quote Originally posted by Dennis LaGrua: I find this thread on clutch strength amusing... blah, blah, blah...

What happened Dennis? Got bored over by the Fiero List? No one pays attention to your stinky crap there anymore? Did everyone there wrote you off already?
So you felt you had to come here and make a name for yourself hey?

You have posted 105 times and I still have to see a constructive bull$hit free post.

But, knowing all the manure you spread on the lists over the years, I wouldn't expect anything less from you.

Do me a favor, will'ya? Just stay away from the good and interesting threads -K? Find yourself a loosers thread and post there all you want!

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Winston Ojeda
88 Formula LT1
Milwaukee, Wisconsin, USA
http://www.FieroLT1.com
Home of the Fiero LT1
wojeda@FieroLT1.com

While Dennis' post didn't really have any constructive value, neither did the next dozen or so saying "Go the hell away, Dennis".

Can we talk about clutches now?

Does anyone here have experience with a non-marcelled disk with spring hub, or a marcelled disk with solid hub? Which did you like better?

quote Originally posted by Will: Does anyone here have experience with a non-marcelled disk with spring hub, or a marcelled disk with solid hub? Which did you like better?

Hi Will,

Never heard of a marcelled disk. Can you explain what it is? The diffrence between the two?

Thanks!

Rob D.

Marcelle (which I may not be spelling correctly) is making the disk wavy. Viewed from within the plane of the disk, the edge of the disk would look like a sine curve. As the pressure plate pushes, it hits the high and low points first, and squishes the curve flat as it continues.

This makes the clutch engage much more gradually than it would if the disk were flat. Gradual engagement = easy modulation = good streetability.

Considering the only tranny failures I've heard about on V8 Fieros were due to clutch failures, I've got a fun idea for a "torture test."

Put in a QM setup with a Fast Burn 385 crate engine using the Hot Cam. That should be about 425HP, and a clutch that can hold up to it. Then, give it the "Tina Stress Test."

Let's see what fails first:
-The Engine?
-The Transmission?
-The Clutch?
-The rear tires!! (this gets my bet )

quote Originally posted by Formula88: Considering the only tranny failures I've heard about on V8 Fieros were due to clutch failures, I've got a fun idea for a "torture test." Put in a QM setup with a Fast Burn 385 crate engine using the Hot Cam. That should be about 425HP, and a clutch that can hold up to it. Then, give it the "Tina Stress Test."

Interesting choice. Mind if it's fuel injected??

Dave

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- Silver '88 GT 5-speed (1 of 139) w/cammed 3.4
- Black '88 GT 5-speed ZZ430TPI at Archie's
- '87 & '98 Corvette Coupes

quote Originally posted by Formula88: Considering the only tranny failures I've heard about on V8 Fieros were due to clutch failures, I've got a fun idea for a "torture test." Put in a QM setup with a Fast Burn 385 crate engine using the Hot Cam. That should be about 425HP, and a clutch that can hold up to it. Then, give it the "Tina Stress Test." Let's see what fails first: -The Engine? -The Transmission? -The Clutch? -The rear tires!! (this gets my bet )

I've pretty much done the test already, pulled a bunch of hole shots, some side stepping the clutch pedal at 5,000 rpm (just being stupid and showing off). Everything survived that day, but the next day, just slowly pulling away from a light, the left inboard CV Joint let loose. CV's appear to be the next weakest link. That was about 3 years ago, haven't had a CV failure since, but I don't drop clutch at 5 grand anymore either.

quote Originally posted by Will: Marcelle (which I may not be spelling correctly) is making the disk wavy. Viewed from within the plane of the disk, the edge of the disk would look like a sine curve. As the pressure plate pushes, it hits the high and low points first, and squishes the curve flat as it continues. This makes the clutch engage much more gradually than it would if the disk were flat. Gradual engagement = easy modulation = good streetability.

