Alright, I've been reading everything I can find, searching the forums, checking manufacturers websites - still having trouble picking a clutch/pressure plate for my 4-speed conversion.
My requirements are, in order of priority:
1. Around $300 (or less)
2. NO heaver pedal (or lighter) than stock
3. Handle up to 400 HP

I have a RAM (semi) metalic clutch in another vehicle and it has a lighter pedal than the stock 4-cylnder set-up I removed (www.V8Ranger.com). It's a little bit difficult to 'feather', kind of on-off, but it's still actually easy to drive in that light vehicle. I looking for something that easier to slip for the daily driver that my Corvette is. With new clutch technology this should be easy, right?

 

I'm running a Center Force clutch and pressure plate in my car behind a 454 and like the feel of it very much. It's just a regular style clutch nothing special and not the high performance dual friction type.
It has reasonable pedal pressure and the only clutch I ever owned that doesn't have some chatter when engaging.
My biggest disappointment with it is it gave my engine a bad vibration right at 2000 RPM. That may not be the case with all of them but it is with mine. At 1800 or 2200 RPM the vibration is gone.
Wish I would have had it balanced before I installed it or just returned it for another one soon as I discovered it.
But I didn't want to R & R everything again so now I just live with it and try to keep it above or below 2000.

If you have a RAM clutch in your other vehicle like it, maybe you should stick with what works even if it is difficult to feather.
On the bright side maybe both clutches will work the same and there won't any learning curve when switching from one vehicle to the other.

 

I like the dual friction centerforce I have in my 69

I ran it behind a 800hp 540, and now behind a 600hp 427

Easy pedal and grabs real nice

Not sure your application but this is one example from summit

http://www.summitracing.com/parts/CTF-DF735552/

P.S. you get what you pay for in my opinion this is the best bang for the buck

 

qtlow

are you sure that vibration is in your clutch?

Might be in your flywheel.

Had a friend with a camaro and a 350 4 speed that had a bad vib around that rpm and after we pulled and rebuilt the motor we ground and balanced the flywheel and no more vibration

Just a thought

 

Hays 85-110 diaphram in my conversion, 11 inch, 6500 rpm, does not stick to floor.
Very satisfied

 

Hi Fonz, unfortunately yes, I'm sure the vibration is in the pressure plate.
When I built the motor I had the entire rotating assembly balanced including the flywheel and a monster 3 finger pressure plate.
The motor was smooth as silk through the entire RPM range but I couldn't tolerate the pedal pressure of the clutch anymore so I changed it out for the Center Force and that's when the vibration appeared.
The only other thing I did different at the time was change the pilot bushing for a bearing.

But to the original poster of this thread, don't get me wrong I love the Center Force. They build a good product and like Fonz said probably the best bang for the buck. I just happen to get one with a slight imperfection.
Next time the transmission comes out for whatever reason I have that pressure plate balanced and all should be good.

P.S. When I say the clutch has a bad vibration I don't mean mirror shaking, dash rattling vibration. It's just enough to feel and to me that's just enough to consider bad.

 

Stick with a diaphragm style pressure plate as opposed to a lever style. The diaphragm style has 18 little fingers on the pressure plate where the lever style uses 3 finger. Diaphragm style is light pedal effort.

Pick a disc based on torque output, not horsepower. Most entry level discs, like our SF Organix ( http://www.americanpowertrain.com/Clutches.html ) is strong enough to handle the power you stated, yet very "street friendly" and will not chatter. It also meets your 1st criteria and beats that by about $60.


Richard

 

I have a Hays clutch assembly in my Vette -- about 400 hp at the flywheel from a 383. Been there for years with no problems. Clutch pedal effort is fine.

Not to highjack the thread, but will anyway. Qtlow -- do you also have a vibration at 1,000 rpm? I put a Centerforce in my Camaro and there is a vibration at 2K. But there is also a vibration at 1K, and I'm thinkiing the 2K vibration is a harmonic. 3K seems ok and I haven't really tried it at 4K.

 

Nope, my vibration is at 2000 RPM only. Doesn't matter if I'm accelerating or decelerating either.
The entire RPM range above and below are just fine.
The vibration is in such a small window too. I just speed up 200 RPM or slow down 200 RPM and it's completely gone.
I've often wondered if the centrifugal weights on the diaphragm were the culprit but I seriously doubt it.
If they were I'm sure there would be way more complaints about them and they wouldn't be as popular as they are.

 

"Stick with a diaphragm style pressure plate as opposed to a lever style. The diaphragm style has 18 little fingers on the pressure plate where the lever style uses 3 finger. Diaphragm style is light pedal effort.

Pick a disc based on torque output, not horsepower. Most entry level discs, like our SF Organix ( http://www.americanpowertrain.com/Clutches.html ) is strong enough to handle the power you stated, yet very "street friendly" and will not chatter. It also meets your 1st criteria and beats that by about $60."

