Competition Clutch Light Steel Flywheel for K20A2/A3/Z1/Z3

Competition Clutch Light Steel Flywheel (K20A2/A3/Z1/Z3)

If you want your K-series to rev like it’s supposed to, a lighter flywheel is non-negotiable. This Competition Clutch Light Steel Flywheel (K20A2/A3/Z1/Z3) is a direct bolt-on for any 2002–2006 Acura RSX Base or Type-S and 2002–2011 Honda Civic Si and is one of the cleanest ways to wake the car up without hurting street manners.

Why it actually works

• Real weight savings: This K20 light steel flywheel weighs just 11 lbs, dropping roughly 40% of the rotational mass compared to a stock O.E. spec flywheel K20. Your K20 doesn’t have to work as hard to spin it, so it revs quicker, blips faster on downshifts, and feels more eager everywhere in the powerband.
• Steel you can beat on: It uses a one-piece 4140 forged steel construction, so you get a strong friction surface that holds up under repeated hard launches and high-heat track use better than most aluminum setups with steel inserts.
• Street manners intact: The ST (Street) profile keeps enough flywheel mass to maintain idle quality and low-speed torque. You still get the sharper response you want from a light steel flywheel Honda or Acura guys like, but without the constant chatter and stall-happy behavior you’ll see from ultra-light race-only pieces.
• Clutch-friendly setup: The friction surface works great with Gravity, Stage 1 clutch flywheel combos, and Stage 2 clutch flywheel setups, so engagement stays consistent and you’re not chewing through discs every season.
• Bolts on like stock: Uses the OEM ring gear location, so this flywheel for Acura RSX or flywheel for Honda Civic Si doesn’t need shims, spacers, or weird hardware. Bolt it up, torque to spec, and go drive.

Specs

• Engine / chassis compatibility: Competition Clutch flywheel K20A2, Competition Clutch flywheel K20A3, Competition Clutch flywheel K20Z1, Competition Clutch flywheel K20Z3 (see full chassis fitment below)
• Material: One-piece 4140 forged steel, precision balanced
• Weight: 11 lbs (≈ 5.0 kg)
• Surface finish: Blanchard-ground, ready to install
• Cert: SFI 1.5
• SKU: COC-2-800ST

Fitment

• Acura RSX Base (2002–2006) – Acura RSX Base flywheel replacement
• Acura RSX Type-S (2002–2006) – Acura RSX Type-S flywheel upgrade
• Honda Civic Si EP3 (2002–2005) – Honda Civic Si flywheel
• Honda Civic Si FG/FA/FD (2006–2011) – light steel flywheel Acura / light steel flywheel Honda K20 application

If you’re building a responsive street car, a track toy, or a dual-duty K car, this Competition Clutch flywheel K20 setup is a solid middle ground: way quicker to rev than stock, far tougher than most aluminum options, and still perfectly livable in traffic. We run this exact style of flywheel on our own K-swapped cars for that reason.