Hi Will,

Did some digging and cant' find anything on a Marcelle clutch disk. I did, however find out about the Marcel spring that is part of a clutch disk that is wavy as you described. It does what you said, allows the pressure plate to engage the clutch disk gradually. Is this what you were referring to?

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Modified 2.8 (Soon to be a 383 V8 )
2.5" Drop
11" Brakes
17" Revolutions
RCC Coilover Suspension

quote Originally posted by chester: Hi Will, Did some digging and cant' find anything on a Marcelle clutch disk. I did, however find out about the Marcel spring that is part of a clutch disk that is wavy as you described. It does what you said, allows the pressure plate to engage the clutch disk gradually. Is this what you were referring to?

Yeah, that's what I was talking about. In clutches, the metal structure of the disk is itself a Marcel spring.

Okay. Let's get technical about clutches. The formula for friction is F=uN where the Force = F, u = coeffecient of friction and N is the normal force or clamping force. Do you see area or diameter in there anywhere? Area has nothing to do with friction force generated. So the diameter of the clutch has nothing to do with it's holding capacity.

In order to make a small diameter clutch hold as well as a larger one you need to either increase u by having a better friction material or increase the clamping force, as in pressure plate pressure. So where does diameter come in? Heat dissapation. The larger the clutch friction area, the better it can take the heat of slipping. So what is better, small or large? Depends on how it is driven. If you like to slip the clutch a lot, better get a large diameter. If you want minimal clutch pedal effort, get a large diamter. Want to go real fast and quick shift, get a small diameter with a heavy pressure plate.

When I first got my Fiero it had a CF standard clutch on a built 2.8 (3.1). This was a pretty high hp 2.8 with NOS. The clutch slipped when the NOS kicked in. It was probably pushing close to 250 hp then. I was terribly disappointed to find out that the CF clutch was just a stock clutch with a name on it. So when my N* went in I went to the Quartermaster dual disk "show car" clutch with organic facings. This assembly uses a small machined flywheel that weighs about 3 lbs bolted to the stock flexplate. The 7 1/4" assembly weighs about 11 lbs. The engine revs fast. Super fast. It has never slipped. It has relatively high pedal pressure, but not much more than the CF did. It can be driven just like any stock clutch. The center disk rattles when the clutch is depressed and sounds like a bad throwout bearing, which it isn't. (QM said it would get quieter as it is driven. It has, but it is still loud.) It is expensive. It has been in the car since 1998 with a lot of miles on it.

I would not trade this clutch for anything else out there. Period!

I understand that Tilton and maybe Ram have similar clutches. Stay away from all metallic disks. You don't need them and they are hard on the tranny. Also stay away from dual disk small diameter clutches if you like to occasionally slip your foot off at high RPMs. The hubs aren't sprung. They don't like that. They also don't like to be slipped a lot. You can slip it once, but better wait about 15 minutes before you do it again. But I have absolutely NO problem in stop and go traffic. NONE!

What I am getting to is that there is NO perfect clutch. There are clutches that are better than others for your driving style. Understand that first, and how you plan to drive the car, then choose. There are people who would not like my setup. That's understandable, too.

Ben, I understand your reasoning for going with the tripple disk QM clutch, but that may be a case of more isn't better. Perhaps if you were trying to launch 4000 lbs, but the Fiero is light and the N* revs like crazy. The 3 disk is going to grab more agressively. Talk to QM and see if they really recommend the 3 disk pack vs the dual disk. Just trying to save you some trouble. I'm not running a monster N* yet, but someday I'll have the P&P heads and cams in it.

quote Originally posted by wcapman: Okay. Let's get technical about clutches. The formula for friction is F=uN where the Force = F, u = coeffecient of friction and N is the normal force or clamping force. Do you see area or diameter in there anywhere? Area has nothing to do with friction force generated. So the diameter of the clutch has nothing to do with it's holding capacity.

