ls6rx7

The other day i was driving my LSX powered rx7 and i noticed that the clutch releases/slips but only at high rpms and in 3rd or fourth gear. Whats the cause for this?

I can fully push the gas to the floor in first and second with no slipping then i get into third (same with fourth) hard and it holds and pulls strong all the way to around 4500rpm then it is as if i pushed the clutch in as the motor suddenly revs from 4500 to redline fast enough that i usually can not get my foot off the gas fast enough to stop it from hitting the rev limiter. Also it doesn't always do it in one or both gears sometimes it holds strong.
When it does decide to slip I let off the gas as fast as possible and push the clutch in, it seams as if i have slightly more clutch pedal pressure then i normally do.

Its a T56
Im running a fidanza light weight flywheel and a spec stage 3 clutch.

Dabeztz28

iTrader: (27)

how old is that clutch

ls6rx7

Well im not 100% sure. It looked to have a decent amount of life left in it. I got it for free, used out of my buddies Z28 when he changed his trans.

Do you think its about out of life?
That thought had crossed my mind too but since it holds strong in 1st and 2nd i kinda dismissed that possibility.

jmm98LS1

iTrader: (28)

Is your clutch engagement really high?....like clear at the top of the pedal travel? Did you put a shim behind your slave cylinder?

ls6rx7

I did not shim it but my clutch engagement is almost as soon as the pedal leaves the floor. Although it is an after market master cylinder made by US brake, adapted to work with the rx7 and the T56, so the travel on it might not be the same as on an F body.

Honestly i didnt even think about shimming it since it has the fadanza light weight flywheel with replaceable face plate... I always thought that you only needed to shim it if you had the flywheel resurfaced. Isnt that true?

Ive even bled the system over and over thinking is was air in the line.

ls6rx7

It did it again (after working just fine for some time) but this time in 6th gear...
The other day it warmed up so i took my car out and did a quick run to about 130 and held it there for a sec. I got back on the gas in 6th and it was almost like i pulled it out of gear as it revved freely. I pushed in the clutch pedal to find it was a lot harder to push to the floor then usual. After the pedal reached the floor pedal pressure went back to normal and my clutch started grabbing like it should and has been working fine since.

Then the other day after a quick run though 1st-3rd the clutch felt soft and would catch almost as soon as the pedal came off the floor.

This problem is driving me nuts! Any suggestions?