clutch issue - thoughts?

[minivan_don]

so the rb25 swap has been up and running like a champ for about a month now... but 1 issue is still here.

setup:- new fidanza rb20 flywheel- new stage 4 south bend dxd clutch (rated at 560tq)- rb25 slave (original)- new clutch master cylinder- new fluid (a few times)- removed stock dampener thing- ss line- 2.5 L motul 75w90, 1 L mt90- C's ss

Situation:- when under wot pulls and/or above 5000 rpms, i push the clutch in and its not only a bit hard/delayed to pull it out of gear but i either grind or get blocked out of going into the next gear. this happens in any gear. one time i hit the rev cut, i pushed the clutch pedal - which hit the floor with no pressure - and the clutch was still engaged!

ive changed the clutch master, bled the system a couple of times now, removed the stock pedal dampener, maxed out the free play... a couple people have thought it was my trany fluid, but i think things are pointing towards the clutch not fully disengaging.

this is peventing me from finding out what my car can fully do at the 1/4 mile track....

-DISCUSS

[Shocker]

try running a hard line from your clutch master to the slave. Get rid of the one bleeder. Just leave use the bleeder on the slave cylinder. Seems like you might have air in your lines not allowing the fork to completely dissengage your clutch.

Also play with the pedal some more if that doesn't work. I know I had mine too far adjusted out. On the dyno it wouldn't hold anymore than 120 hp. Brought it back to the fire wall about 1/2 and inch and it held the power fine.

[minivan_don]

mmm i dont think going from a ss line to a hard line will solve things.

we've changed out the fluid 2-3 times now and bled the **** out of it... there shouldnt be any air in the system.

i had this problem with my NA Ka as well but my buddy is using my old trany in his 350hp ka-t and its fine...

this is what keeps stumping myself and my shop. everytime someone mentions something we can almost rule it out cause we've tried alot already :S

[S12_hybrid]

My friend had an issue with his SR and an ACT clutch. His slave cylinder kept popping out. To fix the issue we machined (Just spun a piece of steel rod in the drill press and lathed it) a new slave to fork pin which was about 6mm longer than the old one.. It did the trick.

Also, check that your clutch pedal clevis pin is not worn out and that the pedal is solid and doesnt wobble.

-Dan

[minivan_don]

good call ... ill put the car up on the hoist and check to see if the fork is being moved enough

[ACTman]

Keep in mind that the Stage 4 Southbend disc has a full surface metallic on one side (according to the website) which makes for a heavy disc which adds a lot of inertia so it is harder on syncros when trying to shift fast. Try to adjust for better disengagement at the pedal (air gap), but don't expect super quick shifts running that particular design.

[TheOne]

i'd try checking the pedal where it connects to the master, since you got a new 1 it might be a lil out of spec(happened to me), also what brand is the new master cylinder?

[minivan_don]

we tried playing with the free play at the pedal on both the newer oem and a lorcdo replacement ...