Help With Stiff Clutch Needed

[Skyride]

Hello there,

My first post and I need some help. I did use search but didn't find anything I could use.

The car is 1991 R32 GTR.

My clutch pedal is very stiff. I have almost no clutch play - it grabs in a very close distance - feels like on/off switch. I am looking for the ways to make my clutch pedal more forgiving. What would be the suggestions?

Previous owner wasn't sure but told me that it's most likely Exedy (?) twin plate clutch. Any way to identify the clutch without dropping the tranny?

I downloaded the R32 GTR service manual and will try to trace and check the system for leaks and whatnot. I don't know what lines I have - nismo or oem, I am not sure if any other components are oem or replaced (master cylinder, operating cylinder, what fluid used, clutch booster oem or a/m? etc.) So additional question would be what to look for and how to identify the major oem or a/m components.

I would appreciate any help I can get.

[Hadouken]

Stiff clutches are the bomb.

1 easy way. Go to gym, do bulk squats.

Clutch pedal will feel like your bitch

[Skyride]

Stiff clutches are the bomb.

1 easy way. Go to gym, do bulk squats.

Clutch pedal will feel like your bitch

Solid advice. Appreciate it. As you may know gym results may take time to take effect. What would you suggest I do in meanwhile as far as clutch adjustments go?

[Ben C34]

Aside from bulking up one leg, you could bleed the clutch and see if that helps.

But one massive clutch leg looks cool, so do that.

[MrStabby]

AFAIK you can't tell whats in there without dropping the box. Unless maybe you can see through the clutch fork hole a bit?

Check you have vacuum at the clutch booster (works the same way as a brake booster). If you clutch in and start the motor you should feel it in the pedal.

For the take up point, there should be an adjustment at the pedal (i've never need to adjust mine, so have never checked it out myself). I have the NPC 250mm organic, and its like a factory clutch - super easy to use with 300kw. I dont think it would last long under abuse tho (clutch dumps).

[Skyride]

AFAIK you can't tell whats in there without dropping the box. Unless maybe you can see through the clutch fork hole a bit?

Check you have vacuum at the clutch booster (works the same way as a brake booster). If you clutch in and start the motor you should feel it in the pedal.

For the take up point, there should be an adjustment at the pedal (i've never need to adjust mine, so have never checked it out myself). I have the NPC 250mm organic, and its like a factory clutch - super easy to use with 300kw. I dont think it would last long under abuse tho (clutch dumps).

Thank you I will check the booster operation and will play with pedal settings. Hope it will make the difference.

I messaged the owner again and he checked the info with the guy who sold the car to him. So the clutch I have is Exedy stage 3 hyper single 6-pack clutch/flywheel combo. He also mentioned that I have oem lines and oem slave cylinder. Well, I will try to play with adjustments as you suggested (also thank you so much for everybody who pm'ed me!) and if adjustments won't work, I just will exchange the clutch for something more forgiving. This car will not see the track and sitting in the traffic with this clutch is unbearable...

As for one leg buff - I don't think my husband will appreciate this type of the body upgrades haha

[sweefu]

Do they R32 GTR run a 3/4" slave cylinder the same as RB25DET gearboxes?
You could try a bigger bore slave cylinder, Nismo make a 7/8" from memory.

[Skyride]

Do they R32 GTR run a 3/4" slave cylinder the same as RB25DET gearboxes?

You could try a bigger bore slave cylinder, Nismo make a 7/8" from memory.

To replace only slave won't give me anything since I still have oem upstream. But! If I replace the whole upstream with bigger bore master, slave and pipes diameter, then I can keep the clutch. The clutch is a quality piece (from my research today) and Id rather keep it. Also saves me the trouble dropping the tranny.

So, that being said, what would be the suggestions for master cylinder, lines and slave cylinder upgrades? What brand would you recommend? What maximum size of everything I can put there? I still am gonna check the system as you guys suggested above but I really thinking now to replace the whole shebam and be done with it. Thoughts?

Edited March 7, 2014 by Skyride

[Skyride]

One more question - anybody tried to run vacuum pump for booster? If yes, who makes them or may be what car I can take it from and it will work?

Edited March 7, 2014 by Skyride

[Ben C34]

Replacing the slave to a larger one as suggested improves the mechanical advantage and will make it easier to push the pedal.

It's science.

[Skyride]

Replacing the slave to a larger one as suggested improves the mechanical advantage and will make it easier to push the pedal.

It's science.

But I wonder if you keep the master and the lines the same size as before - where the volume will come from? Sorry, I am not very bright

Edited March 7, 2014 by Skyride

[Ben C34]

It's the ratio between the surface area of the master to the slave that makes it easier (or harder) to push.

Say if the master is half the area of the slave it's twice as easy to push than both being the same size.

You don't need to change lines to get the advantage.

The nismo slave is larger for this reason.

The vac pump on the booster wouldn't help.

[sweefu]

Yep, as above.
I changed from a 3/4" to 7/8" slave cylinder this week and it made a huge difference, clutch felt substantially lighter and it's much easier to use, especially in traffic.

[Ben C34]

You don't have to buy this one or believe me, but this page explains that it will be a benefit.

http://www.thenismoshop.com/Nismo-JDM-Clutch-Slave-Cylinder-30620-RS580--Nissan-Skyline-GT-R-RB-Engine_p_84.htmlhttp://www.thenismoshop.com/Nismo-JDM-Clutch-Slave-Cylinder-30620-RS580--Nissan-Skyline-GT-R-RB-Engine_p_84.html

Edited March 7, 2014 by superben

[Skyride]

You don't have to buy this one or believe me, but this page explains that it will be a benefit.

http://www.thenismoshop.com/Nismo-JDM-Clutch-Slave-Cylinder-30620-RS580--Nissan-Skyline-GT-R-RB-Engine_p_84.htmlhttp://www.thenismoshop.com/Nismo-JDM-Clutch-Slave-Cylinder-30620-RS580--Nissan-Skyline-GT-R-RB-Engine_p_84.html

Sorry, I didnt mean to upset you. I just trying to learn. I got what you said in your post above.

Back to books

[Ben C34]

I'm not upset! No need to be sorry

[Skyride]

I'm not upset! No need to be sorry

Then it's all good I probably end up buying the Nismo cylinder that you suggested.

[sweefu]

Are R32 GTR slave cylinders the same as RB25DET?

[niZmO_Man]

Push type are same, pull type aren't.

http://www.kudosmotorsports.com/catalog/nismo-clutch-slave-cylinder-nismo-big-bore-nissan-skyline-r32-gtr-091989-021993-gts4-r33-gts25t-gts4-r34-25gt4-p-85.html

[533 RYC]

The 7/8'' would be the go.

What setup is your 6 pucker? Ceramic or brass button? What type of center is it running?

This is a contributing factor to clutch engagement.

Is it a new clutch? How many k's has it done?

If its fairly newish, & the adjustment is good, maybe it could do with a MEDIUM/CONTROLLED launch or two to change the friction point.

After my 500k run in on my NPC single organic (re-stickered Exedy GTR setup) clutch I performed 2 medium launches (my Stagea is FAIRLY stock) & it changed the feel & friction point.