As you may know, I have an LPE 427 with their mid cam and full exhaust, making over 500 rwhp. 21st CMC also put in an RPS Stage 3 clutch supposedly good for 600 hp. I'm keeping my fluids very clean, but I'm still getting a sticking clutch pedal. Today, it stuck at the very first high rev shiftafter driving it very mildly in traffic for less than 1/2 hr. This is after I purged the fluids out of the reservoir twice the day before. It was a little darker than usual but far from black. I'm wondering if a different clutch might help. I need to do something different, since just keeping the fliud clean is not working! Am thinking of the Textralia OZ700AB, their best unit. Your thoughts on this choice?

 

I had the same problem on my old SS. I replaced it with a Centreforce Dual Friction clutch and the problem went completely away AND I got a great clutch feel to boot (heavy..... but I like a heavy clutch).

I tried everything on that SS to fix the problem (2 slaves, a new master, drill mod, bleeding 8 ways to Sunday, and more) and nothing helped it.

I have mentioned this solution in other threads and got flamed for it. Take this advice as you wish, but it worked for me.

 

I would go with the Textralia OZ700, i have heard way to many bad stories on SPec clutches. Good luck.

 

I'm going to ask a few guys that install these things day in, day out, and see what they say too. I did have a centerforce dual friction in my 99 LPE, and also in my 91 LPE, so I'm familiar with those. Of course, this car's got a least another 100 hp over those cars.

 

I am installing mine soon, ill let you know how it goes.

 

Which clutch is that one? Ya, let me know. Are you having sticking problems too?

 

My friend GTODOUG has the OZ clutch and is having terrible sticking pedal problems. He's borrowed my MityVac to bleed, I haven't heard results yet. He's got similar HP to you and very similar problems. I'm sorry to say we haven't reached a solution just yet.

Here's the latest thread.

http://forums.corvetteforum.com/show....php?t=1752373

 

That shouldnt have anything to do with the clutch itself.

 

I should have been more clear. He's had pedal sticking problems with stock clutch & OZ clutch. Replaced slave 2 times and line and master once and has bled & turkey basted til he's blue the face. Last time he had a remote bleeder installed, tried bleeding that way, no luck, now he's going to use a MityVac to bleed it. Like Goodwood this problem is proving difficult to solve.

 

Boy, if that isn't me, I don't know what is!
Now I'm wondering if an expensive high temp resistant brand of clutch fluid might be worth trying before a clutch replacement?

 

yes.

 

ok, next question. Would I need to somehow drain all the oem fluid out 1st, or can I just start mixing the new stuff with the oem stuff via the extraction method til it's all new stuff? I don't have a remote bleeder and do have headers in the way. Also, what brand is a good one to try?

 

sure, good idea.

why would you wanna do that if your getting ready to take it apart?
you could try the ranger fluid replacement method, but extract as much as you can instead of refilling.
yep, headers will need to come off.
i, would look in the direction of the older, (last gen.) high-performance clutches, doesn't have to be corvette specific, .

too do it right, you should, replace all your clutch parts with upgrades.

when your done. fill it with some good high-performance track fluid, and imo, don't worry about changing it until the pedal becomes mush.

 

Steve I am the guy Joe G. is refering to. I am having the exact same issue. I have a remote bleeder installed as well. I have the OZ700 clutch you are contemplating getting. I had by buddy Robert come by the house last night and we bled the system again. The instructions we were given to bleed the system are the same ones that basically Ranger and others have given on the board as well.

Here is what we did:

1-Pumped clutch pedal 10-20 times
2-Opened bleeder
3-Slowly press clutch pedal to floor and hold it there
4-Fluid will come out of bleeder
5-Close bleeder
6-Check resivoir and fill if necessary
7-Pump clutch pedal until pedal feels normal(usually 3-4pumps to feel normal again, and continue pumping an additional 20 times or so)

We then repeated process until clutch fluid was crystal clear. My friend that came over did the exact same procedure on his 02 Z06 with the same clutch and hasn't had any issues. The only thing different we noticed during the entire process is that during step 3 when we pressed the clutch pedal to the floor, my pedal would stay on the floor even if I took my foot off. His pedal would return halfway if released.

I am going to drive the car this morning to see if the issue is resolved. I was thinking of replacing the clutch at this point as well. I would absolutely set the car on fire if I went with a heavy clutch thinking it would resolve this issue and it didn't. That would be the only thing that could make matters worse at this point.

I also heard that the heat issue might be the problem. I am willing to try anything, but if I'm paying to have the trans dropped again I want the issue resolved.

As I mentioned to Joe, I'm willing to pay anyone to resolve the issue at this point. It is so frustrating to have all this power on tap and not be able enjoy it.

By the way Steve, my setup is similar to yours.

LME built 403 w/AFR 225's
OZ700 clutch
AR 1 7/8" headers
Borla exhaust
Vararam/spacer
Fast 90mm

 

Boy, you're talking my language brudda! This is without a doubt, THE most frustrating mech issue I've ever faced in all the yrs I've had high hp cars. You're right, it really sucks to have all this hp, and not be able to drive it and enjoy it like we should, and paid SO much money to do!
Edit: btw Doug, I'd love to do a best 2 out of 3 head to head race with you @Moroso on street radials.(I'm running 295 KDW's). Wouldn't that be fun!!??

 

do you still have the return assist spring installed?
don't do that, , give it too me first. i could really enjoy two, much less, three. then again, four would be nice. and five, and so on and so forth.....
once you drop it, check out the case, see if you can find a cooling method, not too cool mind you.
which, i would take up with your tuner.

what did you ask him to do? did you ask to have mods installed or did you get one of those package deals?

what have you had done?

what does the engine dyno?

did they build it in the car?

match the clutch to the flywheel numbers. back filling the numbers from a chassis dyno doesn't work as well.

 

HUH? Clarify, I'm not understanding you on this one.


Oh, and Steve I wold love to take you up on your offer at Morosso. That would be funny. Two N/A vettes with 500whp+ and 2-3 second delays between shifts. I can see the time slips now, lots of trap spee and no ET ability due to this stinking clutch issue:

11.98@128.5mph vs. 11.99@128.2mph.

I would be the faster car of course LOL

 

Doug, the reason Robert's pedal comes up and yours doesn't is the return spring. Robert pulled his years ago I'm 99.9% sure (we've got so many Vette buds down here I get confused). Pull your return spring out, it's not too hard once you look at it and figure how it works. I did mine at the track in a 30 seconds on my C5. The spring holds the clutch pedal down.

I can't promise it'll fix the problem....but it did work on my C5 the only time I had the sticking clutch problem. And it's free.

Did you try the MityVac with some pipe thread sealer on the bleeder? You were sucking air past the threads on the bleeder I'm sure...forgot to tell you about that. Sorry buddy! Speed bleeders come with thread sealant on them and you have to reapply it every so often depending upon use.

Goodwood, I use exclusively Motul 600 fluid in my clutch and I never have any problems. I have doubt that it'll fix your problem though, but again, cheap to try.

 

Doug - post up a pic of the fluid you pulled out using the baster method........

 

That's so funny, 'cause the one and only time I went to Moroso, I did a high 11 with a trap speed of 128! This was on bowling ball hard GS-c's and my stock 3.42 diff (have a 3.90 now). And ya, I shifted slow on purpose, and ya, the effing clutch stuck going into 4th on the very 1st run! Keep that challenge in mind for when I get back to FL in Oct! Maybe, just maybe by then, we'll ahve this crap sorted out. And Joe, I still haven't checked to see if my return spring is still there. Gonna do that today!