Steelmesh....Just so you know...the adjustable master cylinder I purchased from Performance Autowerks does the same thing with regard to make the clutch engage more towards the top of the clutch pedal movement as opposed to the floor.
I have the slave spacer that came with the Spec Clutch kit (thinner than PAWs) and that coupled with the adjustable clutch master cylinder really does fix the issues with regard to engagement. It's just a matter of having it engage correctly as opposed to still putting that pressure on the plate when not engage or having the clutch drag because it doesn't fully separate when the clutch pedal is engaged.
I got the opportunity to talk to Centerforce clutches (they use to make a clutch for our car) about our slave cylinder since they make a long travel version of our slave cylinder. Without going into specifics (because frankly I can't remember them all and even trying to process them all made my head hurt) the slave cylinder's travel is very critical.
I took a stock Kappa Slave to have them look at it so we could see if it was similar to theirs (looks identical since their product is for GM applications) and to explain the difference. Looking at our slave they mentioned the throw was very short. Theirs was about three to four times the travel of our stock unit. They then went on to explain what each part of the system does.
The spacer behind the slave cylinder sets the bearing deeper into the clutch. Thus the slave now will push further in to fully disengage the clutch but will not travel back out as far to re-engage the clutch. The Slave must also account for clutch wear and thus still be able to come back out far enough as the clutch wears to maintain engagement. The overall distance the slave travels and the distance it is fully out are both critical.
The Master Cylinder is completely different. No matter how you adjust the master cylinder, it has NO affect on how far the slave travels or, if when at full extension, the clutch is completely disengaged. Only the travel (and depth) of the slave can determine that. The adjustable master cylinder only allows you to adjust WHERE in the pedal's travel the slave reaches full disengagement.
Needless to say it was a very enlightening conversation.
As for my 2.4 with the stage 3 clutch, I noticed there was an issue shifting from 2nd to 3rd during WOT "quick shifts" when I first installed the clutch with the spacer. Clutch engagement was right off the floor. It was so bad, I wound up breaking my trans. The molded aluminum guides in the trans that guided the shift lever internally physically broke from me trying to get it into gear. When the new trans went it, I got the adjustable master and had it set so that clutch engagement happened about half way through pedal travel and not right by the floor. My theory is that before, when I would try to quickly shift, I wasn't hitting the area of pedal travel that was where the clutch was fully disengaged and thus "ramming" the shift lever into the gears. With the adjustable master on the new trans, this problem is gone.
Thus with the adjustable master cylinder, I've set the point at which the slave fully disengages the clutch further from the floor so during high speed shifting moments, I'm quicker to get the clutch fully disengaged in the pedal's travel and not trying to change gears when the clutch is still partially engaged like before.
