That's a 45% reduction from the 21 lb stock AP2 flywheel. You'll feel it immediately: faster revs, quicker rev drop between shifts, sharper heel-toe, and an engine that feels more willing to chase VTEC. But your first gear takeoffs will still feel natural, idle stays smooth, and you won't dread sitting in traffic.

AP1 owners are coming from a lighter starting point (~14 lbs), so the change is more subtle, roughly 2.5 lbs. You'll still feel an improvement in throttle response and rev matching, but the biggest gains here are in construction quality and the SFI safety certification for track use.

How It Compares to Other S2000 Flywheel Options

The Competition Clutch ST and ACT Streetlite are the two closest competitors at this weight class. Both are forged steel, one-piece designs at nearly identical weights. The Competition Clutch uses 4140 steel while the ACT uses chromoly. Both are SFI certified. The ACT has induction-hardened ring gears, while the Competition Clutch uses an integrated one-piece ring gear. In practice, both are well-proven in the S2000 community and you won't go wrong with either. The CC ST is typically easier to find at MAP ($350) while the ACT price varies more between retailers ($317-$407).

Construction

• 4140 Forged Steel
  Stamped under 2,000 tons of pressure at 1,260°F. This is the same steel alloy used across serious motorsport applications. It's tough enough to handle repeated high-RPM abuse and can be resurfaced when you swap clutches, so you don't have to buy a new flywheel every time.
• One-Piece Integrated Ring Gear
  The ring gear is part of the flywheel itself, not pressed on separately. Pressed-on ring gears can walk, slip, or shear off the flywheel body under sustained abuse. One-piece construction eliminates that failure point entirely and provides more uniform heat transfer across the friction surface.
• CNC Machined and Balanced to OE Specs
  Precision balanced for smooth operation at sustained high RPM. The S2000's F20C revs to 8,800+ RPM and the F22C to 7,800+. Any imbalance at those speeds creates vibration that you'll feel through the entire drivetrain. This flywheel is balanced to eliminate that.
• SFI 1.5 Certified
  Meets the safety standard required for sanctioned competition (SCCA, NASA, HPDE). If you're running track events, this checks the box.
• Resurfaceable
  When your clutch disc wears out, a machine shop can resurface the flywheel friction face instead of you buying a whole new unit. Over the life of the car, that saves you real money.

Important Notes for AP2 Owners (2004-2009)

If you have an AP2, you're making the biggest jump, going from a 21 lb stock flywheel to 11.5 lbs. Two things to know:

• Consider swapping to the AP1 slave cylinder. The AP2 has a clutch delay valve (CDV) built into the slave cylinder. Honda added it to smooth out engagement with the heavier AP2 flywheel and protect the drivetrain from shock loading. With a lighter flywheel, the CDV can make the clutch feel vague and cause slippage during fast shifts. Most AP2 owners running aftermarket flywheels swap to the AP1 slave cylinder (Honda part 46930-S2A-003), which eliminates the CDV and gives you a more direct, mechanical clutch pedal feel. It's a direct bolt-on swap.
• It's not mandatory though. Some AP2 owners run this flywheel with the stock CDV and are perfectly happy, especially if they're not doing hard track shifts. If your car is mostly street-driven, you can always try it with the stock slave first and swap later if you want more pedal directness.

Clutch Compatibility

This flywheel works with every stock and aftermarket clutch assembly for the S2000. Competition Clutch specifically recommends the ST for their Gravity, Stage 1, and Stage 2 clutch kits. The most common S2000 setups in the community pair it with:

• OEM Honda pressure plate + OEM friction disc (proven, reliable, great for street)
• ACT heavy-duty pressure plate + OEM disc (increased clamping force without changing pedal feel much)
• Competition Clutch Stage 1 or Stage 2 kits (matched to this flywheel weight)
• Exedy Stage 1 kits (popular combo for a reason: holds well, drives well)

If you're running a Stage 3 or higher clutch (6-puck, ceramic, etc.), you'll probably want to consider the ultra-light STU version instead. The combination of an aggressive clutch disc and a heavier flywheel can work, but the STU is a better match for that type of setup. Conversely, don't pair the ultra-light STU with a stock or mild clutch, that combo is harder to modulate in slow traffic and doesn't give you the benefit of the faster rev speed the STU is built for.

What to Expect After Install

The change from the AP2 flywheel is immediately noticeable. The engine revs faster, drops RPM quicker on upshifts, and responds to throttle inputs more directly. Heel-toe downshifting gets easier because the engine matches revs faster on blips. Most S2000 owners describe it as the car feeling "more alive" or "like how it should have come from the factory."

From the AP1 flywheel, the difference is more subtle but still there. You'll notice slightly faster rev response and a more connected feel. The bigger gain for AP1 owners is the SFI certification and the one-piece steel construction upgrade over the cast iron stock unit.

At 11.5 lbs, idle behavior stays close to stock. You may get very mild gear chatter that wasn't there before, but nothing like what you'd experience with a sub-9 lb flywheel. First gear takeoffs stay natural. Your passengers won't notice the swap. You will.

Vehicle Fitment

Part Number: 2-669-ST (Hybrid Racing SKU: COC-2-669-ST)
Weight: 11.5 lbs
Material: 4140 Forged Steel
Certification: SFI 1.5
Note: Does not include release bearing. Works with all stock and aftermarket S2000 clutch assemblies.

Who Should Buy This (And Who Shouldn't)

This flywheel is for you if: You daily drive your S2000, want sharper throttle response and better rev matching, run a stock or Stage 1/2 clutch, do occasional track days or HPDE events, and don't want to sacrifice street manners for track performance.

Look at the STU (9.25 lbs) instead if: Your car is a dedicated track build, you're running forced induction, you have a Stage 3+ clutch, or you don't care about daily drivability and want maximum rev speed between shifts.

You might not need an aftermarket flywheel at all if: You have an AP1 and you're happy with how the car drives. The stock AP1 flywheel is already reasonably light at ~14 lbs. The biggest gains from this upgrade go to AP2 owners who are dropping 10+ lbs of rotating mass.