Spec Stage 3 or Centerforce DF

[86Cutlass383SR]

While I have my engine out rebuilding it, I'm planning ahead for my clutch/pressure plate and maybe flywheel choices. Here's my setup so far...what would you reuse or change? I need/want opinoins. This is a street only car that will never see any real strip action or stickie rear tires. Engine is a 383 SBC about 500 lb/ft torque with 2 pc RMS.

86 Cutlass with 87 f-body pedals. Speed Direct mechanical linkage for a 78-80 a/g-body. 2pc rear seal T5 flywheel and 83 f-body Lakewood bellhousing. Aftermarket T56 transmission.

I'd like to stay with the linkage setup so I can retain my bellhousing and I didn't really care for the f-body hydraulics that I replaced.

Now for my questions. Resurface and reuse stock flywheel or replace with aftermarket steel? My Spec Stage 3 clutch/pp had a very stiff pedal and was either in or out...seemed like there was no modulating it. Remember...this is a street car and stop light to stop light usage. Would the Centerforce DF have any softer pedal feel and still hold?

Thanks

Doug

[ProdigyCustoms]

The CenterForce DF 11" will be fine for your application and I would not run a stock cast flywheel in anything but a bone stock motor. A Billet SFI flyweheel and 11" DF clutch will run about $550 and is a good set up, SFI safe, good on the leg, NO ON / OFF problems, and lighter then your stock cast wheel, and totally capable of handling your power.

Were doing a TKO 600 conversion on Michaels 383 CI, 1986 Monte Carlo today in fact. This is the exact set up we are putting in his car, and his horsepower / torque should be real close to yours on motor he runs a little nitrous too, but were not worried, the clutch will take it.

[86Cutlass383SR]

Will an 11" clutch/flywheel fit into the 83 f-body Lakewood bellhousing? I was under the understanding they could only handle a 10.5" setup.

Doug

[ProdigyCustoms]

Well, I have not used that bell yet, On Michael's Monte we are using a Standard SBC Lakewodd bell and made a bracket for the slave. That bellhousing clears a 12" set up. Your will require a couple phone calls to Lakewood / Centerforce

[86Cutlass383SR]

I just sent Lakewood an email asking that question.

My car has progressed from a 350 with T5 to a 383 with Aftermarket T56 is the reason I'm working with that particular bellhousing. Was using the 87 hydraulics with the stock bell and wanted to switch to the mech linkage. I couldn't find a stock 82-83 bell so I bought the Lakewood mech linkage (15015) bell.

Doug

[68sixspeed]

500 ft-lbs might be over the torque rating of the 11" dual friction- I'd call centerforce to check, their tech guys are very helpful.. At the very least, if you do a dual friction, you don't plan on running slicks or drag radials. I burned through a few dual frictions on slicks with my 358 making 450ft-lbs. I'm running the DF pressure plate with the LM disk on my 427 with good luck.

[ProdigyCustoms]

This is a street only car that will never see any real strip action or stickie rear tires.
Thanks

Doug

The 11" will be fine.

[86Cutlass383SR]

I'll call Lakewood tomorrow and find out if it'll fit.

Thanks Frank!

Doug

[68sixspeed]

Frank, I'm usually with you on most things, but having shredded DF clutches on slicks, and had them slip on the street (it's replacement, not one that had seen track use) with a 450 ft-lb motor, I'm trying to throw in a bit of first hand experience... if I can make it slip (granted, with some spirited driving), with 450ft-lb 358 with a 3.01 first gear and 4.10 rear, it's borderline to under-rated for that application; throw in another 50ft-lbs and unknown gearing parameters, he might not be ok, that's all. When I would do a hard 1-2 shift or a 2-3 shift with anything but a cold clutch, the 358 could pull through the clutch-- not good.; but, it's just my opinion too.

That being said, I still run centerforce products, I've just found the combo of the DF's pressure plate with the LM's clutch disk really good, and it it can take my 550-ftlbs and my lead foot, it's alright by me.

[86Cutlass383SR]

What is the "LM" clutch?

Doug

[86Cutlass383SR]

I'll answer my own question since I found the answer. The Light Metal clutch.

