PorSTi Project Thread…, Well that was fun, time to make some upgrades! Options

[Amenson]

The kit I got from KEP had a problem with the pressure plate. For 2 weeks, I thought it was my linkage or that ball pivot. But no, a spring was broken on the pressure plate. They sent me a new one.

I called KEP to ask about the travel required at the TOB to to disengage the clutch and they said about 3/16". He recommended 1/8" of slop at rest before the TOB touches the pressure plate. I am pretty sure that I am over that, maybe too far.

I measured some pictures of a clutch fork and it appears to be about a 2.6 motion ratio. If this is the case and I am stroking the fork ~1" on the outboard side, the TOB should be moving .38", almost perfect if I have the proper slop. If I am fully stroking the slave to the max 1.375" the TOB moves .53"...maybe far enough to crack a spring?

I need to measure the actual slave stroke and confirm the motion ration to know for sure. Does anybody have a clutch fork laying around to measure the dimensions from both ends to the center of the pivot cup.

I have been considering that the clutch disk could be rusted to the flywheel due to the obscenely long time that the project has been sitting. I mentioned this idea to KEP but they said that the disk I likely have is mostly organic and probably not the problem. I will still try to pop it free as a last resort before pulling the trans.

Cheers,
Scott

[GS Guy]

Scott,
Had my trans with installed clutch TO-arm and Kennedy TOB installed sitting in the basement and took some quick measurements. This is maximum throw of the arm, only limited by the physical opening in the bellhousing. Slave is not installed. My set-up also uses the 9" clutch/flywheel but just a stage II PP.

At the TOB face and outer slave pivot point I got:
TOB movement: 11/16" (0.6875)
Outer pivot movement: 1-5/8" (1.625)

1.625/0.6875 = 2.364 motion ratio

To get 3/16" movement at the TOB, should require 0.443" at the outer fork (slave) attachment pivot, less than 1/2"! My Wilwood slave has 1-5/16" total travel, waaay more than enough, at least on paper.

Hummm... I've got a 3/4" MC and the slave is also 3/4, easy 1:1. My Wilwood pedal ratio is 6:1 so that should be 2.66" of pedal movement for 3/16" at the TOB. That's good because I only have about 3" of total pedal travel available in my set-up!

Cheers,
Jeff

[Amenson]

At the TOB face and outer slave pivot point I got:
TOB movement: 11/16" (0.6875)
Outer pivot movement: 1-5/8" (1.625)

1.625/0.6875 = 2.364 motion ratio

To get 3/16" movement at the TOB, should require 0.443" at the outer fork (slave) attachment pivot, less than 1/2"! My Wilwood slave has 1-5/16" total travel, waaay more than enough, at least on paper.

Hummm... I've got a 3/4" MC and the slave is also 3/4, easy 1:1. My Wilwood pedal ratio is 6:1 so that should be 2.66" of pedal movement for 3/16" at the TOB. That's good because I only have about 3" of total pedal travel available in my set-up!

Jeff,
Thanks for the details, this is exactly what I needed.
I did a really quick measurement and my slave is moving 1", maybe a hair under. This makes my TOB displacement ~.42". Plenty of movement to release the clutch and should not be too much to have broken a spring. Sounds like your setup will work also.

So why isn't my damn clutch releasing? At this point I have convinced myself that the disk is stuck to the flywheel. Besides the rusty rotors the there has been no resistance on the drive wheels as it has only started in the air. I only started it in gear once or twice and it was in first and revere to see if the wheels would actually turn. From what I have found online, starting it in 5th and braking should free it.

I am leaving for a business trip this afternoon, so I will not get to try to "brake" it free this until Friday or Saturday. Maybe I can hop into it quickly at lunch and give it a try. (IMG:style_emoticons/default/happy11.gif)

Cheers
Scott

[Amenson]

The clutch works!!!

Started it up in 3rd with the clutch depressed, pressed the brake and the engine did not stall. No major shaking or thunking noises. Let the clutch out and the wheels started turning, pushed it back in and the wheels stopped. It even goes into gear with the engine running (IMG:style_emoticons/default/aktion035.gif) Wish that I would have tried this on Sunday.

