Centerforce Dual Friction clutch observations

[brian89gp]

This is meant in no way to discourage you from getting CF clutch for your 284, but maybe it will open up a couple options. This is in comparison to a factory clutch I just picked up.

The pressure plate appears to be the same, just painted oragne. Eyeballing it I can tell no difference aside from the CF has what looks like a balancing weight on it. CF won't tell me the clamping load of the pressure plate or even if they modified it in some way, their loss.

The disc bears a striking resemblence to stock. All that it appears that they did was drill the outer disc rivits off (the ones that hold the friction material sides together) and replace the flywheel side with an 8 puc version. Same center section down to the little "DK" symbol. I have heard that the stock clutch is organic, and guess what, the pucs are made out of the same material down to the copper looking fibers in it.

[Cliff8928]

Same thing that i observed with the centerforce i had... Although i think the disc in mine actually looked MORE like a stock one...

I wasn't really impressed with it at all... That's why i went with the Clutchmasters for my next (and current) car

Cliff Scott
89 BerettaGT
89 Volvo740

[Anonymous]

The whole point of a centerforce clutch is the weights in the center on that ring. They are able to apply a lot more pressure on your clutch, essentially not wearing it as fast. Other than that, it should look the same, except orange

[brian89gp]

There aren't weights on a 284 CF clutch.

[GPXSS]

*edit* Spec clutch here (not clutchmasters as I had thought)
Kevlar 282 clutch, no weights

[RacerX11]

There aren't weights any any of the FWD CF clutches I have seen (Several GM, DSM, and Honda). There just isn't enough room in the tight FWD bellhousings for the weights. Without the weights, the CF doesn't have any advantage over any other performance clutch upgrade. Not worth the cost IMO.

Marty

[Cliff8928]

Clutchmasters here
Kevlar 282 clutch, no weights

Compared to the Clutchmasters Kevlar, The centerforce has been


Cliff Scott
89 BerettaGT <-Clutchmasters Kevlar!
89 Volvo740

[BowtieKid79]

Not only will weights not fit in a FWD bellhousing, but they would never work on a pull type clutch. the point of the weights it to apply more pressre (pull outward from centrifugal force) as the rpms increase. the 284 clutch releases when pulled outward... this would decrease the clamp load with higher rpms.

I also have a clutchmasters kevlar clutch... aside from the first pressure plate blowing up.. i have had good luck with it. It seems to hold the power decently after the kevlar pucks heat up.

The CF is just shit in every way. I remember Chris S. calling them and talking to one of their tech guys and he was told that the do nothing to the pressure plate at all... 100% stock clamp load. The only thing they changed is the disc... which uses the stock, weak hub. A complete POS IMO.

[Norm '88 GT]

My buddy that has 2.8l turbo Fiero(117 MPH traps speeds) said he went through a bunch of the off the counter clutch like CF, Clutchmasters, Ram... as they all buy OE rebuildables and slap their material of choice on. He has, and his buddy has on his 3.4 DOHC turbo fiero, Clutchnet.com. They are built from scratch and use sintered pad. Which might wear faster with it's sintered pad than the softer kevlar and such. My OE clutch with 50K miles is fine for the street.

[BowtieKid79]

Most places do just reface the disc and call it good. Clutchmasters does not do that however. The pressure plate is disassembled and re-arched (heated and bent) for higher clamp load. Each PP comes with a sticker telling you what clamp load it tested at. The diaphram is also a different color than stock from the heating. I dont think CF does that. In the case of the 284, there is only ONE pressure plate made and anything otehr than stock has to be reworked. FYI.. the stage III kevlar clutchmaster kit for the 284 is rated at 2200# clamp load. It seems to be holding 270hp just fine.

[Norm '88 GT]

Mike, I don't think it is hp that kills a clutch or causes it to slip. It is torque down low in the RPM band. Something the DOHC does not have to worry about regardless of how modified when compared to a two valve setup.

Here is a note from Steve Hamm a few weeks ago when I asked him about clutches. He and his buddy both have Fieros which are not used as daily drivers year around and are using Clutchnet.



"Most all the kevlar and such are built on a stock clutch disc. Basically they buy a rebuilders clutch disk, hub paddles ect and rivet their "high performance" lining on it. If you have enough power and traction you will rip the hub right out of the disc, which is why ram tells you not to use slicks with their power grip clutch. The Sintered metal discs wear the flywheel and pressure plate faster, and wont last forever, but for the ultimate torque capacity there really isn't anything better. My buddy with the DOHC turbo fiero has the setup I suggested and he dyno'd a little over 315hp and the clutch seems fine. I ran that same setup and it worked well for me. Most all clutch masters, center force, ram, and others that offer dual friction or Kevlar clutches are built on a stock disc, the clutch net is not, and that is why I think it is so much better. Mine has a billet 4340 center section and I actually take the rivets out of the disc assembly and bolt them together for more strength."



I have 5-6 psi at peak torque and the OE clutch will not slip driving in traffic and highway merging. If I would shift more aggressively/mis-shift timing or use lower gear I probably could make it slip though.

[BowtieKid79]

Torgue down low is not the only variable that will allow a clutch to slip. I actually had problems with my kevlar unit slipping (yes i drove it easy and allowed it to break in for the first 500mi). i ended up having clutch masters re arch the pp yet again to an even higher clamp load. No matter how much low end you have... if the car only weighs 1000# (just an example), the clutch is not likely to slip. My point.. you also have to comsider the resistence against the clutch (i.e. the weight of the car and gearing), not just the input to the clutch. Its a lot harder to get a 3500# lumina moving than it is a 2700# beretta or fiero. When you shift at 7100 and the rpms drop to 5000 (where peak tq is) then its putting a lot of stress on the clutch and is more prone to slipping. The amount of tire you have on the road is also important.


The kevlar discs that clutchmaster makes ia NOT based off a stock disc (i know for a fact and have pics to prove it). I also have a ceramic 6 puc for my 284 (from clutchnet) right in front of me and it also is not based of a stock disc. the only "performance" (if you can call it that) disc that is a stocker is the CF.

BTW... hows that crank pulley working out for ya?

[brian89gp]

Well, I have been having bad luck with clutchnet. The first disc they sent looked a little to big for my tastes so I called them and asked for a slightly smaller one (very specifically a 9 5/8" disc). I looked at the disc later and the center section with the splines in it, they put it in backwards on the larger disc, I tried bolting it on and it stuck up so far the TOB wouldn't snap into the plate. Then the other disc came from clutchnet and guess what, its 9 3/8" but at least the spline piece is in the correct way.

So, since I bought a stock replacement to use the pressure plate I'm putting in the stock disc as well. I'll just have to drive it nicely for a while till I feel motivated enough to put another disc in. Shouldn't be too hard, its my only car and I cannot afford to have anything break.

[Norm '88 GT]

Mike, the 7" crank is working great. Thanks! Engaging the clutch abruptly at peak torque will have a negative effect also. If I am in a hurry to engage third gear near 3500 rpms the engine and tach zing and the car does not accelerate. :P

Yeah, I forgot you have 3 Cliff's on board with Happy Meals.

brian89gp, thanks for the feedback.

[Cliff8928]

Yeah, I forgot you have 3 Cliff's on board with Happy Meals.

Norm! I'm gonna have to figure out a way to get you back for that one =)


On a side note, The clutch disc i got for my car (with the 282) sure looked like it was a re-lined stock unit (CM# 04-088-HDTZ).. still works well though

Cliff Scott
89 BerettaGT
89 Volvo740