My mom had a 72 (I think) with a 350hp 350 4-speed when I was 14 and I could barely push that clutch pedal. Don't know what kinda clutch it had, sure it was stock though.

Everything I've ever used used was a diaphragm type and they were all lighter than mom's vette.

Has anyone reading this forum done business with these folks? I like the looks of their products and the're website more directly address's my questions...

I may give them a try.

Carl

 

I've been using the stock AC-Delco clutch and pressure plate for years with no problems, somewhere between 300-400 horsepower.

 

qtlow,
I have the same vibration and I have the Centerforce Clutch. A simpler solution than pulling everything out again for me was to put a Fluidampr Harmonic Damper on the engine. The vibration is still there, but it's much less noticeable. It all depends on how much it bugs you I guess.

 

WOW! Is the real truth coming out in this thread about Center Force clutches?
Before I bought mine I never heard of any vibration complaints about them but apparently maybe they do have issues. I thought it was just mine.
Honestly, the vibration does bug me. Any excessive vibration in an engine isn't good especially one you can physically feel. I'm just grateful it's in that small window of the RPM range so I'm able to work around it.

Thanks for the tip on the fluid damper. I might consider that.

I am also running Moroso solid motor mounts so I know that's only amplifying the vibration.
Technically though, the fluid damper doesn't eliminate the source of the problem. It's only absorbing it.
I don't know what the fluid dampers cost but I know they aren't cheap. It may be cheaper to pull it out and try to have it balanced. If it can't be balanced maybe I should just replace it since it's already out.
I would hate to do that because other than the vibration it's the best clutch I ever owned.
If I did have to replace it I wouldn't know what to get.
I suppose my requirements would be:

1. Around $300 (or less)
2. NO heaver pedal (or lighter) than stock
3. Handle up to 400 HP


Wait a minute, I think we just went full circle.
I sincerely apologize V8 ranger for hijacking your thread.
Now I might be in the market for a clutch with the same requirements as you.
Sheesh, never thought just posting in the Corvette Forum would start a "While I'm at it" repair.
Thanks guys.
When I woke up this morning I was more or less satisfied with my Center Force.
Now I'm not sure.

 

im in pretty much the same spot you are, just 300ish hp instead.

how are the mcleod streetpros?

wish i could find an exact replacement to my current clutch/PP. its an old dana, and i cant find a single thing on dana clutches.

 

Hijack, no problem. Sometimes its helps keep the respondes and ideas coming...
I had a Centerforce in a Mustang years ago and it worked fine, no vibrations. But it was a pretty stiff pedal, had to change from cable to hydraulic. Used one of those Mcleod hydraulic throw out bearing setups, it worked good but I had to pull it apart and rebuild it at least once a year

Carl

 

v8ranger,
My apologies for going on a tangent about my Centerforce vibration issues. To make amends, I have an idea to try. Outside of the vibration of the Centerforce, I love the clutch. It handles my 450hp 383 with ease and the pedal is lighter than stock. I have the ball and socket stock clutch linkage too! This would be the perfect clutch for you. I would do a Centerforce again and I will share what I plan to do when I change it to make sure I am vibration free. I'm going to take my flywheel and new Centerforce clutch/pressure plate to the machine shop and assemble it and balance it as a unit. That way I know if there is a vibration, it won't be from my clutch/flywheel assembly.

 

There are a lot of complaints about Centerforce, probably a bunch on this forum.
I've owned a DF and a II and not a single problem.
After reading the complaints I was thinking about switching to another brand,
but I just went ahead and bought another DF.
My personal experience has been too good...
I really like the II for a 400ish HP/torque engine.

 

I never knew Mustangs used clutch cables. But don't know too much about Mustangs either.
I wonder if it could it be possible that Ford engineering combined with clutch cable geometry wasn't meant to work with anything heavier than a Ford engineered clutch?
It wouldn't surprise me. Seems like Ford always over engineered everything and could never keep it as simple as GM.


This is good advice. I would suggest this too simply because of the other comments in this thread about vibrating Center Force's so I guess it's not as uncommon as I initially thought.
If you do decide on the Center Force, I suggest you do like brando1118 said.
Other than the vibration I still do really like my Center Force.

Fonz69 and Steve439 seem to have good luck with there dual frictions right out of the box. Maybe there's better quality control with those but I doubt it.
I think the only difference between the Center Force II and dual friction is clutch disk but still using the same pressure plate. Maybe someone else knows for sure.

Good luck with whatever you choose and let us know how it works out.

 

I went with the Centerforce dual friction (diaphram pressure plate).
It is a little heavier pedal than I was hoping for, but ok.
It chatters just a little when first engaging.
Worst thing is, just as I push the pedal far enough to release the clutch it feels like something is going 'over center'. Not bad enough for the pedal to stick to the floor, but very annoying. It does this with or without the engine running. I have been adjusting the linkage so as not to push the pressure plate any further than necessary but it occurs right at the point of disengagement.

I have a mostly stock linkage, the push rods are aftermarket with heim joints, easy to adjust.

Any ideas?