Should be driving it out of the garage this weekend (IMG:style_emoticons/default/driving.gif)

Cheers
Scott

[ruby914]

Cool, I was just digging up the old posting about my clutch troubles for you.
Looks like you will not need them.
You're going to love your new toy. (IMG:style_emoticons/default/piratenanner.gif)
BTW, the car sounds great.

[Amenson]

Cool, I was just digging up the old posting about my clutch troubles for you.
Looks like you will not need them.
You're going to love your new toy. (IMG:style_emoticons/default/piratenanner.gif)
BTW, the car sounds great.

Hey Mike...mind finding that info about your clutch dilemma.

I put the car on the ground and it will not go in to gear with the engine running. I shortened the slave cylinder to make sure that I could adjust it properly and still could not get the clutch to fully release.

It will release enough that I can sit on the ground in gear w/o stalling the car but it will not go into gear. With the tires off of the ground they will slowly turn when in gear and the clutch pushed in. If I start the car in gear I can get it to move in that gear by releasing the clutch but if I want to select another gear I have to shut off the engine. I did get it out of the garage under power using this method but it was not glorious, it was rather infuriating.

Something is dragging in the clutch. I guess that I will have to pull the trans to figure out what.

[Amenson]

I was out of ideas so I pulled the trans. Actually came out relatively easily.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718773.1.jpg)

The pressure plate appeared to be properly in place and all of the bolts tight.
The disk looks basically new:
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718773.2.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718773.3.jpg)

The flywheel looks unused except one area is starting to show some heat spots.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718774.4.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718774.5.jpg)

The pressure plate is the same with a matching area showing some heat spots.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718774.6.jpg)
(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393718774.7.jpg)

I have no idea what these parts should look like at this point in their life but it is odd that there are asymmetric marks in the same region of both the flywheel and pressure plate. Seems like those areas could be rubbing even with the clutch in. Nowhere else does it show any signs of slipping.

Any thoughts?

Cheers,
Scott

[rnellums]

I know on the subie flywheels you can over tighten and cause dragging. Do you have a torque spec for the pressure plate bolts? I think it is around 14 ft - lb for the subie pp.

[jaxdream]

Do you need the spacer washers behind the cluch release bearing fork piviot ball if the flywheel has been turned ???

Jack

[ruby914]

Here you go Scott.

From my Narp thread:
Posted: Sep 21 2009, 09:39 AM

I got the stage II, 9" Porsche heavy duty pressure plate and clutch from KEP but the clutch is not fully engaging.
It's adjusted so tight that it bottoms out on the transaxle case. KEP tells me, I may need to place a washer under the little Teflon pivot on the clutch arm, or bend the arm. Wish I knew before I installed the motor.
Is this normal?

Sep 25 2009, 11:23 AM

I found the thread: Suby conversion and hydraulic clutch?, Two mods at once??
GS guy said:
"While studying the Kennedy installation instructions, it states specifically to:
1) Remove the sealing washer behind the ball stud where the clutch arm pivots -
apparently to reposition the clutch arm slightly and allow more lever travel?"
I don't know if I ever got installation instructions, not to say they didn't send them but I don't find any in my file.
I don't remember a sealing washer behind the ball stud, in my case I think I need to go the other way and add the washer behind the cup.
Looks like it will come apart soon, maybe I will just bend the arm?

Nov. 5
I pulled the transaxle back from the motor to remove the clutch pivot arm, shim the pivot cup and bend the arm.
The clutch still did not fully disengage. Pulled the motor and checked everything in relation to the stock motor and transaxle. Everything looked good.
Called the good people at KEP more than one time.. Finally found the problem. The diaphragm was cracked from between two fingers to the outer edge.
KEP mailed out a new one that day. I was told, with the newer kits you don't have to remove the washer from under the pivot ball.

And that was it.
Problem is, from your photo yours looks ok.

The diaphragm was cracked behind the rivet in the photo.

[Amenson]

Thanks for the feedback.

I know on the subie flywheels you can over tighten and cause dragging. Do you have a torque spec for the pressure plate bolts? I think it is around 14 ft - lb for the subie pp.

I could not find the instructions for the pressure plate assembly so I am not sure what the spec was. I am generally careful about torque specs for critical components so I would assume that they were properly torqued. Although anything is possible?

Do you need the spacer washers behind the cluch release bearing fork piviot ball if the flywheel has been turned ???

Jack

All of the parts are new.