This would be true if you were sliding the pressure plate across the disk.
Diameter comes into play when talking about torque. An area element dA at radius R (yes, I'm a physicist ) will hold a Torque equal to Pressure*dA*u*R. Increasing R increases the torque it can hold. Integrating from inner edge to outer edge yields
Holding Torque == (Clamping Force)*u*(O.D.^2 - I.D.^2)

I agree with everything else, though.

quote Originally posted by wcapman: The center disk rattles when the clutch is depressed and sounds like a bad throwout bearing, which it isn't. (QM said it would get quieter as it is driven. It has, but it is still loud.)

There must be something a little different about our QM setups, I don't notice any rattleing from my floater plate. Maybe my ears are just shot???

While I'm not going to try to work all the equations related to clutch disks, I tend to agree with Will that surface area is an important factor. Aside from improved lining material, the two double faced 7.25" disks give you a larger surface area than any single disk you can put in there. A 3 disk set should help improve durability life (certainly torque loading is improved even further), but as you stated it would be wise to consult with QM to see if there are any issues of concern for street.

I'm facing the exact same question right now. Also concerned about the 3-disc's tranny-input-shaft side MOI. Really just want the mileage, and to try something that hasn't ever really been tested yet. I can always use the same assy with a 2-plate, it will just be an *expensive* expiriment (actually, not too expensive, new outter ring, and sticking one floater and one disc on a shelf, and I've got a 2-plate... hrm. may have to run a *through* comparison

In an exotic, 30k between clutches is an eternity. I belive F355's service life is ~15k?

Oh, you're right with the FuN But remenber where that F comes from in a rotational moment setting ;D)

Best!
Ben.

quote Originally posted by wcapman: Ben, I understand your reasoning for going with the tripple disk QM clutch, but that may be a case of more isn't better. Perhaps if you were trying to launch 4000 lbs, but the Fiero is light and the N* revs like crazy. The 3 disk is going to grab more agressively. Talk to QM and see if they really recommend the 3 disk pack vs the dual disk. Just trying to save you some trouble. I'm not running a monster N* yet, but someday I'll have the P&P heads and cams in it.

------------------

Ben Cannon
88 Formula, T-top, Metalic Red. (2:13.138 at Sears Point) "Every Man Dies, not every man really Lives"
88 Formula, Northstar, Silver, In-Progreess. -Mel Gibson, "Braveheart"

What Will is describing is correct. The F in the equation F= uN is actually referred to as the polar moment. Torque is applied through the centroid of the disk area and is a function of the moment arm. This simply means that to carry the torque a small diameter clutch must have a greater u and a higher N. But the N is spread over a smaller surface area and N= Fc/A. For a street clutch still boils down to surface area and heat disappation. Like I said, you can achieve the same polar moment in a large clutch with less clamping force, hence lower pedal effort. But by having a larger diameter you also have a larger clutch surface area, and then to achieve N you have to have a greater clamping force and you are back to the same pedal effort.

The multidisk arrangement achieves a lot of surface area in a small diameter to help with heat disapation.

As far as the noise in my clutch is concerned, maybe I DO have a bad throwout bearing. I've been listening with a stethoscope the last few weeks and it makes some noise even when not engaged. I've been going on what QM told me. Hmmm, when I change trannies some day to put in the Gleason I'll change throwouts and see if that makes a difference.

Just got some bad news on SPEC from my next-door neighbor, who is in my club and the mid-atlantic F-body club.

