We decided to remove our CDV, or clutch delay valve, today while installing our ClutchMasters FX400 6-puck Rigid Disc Clutch and decided to document it for anyone interested in doing this nifty little mod.
What does removing the CDV do? The engineers at Honda has been putting a CDV system on many of the recent platforms to reduce drivetrain shock. The CDV allows the clutch system to simulate "slip" in an attempt to save the transmission/drivetrain. However, for racers and enthusiasts looking for more of a raw driving experience in his or her car this can be annoying. Removing the CDV greatly improves clutch engagement which in turn improves 60fts and shift times. The other cool thing is this mod costs $0 aside from a new bottle of clutch fluid needed to bleed the clutch system.
The 10th Gen's CDV assembly is identical to the 9th Gen's, so this may look familiar to some.
The CDV is located in the slave cylinder which is attached on the front of the transmission. The slave sylinder can be removed by taking out the two 12mm bolts holding it on. Next you will need a 14mm and 10mm wrench to remove the clutch line from the slave cylinder. Now the slave cylinder assembly should be able to be completely removed.
Remove the C-Clip below the bleeder valve with a pick or very tiny flathead screwdriver. This step is the biggest PITA
Once this is out you can remove the white/black plastic CDV from the slave cylinder with the same pick/screw driver that you removed the C-Clip with.
Everything should look like this once removed.
Throw the CDV in the trash where it belongs and then carefully install the aluminum O-ringed cap back into the slave cylinder and fasten it into place with the C-Clip.
Install everything back together in the reverse order in which it was taken off. Bleed the clutch system and you are good to go!
Here are some supplemental pictures from our clutch install!
Stock Civic Si Clutch vs ClutchMasters FX400 6-Puck
Stock Civic Si Clutch Disc
ClutchMasters FX400 6-Puck
Stock Civic Si Dual Mass Flywheel