And that was it.
Problem is, from your photo yours looks ok.

The diaphragm was cracked behind the rivet in the photo.

I checked again, very carefully, for cracks and could not find anything that even hinted of a crack.

I also measured from the pressure plate face to the flywheel mounting face and it was consistent.

What I did notice, and I have no idea if it is actually an issue, is that when I set the pressure plate finger side down, the pressure plate face does not sit level.

(IMG:http://www.914world.com/bbs2/uploads_offsite/www.digitaldash.org-4154-1393770861.1.jpg)

The level is zero'd to the measurement surface (otherwise known as my glass cooktop).

Is this a problem? It is the only thing that I can find that even hints at an issue.
I sent an email to KEP with all of my observations. They were helpful when I called last week. Hopefully they can give me some feedback to get me moving forward again.

Cheers,
Scott

[Amenson]

The feedback from KEP is that the the pressure plate likely has some issue.
I have a new on on the way and the old one is going back to KEP for inspection.

If all goes as planned I will have the car back together and working on Saturday as my from me to me birthday present and, more importantly, in time for our annual Chili Cook-off party where a whole bunch of people will be at the house who have been asking me for a long long time when the car will be running. (IMG:style_emoticons/default/poke.gif)
Hopefully I will never have to be asked that question again.

Cheers,
Scott

[76-914]

Happy birthday. I'll be celebrating with you.

[Amenson]

Happy birthday. I'll be celebrating with you.

The tracking number says that my new pressure plate will arrive tomorrow.(IMG:style_emoticons/default/cheer.gif)
Here is my excellent schedule through the end of the weekend.

Now...Continue to work like a dog to put the finishing touches an a work project that started 3 years ago.
6pm- Clean the flywheel and organize the tools/fasteners required to get the PorSTI back together.

Tomorrow:
7-9am final review/cleanup of work Documents.
9am-12pm Meeting to release project to production.
10am; UPS should arrive with pressure plate.
12:01pm Drive home and open Hopslam. (IMG:style_emoticons/default/beer.gif)
12:30pm-end: Install and test clutch. Drink more beer. (IMG:style_emoticons/default/beer.gif)

Saturday:
Morning: clean up garage for party. Pick up beer bottles from Friday.
11am-2pm: Brunch and beers at favorite restaurant. (IMG:style_emoticons/default/beer.gif)
2pm-5pm: Get ready for Party.
5pm-end: Party. (IMG:style_emoticons/default/beer.gif) (IMG:style_emoticons/default/barf.gif) Maybe do a burnout to prove to friends that PorSTI really is working. (IMG:style_emoticons/default/aktion035.gif)

Sunday:
Pick up more beer bottles.

[Amenson]

My plan was going great until the UPS guy showed up at work and did not have my pressure plate. Called KEP and apparently they are incapable of differentiating between a shipping and billing address. (IMG:style_emoticons/default/chair.gif) (IMG:style_emoticons/default/ar15.gif)

The pressure plate will arrive today but instead of installing it this afternoon during the half day of vacation I took for the purpose, I will install it tonight.

[Amenson]

Bad news, new pressure plate, same problem. (IMG:style_emoticons/default/headbang.gif)

This must be a stroke issue. What else could it be? (IMG:style_emoticons/default/confused24.gif)

[ruby914]

How's the beer? (IMG:style_emoticons/default/beer3.gif)

[Amenson]

How's the beer? (IMG:style_emoticons/default/beer3.gif)

Beer was great. Had a Hopslam, New Belgium Rampant, and NB 1554 while waiting for the pressure plat to arrive. Nothing like a couple of Imperial IPA's to take the edge off. (IMG:style_emoticons/default/drunk.gif)

Hopefully I can get some more travel out of my clutch pedal to confirm if more TOB travel will fix my issues.

[Amenson]

Not quite in time for for my party yesterday but....


https://www.youtube.com/watch?v=MIKFcDL4-NA


Time to take the wife for a ride around the block!

I will document what I did to fix the clutch issue later today!

Cheers,
Scott

[ruby914]

(IMG:style_emoticons/default/aktion035.gif)
Cool!
Now, take some time to drive it before you put it back on the jack stands.
(IMG:style_emoticons/default/driving.gif) (IMG:style_emoticons/default/biggrin.gif)