> -----Original Message-----
> From: RichJ (home) [mailto:rjohnston1@cox.rr.com]
> Sent: Monday, May 13, 2002 11:57 PM
> To: AMCC-DC Cruise Discussion List
> Subject: Re: Clutch manufacturers
>
>
> I'd stay away from SPEC myself. Too many people have had
> problems with them
> (both longevity and chattering). I helped a friend put a stage 3
> kevlar in
> his 95 Z28 last year. SPEC claimed that the clutch was good for up to 600
> hp or so no problem. 2,000 miles later we are replacing it (<400
> rwhp, mid
> 12-sec car on drag radials). SPEC now says that lots of people have had
> problems with the stage 3 kevlar and so they don't sell it anymore. They
> gave him a free replacement in a different material, but it's
> hardly trivial
> to change the clutch even in a Camaro, so the whole thing still is pretty
> unsatisfactory IMO.
>
> Personally, I have a McCleod street twin so I could install and forget. I
> don't need it for the amount of power I have, but at least I don't need to
> worry about it.
>
> Rich
> 95 Z28
> 98 M3
>

quote Originally posted by wcapman: As far as the noise in my clutch is concerned, maybe I DO have a bad throwout bearing. I've been listening with a stethoscope the last few weeks and it makes some noise even when not engaged. I've been going on what QM told me. Hmmm, when I change trannies some day to put in the Gleason I'll change throwouts and see if that makes a difference.

Could be it, the reason I say this is because the throwout bearing isn't that expensive so I throw a new one in each time I put new disks in (don't know if you've been doing that). There's also a very minor amount of metal removal that has to be done on the stock throw out bearing, don't know if you're aware of this.

quote Originally posted by crazyd: Um, what does the S in HSP stand for? Dave

h"S"p = "H"as "S"lipping "P"roblems

BTW, I just bought a complete QM assembly for my 69 project. Good folks to deal with. I am shooting for 600 h"S"p and gobbs of torque. They did NOT suggest the ultra exotic assembly, as the day to day streetability would be a issue. This was also based on the fact that I told them the car would see once in a while track time, and mostly street cruising.

quote Originally posted by crazyd: Just got some bad news on SPEC from my next-door neighbor, who is in my club and the mid-atlantic F-body club. > -----Original Message----- > From: RichJ (home) [mailto:rjohnston1@cox.rr.com] > Sent: Monday, May 13, 2002 11:57 PM > To: AMCC-DC Cruise Discussion List > Subject: Re: Clutch manufacturers > > > I'd stay away from SPEC myself. Too many people have had > problems with them > (both longevity and chattering). I helped a friend put a stage 3 > kevlar in > his 95 Z28 last year. SPEC claimed that the clutch was good for up to 600 > hp or so no problem. 2,000 miles later we are replacing it (<400 > rwhp, mid > 12-sec car on drag radials). SPEC now says that lots of people have had > problems with the stage 3 kevlar and so they don't sell it anymore. They > gave him a free replacement in a different material, but it's > hardly trivial > to change the clutch even in a Camaro, so the whole thing still is pretty > unsatisfactory IMO. > > Personally, I have a McCleod street twin so I could install and forget. I > don't need it for the amount of power I have, but at least I don't need to > worry about it. > > Rich > 95 Z28 > 98 M3 >

Well, I'm still going with it. Call me a pioneer, gunie pig, lab rat whatever. I already made it clear to them that if this fails, they might as well drop their Fiero line cause thier name will be MUD.

Rob D.

quote Originally posted by chester: Well, I'm still going with it. Call me a pioneer, gunie pig, lab rat whatever. I already made it clear to them that if this fails, they might as well drop their Fiero line cause thier name will be MUD. Rob D.

hehe.....there you go, my kinda man.

I wasn't gonna comment but I also got post 100 with this one.

Archie

*just keeping things up top*

Excellent thread!

This thread was making me have doubts about the smallblock chevy swap... But then I snapped out of it and sent Archie a money order for my sbc kit.

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quote Originally posted by GT Bastard: This thread was making me have doubts about the smallblock chevy swap... But then I snapped out of it and sent Archie a money order for my sbc kit.

I have NO doubt that when I'm done I'll have on hell of a pocket rocket! Elvira got me a cute decal for the rear view mirror. It goes along the lines of what's printed on the side view mirror "Vehicles may be closer then they appear" only it reads "Objects in mirror are loosing" hehehehe

Rob D.

