Hybrid Racing 17-21 Civic Type R Clutch Master Cylinder Upgrade Part Number: HYB-CMC-01-15

The OE Nissin CMC used in the kit has an aluminum piston body compared to the plastic assembly in older models. The plastic assembly has the potential to deflect in racing conditions or by using a stronger pressure plate. We have also used the Nissin CMC in our cars and sponsored race programs for over five years.

In 2002, Honda introduced a damper and delay valve in the clutch hydraulic system for US models with K-series powertrains. The damper in the CMC body casting, identified by the external triangular section, reduces vibrations transmitted to the clutch pedal, minimizing cabin NVH and vehicle feedback.

We removed this damper to enhance the connection to the powertrain, resulting in increased pedal feedback at higher engine speeds and loads.

The delay valve, housed in the slave cylinder, works by slowing the engagement of the clutch. It does not affect the fluid flow rate into the slave cylinder, meaning it doesn’t impact clutch disengagement. The valve employs a one-way valve and bypass orifice to achieve this effect, creating back pressure against the clutch fork and reducing its acceleration and velocity during clutch engagement. This delay valve produces consistent shifts during spirited driving, although it increases the time the clutch slips compared to a non-valved slave cylinder. 

However, no evidence suggests that the delay valve in the slave cylinder accelerates clutch wear or significantly impacts performance. Determining its specific impact on lap times is challenging due to numerous contributing variables. Upgrading to our CMC kit will improve the pedal feel, however, it can make the entire system slightly more noisy under normal conditions.