you have civic SI type R with the K20A engine and 6sp transmission? correct?
yes the clutch is adjustable.
- loosen the clutch pedal position switch(lower of the 2 switches) locknut and back off the clutch pedal position switch.
- loosen the clutch push-rod locknut and turn the push-rod in or out to get the desired height and stroke of the pedal.
- tighten the push-rod locknut
- with the clutch pedal released, turn the clutch pedal position switch in until it contacts the clutch pedal.
- turn the clutch pedal position switch in an additional 3/4 to 1 turn.
- tighten the clutch pedal position switch locknut.
- loosen the clutch interlock switch(the upper switch) locknut and then the interlock switch.
- press the clutch pedal to the floor.
- release the pedal about 1/2 in. from the fully depressed position, and hold it there. adjust the position of the interlock switch so that the engine will start with the clutch pedal in this position.
- tighten the interlock switch locknut.
clutch pedal stroke should be: 5.1 - 5.5 in
clutch pedal height should be: 7.76 in
if adjusting the clutch doesn't help with the transmission feeling notchy, may be the syncros.