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Modified 2.8 (Soon to be a 383 V8 )
2.5" Drop
11" Brakes
17" Revolutions
RCC Coilover Suspension

quote Originally posted by chester: Just look for the guy in the Intrepid No Fiero for me this time.

Don't feel too bad, I won't have mine done for the Dells, gonna have to run my stock hood (which means no paint job, and my old front bumper cover)

this has been a good thread, I get a little slippage in 2nd when I'm hard on the gas.

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Ok, clutch arrived as promised. That's always a good start

Here are the pic's;

So there you have it. I will bring it with me to Carlisle for those of you that would like to examine it in person.

Rob D.

[This message has been edited by chester (edited 05-16-2002).]

Huh...doesn't look like there's much to it!
Since I got a standard dual friction Centerforce, I'll be interested in how these other clutches perform.

I only broke-in my clutch a little in my driveway before I beat on it, and it felt great...just wondering what will happen a few miles down the road, especially when I strap on the supercharger.

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DECALS,FIERO SHOWS,STUFF...www.purplefiero.com

JD, what clutch are you running? Did it always slip?

GULP! Sintered Metal all around, you're hardcore ;D) Quick tip; buy another Archie flywheel. (you can't exactly get these at parts stores) while the metal clutches do holt a lot of juice, they can tend to be, ah, more 'agressive' on your flywheel )

Let us all know the nitty gritty when you get the rest of your car back together. I've been following it closely, totally awesome )

Best!
Ben.

------------------

Ben Cannon
88 Formula, T-top, Metalic Red. (2:13.138 at Sears Point) "Every Man Dies, not every man really Lives"
88 Formula, Northstar, Silver, In-Progreess. -Mel Gibson, "Braveheart"

quote Originally posted by artherd: GULP! Sintered Metal all around, you're hardcore ;D) Quick tip; buy another Archie flywheel. (you can't exactly get these at parts stores) while the metal clutches do holt a lot of juice, they can tend to be, ah, more 'agressive' on your flywheel ) Let us all know the nitty gritty when you get the rest of your car back together. I've been following it closely, totally awesome ) Best! Ben.

Is that what it looks like to you? They told me that it was a carbon/ceramic composite? Are you sure? I might want to call him in the AM and inquire! If it is actually a sintered metal clutch, what are the advantages/disadvantages? I'm assuming it eats the flywheel as well (metal on metal). Would I get the miles out of it and just have to replace both the flywheel and clutch at the same time? Anyone have experience with sintered metal clutches?

Rob D.

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Modified 2.8 (Soon to be a 383 V8 )
2.5" Drop
11" Brakes
17" Revolutions
RCC Coilover Suspension

Hmm...looks like metal to me (I've never bought a metal clutch, mind you). A carbon/ceramic would be a lot darker in color (carbon being black). I'd make a call and verify what you've got.

*bump*

Bryce
88 GT

Is it an illusion or are the rivets retaining the pads, very close to the surface? It appears that you wouldn't have to lose much lining material before they contact the flywheel.

I'm not a clutch design expert, and I'd cetainly want to understand why you wouldn't have to worry about this.

Can't wait the hear your test results and durability, I may be wrong, but I don't think it's going to last very long, pretty small surface area for transfering torque. Also can you let us know your HP/Torque numbers, trans model, make, and size tires?

Oddly enough, the small surface area is good (well, sort of, it means it won't slip as easially ) Keeping the pressure plate the same stregenth (say 2,000lbs) if you decrease the surface area of the disc, you *increase* the loading/per-square-inch.

It *does* look like metal from here, but I sure can't say for sure. It's entirely possible that a ceramic/carbon hybrid could have almost any colour (depending on where/how the carbon is mixed with the ceramic meterial, and in what proportions, and what colour the raw ceramic was...)

