Exedy Stage 2 Thin-Disc Clutch Kit 08905 - RSX-S, Civic Si

Exedy Stage 2 Cerametallic Thin-Disc Clutch Kit for K-Series - Part #08905

This is the track version of the K-series Stage 2. Same high-clamp cover as the 08951, but the cerametallic disc is roughly half stock thickness, which cuts input-shaft inertia enough that the K-series synchros stop fighting fast shifts. Exedy recommends the thin disc for circuit use, and that's how to buy it: a race clutch for an RSX-S or Si that lives at the track. For the street version, look at 08951 or 08951P4.

What It Is and Why It Works

Shift speed on a K-series is limited by how quickly the synchro can match the input shaft to the next gear, and that depends on how much the clutch disc weighs. The thin disc drops that mass hard. Shifts get faster, synchro wear goes down, and the clutch releases cleaner at high rpm. What you give up is heat capacity: less material on the pucks means it glazes sooner if it gets slipped in traffic.

The cover is ductile iron with about 40 percent more clamp than the Honda plate, and the disc keeps a sprung hub so the gearset isn't eating raw shock. It's the same 215mm, 24-spline family as the rest of Exedy's K-series Stage 2 line.

Specs

Fitment

What to Know Before You Buy

Flywheel surface has to be fresh. Thin discs are less forgiving of a wavy face than thick ones; chatter on a new install is almost always the flywheel.

Bed it in for 500 street miles before you race it. Cerametallic launched cold never holds rated torque.

Budget for a spare disc. The thin disc is a consumable on a track car and it's the reason Exedy sells the discs separately.