Doug

[68sixspeed]

yep, light metal; nice road race clutch, but expensive to get the weight savings; the lm clutch disk has increased torque capacity though. I tried it when I did the motor upgrade on suggestion of the guys at centerforce. I was asking about the DFX clutch, but it sounded a bit so-so for a lot of driving. Basically the DF has the organic material on one side, and pucks of another material on the other (hence dual-friction); the LM has the pucks on both sides. Made sense to me since I've never had the puck side slip or give up, it's always the organic side that slips or rips apart in one case. Hope it helps! -Dan

[86Cutlass383SR]

68sixspeed I have 2 questions.

How is the pedal feel? light like a stock unit, slightly heaver or stiff.

Is your setup able to be modulated or is it *off or on*?

General question for anyone in particular. Where does the Modulatibility (is that even a word...?) come from? The makeup of the clutch or the stiffness of the pressure plate? Or a combonation of the two?

Doug

[68sixspeed]

Pedal feel is good, the LM bites a touch harder than the DF, but not that much (once broken in at least). I've talked to 2 people with the DFX, they like it for the abuse it can take, but it is touchy/grabby. I drive my car a lot, it went from CT to Carlisle PA last year, and to Maple Grove PA the year before, so that covers highway, a lot of in town cruising, sitting in traffic on the interstate, etc. I think it's good; but I'm glad it isn't more aggressive too!

The pedal feel (force/weight) is the pressure is the pressure plate; their use to be a joke about the guys running the borg-beck style that you could spot them by their huge left leg muscles. Most diaphram clutches like the centerforce have good manners from a force aspect. The down side is that some people say that diaphram doesn't release as well at high rpm, so a lot of people that need 7000+ shift points are going to the long style. (I'm thinking of one for my '69) -Dan

[86Cutlass383SR]

Ok...update. According to Lakewood, the 11" flywheel will fit into my 15015 bellhousing which is an 82-83 mechanical linkage T5 bellhousing. If he is correct then I would tend to assume (and you know what they say about *assuming*) then the 11" would also fit into the 15020 hydraulic linkage version.

Doug

[ProdigyCustoms]

I thought the 11" would fit, for your purspose, you will be fine with the 11"

[86Cutlass383SR]

Ok...Thanks Frank!

Doug

[3pedals]

the LM clutches have bronze metalic linings, so they will be a bit more "grabby" compared to the DF, and any other organic lining, but they will also hold more power with the same clamp pressure.

[68sixspeed]

3pedals, are you sure on the bronze? The DFX might be, but the 'pucks' on the LM appear the same as the ones on the back (non-organic) side of the DF, there is definately primarily non-metalic material making them up. Just curiosity, that's all... all I know is it works!

[hotrodf1]

I can't figure how the Stage III isn't getting the job done. I love mine! Very easy to drive with the hydraulic T-56 style slave / master combo. Mech. linkage ain't got crap on hydraulic.

I did have to change my clutch pedal ratio to make it a little less touchy, but that was probably because my Wilwood clutch master had a little more diameter than it should have. But seriously, the stage III works almost as good as the stock clutch in my old 95 TA 6sp.

You say it is on / off, and very touchy? Ah. I just read that you have mechanical. That's where the issue is I think. My buddies stang has a Spec III in it with mechanical linkage, and it will make you leg quiver sitting at a stoplight. With hydraulic, like a stock F-body pretty much - very comfortable around town in my ride.

DId you ever try the stage III with the hydraulic? Maybe your bell housing will not accept that setup? I know the stock F-body lines have some kind of flow restriction in them somewhere, I think to protect the clutch/tranny or something (factory warranty type stuff). I think I read that in GM High Tech Perf. mag or something. That can give people issues at the track I think. I just ran a steel line from the Wilwood to the stock replacement slave, used the adapter from McCloed. No restriction in my lines.

Maybe I shouldn't be asking these questions, I dunno, I just hate to see you throw out a (what I believe) nice clutch. Besides, the Spec III holds 700HP, I have made plenty of passes on mine on the bottle and thrashed a good bit with the Vortech - Stage III takes it in stride.

Anyway, good luck with whatever you choose!