What it boils down to is: It's gonna chatter a bit (I bet) and yeah, I'd just replace the flywheel when you replace the clutch. It should last quite a while, wether it's made of metal or ceramic/carbon, it ain't going to wear-down very fast! (probally at close to the same rate as the flywheel, grin )

Just thinking about your next clutch change (I do expect you'll get some decent mileage out of it, unless it slips, which I'm betting it won't; a steel/steel frictional coefficent is huge!) But yeah, when you pull it, you'll want to NOT be out of flywheels )

Let us all know how it goes, looking forward to seeing your car!

Best!
Ben

------------------

Ben Cannon
88 Formula, T-top, Metalic Red. (2:13.138 at Sears Point) "Every Man Dies, not every man really Lives"
88 Formula, Northstar, Silver, In-Progreess. -Mel Gibson, "Braveheart"

Chester,

I am afraid you are going to learn to hate that clutch, unless all you do is race. That thing is going to chatter your teeth out of your head and shake like you are on an old dirt road if you attempt to let it out easy after it has been heated up (heavy traffic, etc).

This is much like my RAM 900 clutch, but even more aggressive.

Notice the individual pads on the disc in my picture here. This clutch is super tight, holds tons of power, but is terrible in "normal" driving situations.

Well, I've only been on the PFF for about 3 days now and yeah, this is one of the most informative threads. I love it!! So insperational. My knowledge is quite inadequate making this thread out of my league but I just wanted to say that this thread is bad a$$!! I have an '87 2.5 with an auto tranny that I'll be putting a V-8 in. I've also been discussing possibly changing to a manual tranny. This thread sales me. I want a Manual!! Thanks guys.

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"The key to comprehension: That which is complex you break down simply and that which is simple you understand complexily creating an ever ending cycle of comprehension." -Skinner

It might not have much pad before the rivets, but it shouldn't wear anything like an organic pad. The flywheel will be showing the wear. I could chirp the tires into third gear with a stock pressure plate, 4-puck unsprung clutchnet disc and a V6! It's more streetable than you think. You just get used to it... I put a couple thousand VERY HARD miles on this setup combined with the punishment 1FST2M6 gave it with nitrous oxide and it still worked perfectly when I pulled the engine. The flywheel was worn a bit, but not as bad as you'd think! For a V8 I'm using a better pressure plate, and clutchnet just replied about it, so we'll see what they offer.

Hi all,

Just got back on the forum since on the trip to Carlisle. I called David at SPEC the day after Arthurd posted the possibility of the disk being made of cintered metal. They claim that IT IS NOT CINTERED METAL! Its a ceramic/carbon composite material. Claims it will have a smooth engagement once broken in. We shall see. I showed it to "The Man" and he told me it was "Purdy" Hi Archie! Anyway, I'll post the story of the trip and conversation with SPEC and Archie when I get back. For those that wanted to know what the specs on the conversion are, I'm going with a custom built 383 stroker that was slightly detuned on the cam for the Edelbrock Pro-Flow fuel injection system. Motor rating out of the crate was 465 HP/ 469 Ft/Lbs of torque before we detuned the cam some. Will be mated to a Getrag. I'm hoping to get around 425/440 at the least before we do some tuning. I cant' friggen wait!!!!!! I had Archie fire up his Fino with the dual cat exhaust. Ahhhhhhh, music to my ears. Now if I could just snap my fingers and have it ALL done! So, catch you guys once I'm home. Time to pack and head NORTH !

------------------

Modified 2.8 (Soon to be a 383 V8 )
2.5" Drop
11" Brakes
17" Revolutions
RCC Coilover Suspension

Ok, well we made it back from Carlisle. Pretty interesting trip. Anyway, have most everything for the swap now but the motor. It should be here in 2 weeks then on to the testing I'll post my findings as I go along.

Rob D.

Zowie! Zats one hot motor! ;D)

Best!
Ben.

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Ben Cannon
88 Formula, T-top, Metalic Red. (2:13.138 at Sears Point) "Every Man Dies, not every man really Lives"
88 Formula, Northstar, Silver, In-Progreess. -Mel Gibson, "Braveheart"