Hi guys,
I have a centerforce pressure plate, disc, and bearing installed on my car. I have modified the mechanical clutch linkage to work but, the pedal is extremely stiff (I guess it’s the high performance pressure plate.) After 20 min of driving my leg is so exhausted that I can’t move the car with out burning out. Will this problem be solved with a hydraulic clutch system?

I appreciate your input.

 

Is your motor so strong that you need the centerforce. You can get a high perf Ram that won't kill your, a lot let work than a hydraulic conversion

 

I just finished an LS1 and a Richmond 5 speed install and that was a lot of work. I alredy invested into the center force $$$ and taking the pressure plate out will be soooo much work. I researched the hydraulic clutch installation and it doesn’t seem that bad. I just need to know if hydraulic will give me significant assistance while pushing on the clutch peddle. I just want to finish it’s been 8 months since I started this project and I want to enjoy the car. the engine is great but shifting defiantly sucks.

 

I do not think it is the centerforce causing your problem. They should have about the same or perhaps a little more than stock pressure. I have the centerforce II myself. A hydaulic clutch may help a little...but not much.


I would check for a bind or linkage setup issue first. For example...
Do you happen to have a aftermarket lakewood fork? When I first dropped in my 5 speed with a hydraulic clutch it was very stiff and I could not stand it. I found that the lakewood fork was catching on the edge of the thrust bearing and not allowing it to pivot freely. When the fork moves into engagement position the bearing needs to be able to pivot in the fork. I had to grind some material from inside the fork...clutch pressure was then cut in half.

Also check that when your fork is disengaged it is far forward...almost touching the bellhousing. It needs to be in that position for the best leverage. If not...you need an adjustable clutch ball.

 

One very simple and often overseen reason might be a wrong throw-out bearing. Corvette clutches need to have a lower (thinner) bearing; I think it was 1,25 rather than 1,5" on other GM applications.

I the bearing is too high, the clutch linkage is positioned in a way, that you do not have maximum leverage when pressing the pedal.

Check the motorside lever of the Z-bar. The correct position is about 6 o'clock. With a too high bearing, the lever usually is somewhere around 8 o'clock. Locking at the lever, you will immediately see, how leverage is reduced with this wrong position.

Regards,
Thomas

 

carguy4sure, if you put in a hydraulic clutch, why do you still use a clutch fork? zamika, I put in a hydraulic clutch and it made the clutch world's better; smooth and consistent all the way through the stroke. It removed the archaic, notchy, mechanical feeling altogether. In my opinion, it is a mandatory modification regardless of the problem you are having. My clutch felt awful before the swap, compared to newer cars. Now it is modernized and much more enjoyable to shift gears. My advice is to order one from Keisler a.s.a.p., put it in and go from there. It will probably alleviate your problem altogether as it did mine.

 

Had hydraulic clutch on a BMW...hated it..real wimpy..

 

I agree, rihwoods. I had a few BMW's in my family as well. Their shifting and clutch are VERY wimpy. It felt like the shifter was going to fall off. I assure you that adding a hydraulic clutch to a C3 vette feels nothing like that.

 

Think they are a good idea for ATV's....for the girls...

 

Rihwoods, if you wish to drive an outdated, archaic car, be my guest. Gauging your manhood based on the financial inability to replace an outdated clutch is a strange method, yet I commend your audacity. There are others who wish to improve the performance of their cars and I belong in that group, however emasculating it may seem to you.

God bless you, rihwoods. It is people like you who allow superior products to be available to me, rather than be on back order!

 

zamika0a was asking for opinions..
As for me..I just happen to like the 11" non-slip clutch and Hurst set up on my 69..and the stock clutch on the 78...no problem in traffic or otherwise...zamikaOa could just have a component issue....????

 

There are two versions of hydraulic clutches. I have the slave cylinder mounted to the side of the bellhousing that operates the fork. The other version uses an hydraulic thrust bearing that does away with the fork completly(they are expensive but very nice).

Having been through the problem described in the original post and I feel very strongly that his problem is a bind or setup problem. Hydraulic clutches do not change pedal pressure much at all...but does make for a smoother feel.

In regards to all the comments about wimpy clutches 'because the BMW was that way'. I think that you are making a big assumption that the soft wimpy feel is because of the hydraulics. Leverage is what does that not the linkage type used. Keep in mind that almost every car out since the 1980's uses a hydraulic clutch... including C4-C6 corvettes, 80's Camaro's, Stangs...etc etc. I would not say that they had wimpy clutches. BMW'w were designed for a different market than us 'hot-rod performance types'.

So lets compare apples to apples. I had the opportunity to compare a well setup C3 Mechanical to C3 Hydraulic. The Pedal pressure on the hydraulic was slightly less and had a smoother feel. But on both the clutch engagement feel was the same. I like to be able to clearly feel where the clutch is. I personally like the hydraulic better only due to ease of installation and maintenance. Otherwise not much difference in them.

 

My hydraulic clutch kit has the hydraulic throwout bearing and the improvement is such that it is now much better than the outdated original equipment. God bless Keisler and I wish all C3 owners could enjoy the same improvement that I have.

 

How about some pics of your install ??? Pleeeeeze....

 

In regards to all the comments about wimpy clutches 'because the BMW was that way'. I think that you are making a big assumption that the soft wimpy feel is because of the hydraulics.[/QUOTE]

Maybe....and there are performance clutches that vary in torque capacity,too...

 

I have a DF Centerforce clutch on mine and it is about the same as the stock clutch with regard to how much force is nessessary to disengage it. I would also recommend installing a adjustable heim joint clutch rod kit like the one below. It takes any play out of the linkage and is very smooth, well worth installing. There is another rod that goes thru the firewall to the clutch pedal, I don't have a picture of that one.

 

Pure barbarism!

 

I have the exact same setup, (clutch, linkage). I would recommend the SD linkage over the stock linkage anyday.

 

Thank you guys for the great input, my problem dosen’t seem that bad now due to your great ideas . I will tackle it by going with the following members recommendations

First
Since I was installing an LS-1 I had to relocate the position of the Z-bar on the block. Honestly I didn’t pay much attention to what V8yankie mentioned above. I’ll check it out and make necessary adjustments if needed.


Second

Hmm, good point. Actually the fork is not almost touching the bell housing and I think I might need the adjustable clutch ball. I found two very different Clutch Fork Pivot ***** on summit MCL-16908 and LAK-15501 . Could you please help me select the proper size.

Third

Man, my setup looks like crap compared to the rod kit you have. I defiantly would like to get one if the Clutch Fork Pivot Ball works. Can you please direct me to where I can purchase this kit from? I googled it but came up with nothing of use.

Finally

I researched the hydraulic thrust bearing and it appears to be the easiest solution to my problem, that if it’s caused by a bind or linkage setup, where this system will assure the motion of the bearing along the axis of travel. No worries about leverage, linkage setup, or fork catching on the edge of the thrust bearing.

The $64,000 question is who supplies a system with a decent price?
I guess the only spec of concern is the input shaft diameter which is 1 1/8 in.

I appreciate everyone’s input and please let me know your thoughts on the above.

 

Hey Grutzy, great advice. You sound very confidant and pleased with the Keisler system. Can you please provide me with the part number/ order info? I e-mailed Keisler but I want to check if they recommend what you got. I don’t want to take risks with wrong part delivery

Thanks